Featured ArticleResearch Articles, Systems/Circuits

PVN–NAc Shell–VP Circuit OT and OTR Neurons Regulate Pair Bonding via D2R and D1R

Lizi Zhang, Yishan Qu, Lu Li, Yahan Sun, Wei Qian, Jiayu Xiao, Kaizhe Huang, Xiao Han, Haiwei Niu, Luoman Li, Jing Liu, Hui Qiao, Rui Jia, Ting Lian, Zhixiong He and Fadao Tai
Journal of Neuroscience 11 June 2025, 45 (24) e2061242025; https://doi.org/10.1523/JNEUROSCI.2061-24.2025

Abstract

Previous studies have found that several neurochemicals are involved in formation of pair bonding. However, the circuit mechanisms underlying pair bonding, especially how these chemicals interact in this circuit to regulate pair bonding, remain unclear. Using male mandarin voles, the present study shows that cohabitation with a partner increased the frequency of spontaneous excitatory postsynaptic current (sEPSC) of paraventricular nucleus (PVN) oxytocin (OT) neurons projecting to the nucleus accumbens (NAc) shell. Optogenetic activation of PVN OT neurons projecting to the NAc shell reduced the activity of D2 medium spiny neurons (MSNs) but increased the activity of D1 MSNs in the NAc shell. Bath application of OT caused a long-term depression (LTD) of evoked excitatory postsynaptic current (eEPSC) in NAc shell D1/D2 MSNs in the noncohabitated male voles. This OT-induced LTD in the NAc shell D1/D2 MSNs was suppressed by 7 d of cohabitation. NAc shell oxytocin receptor (OTR) MSNs projecting to the ventral pallidum (VP) were D1R/D2R positive. Chemogenetic activation or inhibition of OTR MSNs in the NAc shell projecting to the VP facilitated or disrupted the pair bond formation, respectively. The facilitatory effects of OTR MSN activation on pair bond formation could be blocked by D2 antagonist, but not D1 antagonist. These results suggest that OT and OTR neurons in the PVN–NAc shell–VP circuit regulate pair bonding via different activities of D1/D2 MSNs.

Significance Statement

Pair bond is important for successful reproduction in monogamous species, while the mechanisms by which the neurochemicals interact to regulate formation of pair bonding remain unclear. Using whole-cell patch-clamp recordings, we confirmed that cohabitation with opposite sexes alters the synaptic transmission of OT neurons in the PVN and the effects of OT on D1 and D2 medium spiny neurons (MSNs) in the NAc. We then unveiled that optogenetic activation of PVN OT neurons influences activities of D1 and D2 MSNs in the NAc shell and manipulation of VP-projecting OTR MSNs in the NAc shell affected pair bonding formation. Our findings identify that OT and dopamine system interact in the PVN–NAc shell–VP neural circuits modulating formation of pair bonding.

Introduction

Neurochemicals such as nonapeptides and dopamine have been found to play important roles in pair bonding (Carter et al., 1995, 1997; Young et al., 2011; Perkeybile and Bales, 2017; Carter and Perkeybile, 2018). Little is known about the mechanism by which these neurochemicals interact in specific circuits to regulate formation of pair bonding. Elucidating these neurobiological mechanisms provides critical insights into the complex processes underlying social bonds, including romantic partnerships.

Oxytocin (OT) is crucial for social cognition and behavior, and it is speculated to regulate pair bonding (Murakami et al., 2011; Burkett et al., 2016; Li et al., 2019, 2020). Study shows that exogenously administered OT can facilitate pair bonds in females (Cho et al., 1999). Study also shows that lateral ventricle infusion of OTA impaired partner preference indicating a key role of endogenous OT in the formation of pair bonding in male prairie voles (Johnson et al., 2016). Furthermore, intracerebroventricular injection of OT into female prairie voles can facilitate formation of pair bonding, while an oxytocin receptor (OTR) antagonist blocks it (Williams et al., 1994; Insel and Hulihan, 1995). However, the electrophysiological and circuit mechanisms by which the OT system regulates the formation of pair bonding remain unclear.

OT and dopamine (DA) synergistically regulate social interaction and motivation (Aragona et al., 2006; Skuse and Gallagher, 2009; Love, 2014; Song et al., 2016 ; Borland et al., 2019). Some studies suggest an interaction between OT and dopamine in regulation of pair bonding (Liu and Wang, 2003; Smeltzer et al., 2006). In the nucleus accumbens (NAc), facilitatory effects of OT on partner preference can be suppressed by blocking of D2R, while facilitatory effects of D2R agonist on partner preference can be blocked by OTR antagonist (Liu and Wang, 2003). D2R and OTR may form D2-OTR heteromers in the NAc to inhibit γ-aminobutyric acid (GABA) inputs of NAc medium spiny neurons (MSNs) to downstream ventral pallidum (VP) and result in activation of VP and strengthening of synapse transmission (Romero-Fernandez et al., 2013). Although pharmacological studies have revealed a synergistic effect of OT and DA in the regulation of pair bonding formation, how OT and DA interact in specific circuits to affect formation of pair bonding remains unclear.

OTR in the NAc is critical for social behavior and partner preference (Insel and Shapiro, 1992; Dölen and Malenka, 2014). In adult female prairie voles, injection of OTR agonist or antagonist can facilitate or disrupt partner preference (Williams et al., 1994; Insel et al., 1998). Overexpression of OTR via AAV facilitates partner preference (Ross et al., 2009a; Keebaugh and Young, 2011), while interference with OTR mRNA expression disrupts partner preference in prairie voles (Keebaugh et al., 2015). It is also found that mating can enhance OTR expression in the NAc and subsequently facilitate formation of pair bonding (Wang et al., 2013; Duclot et al., 2016). Levels of OTR in the NAc of monogamous prairie voles are higher than those in polygamous montane voles (Insel and Shapiro, 1992). However, the causal role of OTR MSNs in the NAc shell projecting to VP in formation of pair bonding remains unclear, and whether this role is also regulated by D1R/D2R needs further investigation.

The present study used monogamous mandarin voles (Microtus mandarinus) as an animal model. The patch clamp was used to observe the effects of cohabitation on synaptic transmission of OT neurons. Optogenetic method combined with calcium imaging was used to determine whether the activity of PVN OT neurons projecting to NAc affects the activities of D2/D1 MSNs. Patch clamp was also used to investigate the effects of OT and cohabitation on electrophysiology of NAc shell D1/D2 MSNs. Chemogenetics combined with pharmacological methods was used to determine the causal roles of OTR MSNs in formation of pair bonding and the involvement of D1/D2. This study aims to elucidate how OT and DA interact in the PVN–NAc shell–VP circuits to regulate formation of pair bonding.

Materials and Methods

Animals

Subjects used in the present study were the F2 generation of mandarin voles bred in the laboratory. The voles were weaned at 21 d after birth and lived in same-sex colonies in different polycarbonate cages (44 cm × 22 cm × 16 cm) and were housed in a temperature-controlled environment of 22–24°C, 12 h light/dark cycle with food and water ad libitum. The voles used in the experiment were approximately 70–90 d old. All experimental procedures were conducted in accordance with the Guidelines for the Care and Use of Laboratory Animals in China and the regulations of the Animal Care and Use Committee of Shaanxi Normal University.

Virus

Table 1 presents the viral constructs used in this study and their identifiers, serotype titers, and sources.

Stereotaxic surgery and virus infusions

Male mandarin voles were anesthetized with 1.5–3.0% isoflurane inhalant gas (R5-22-10, RWD Life Science) and fixed on a stereotaxic apparatus (68045, RWD Life Science). The brain coordinates of virus injection were as follows: NAc shell, AP +1.5, ML ±0.99, DV −4.2; VP, AP +0.8, ML ±1.2, DV −4.9; PVN, AP −0.4, ML 0, DV −5.35. Next, a 10 µl Hamilton microsyringe (7635-01, Hamilton) was used to inject the virus using a microsyringe pump (KDS Legato 130, RWD Life Science) at a rate of 80 nl/min. After the injection, the syringe needle was left in place for 10 min and was then slowly removed to prevent virus leakage. For fiber photometry recording, voles were mounted on a stereotaxic apparatus, and a fiber-optic cannula (diameter, 2.5 mm; NA, 0.37; depth, 6 mm; RWD Life Science) was implanted into the site approximately 0.15 mm above the NAc shell 10 d after virus injection. Only voles with the correct locations of virus expression and optical fibers were used for further analyses.

View this table:
Table 1.

Information about virus used in experiments

Alterations in the synaptic plasticity of PVN OT neurons projecting to NAc shell after cohabitation were recorded using whole-cell patch-clamp recordings. Voles were divided into a control (no cohabitation with females) group and a cohabitation group. Voles were injected with rAAV(Retro)-Oxytocin-Cre-WPREs-pA (400 nl) into the NAc shell and rAAV-EF1α-DIO-mCherry (400 nl) into the PVN to identify PVN OT neurons projecting to the NAc shell. Three weeks after virus injection, the males were cohabitated with females for 7 d.

For recording the activity of two types of MSNs in the NAc shell, we injected unilaterally rAAV-D1-GCaMP6m (400 nl) and rAAV-D2-GCaMP6m (400 nl) into the NAc shell. For the optogenetic activation of PVN OT neurons projecting to NAc shell, we injected unilaterally rAAV-hSyn-DIO-ChrimsonR-mCherry-WPRE-hGH (400 nl)/rAAV-EF1α-DIO-mCherry (400 nl) into the PVN and rAAV(Retro)-Oxytocin-Cre-WPREs-pA (400 nl) into the NAc shell. After 3 weeks of virus injection, an optical fiber was placed in the NAc shell, and an optical fiber was placed in the PVN. Voles were allowed to recover for 1 week before testing. The viruses were purchased from BrainVTA company. The noncoding promoter sequence of the mouse D1R/D2R gene was predicted and amplified for validation. The sequence was then constructed and packaged by the AAV virus vector by the BrainVTA company. The detailed sequence information can be obtained from the BrainVTA company.

Alterations in the effect of OT on NAc shell D1/D2 MSNs after cohabitation were then examined using whole-cell patch-clamp recordings. Voles were divided into a control (no cohabitation with females) group and a cohabitation group. Voles were injected with rAAV-D1-mCherry (400 nl) or rAAV-D2-mCherry (400 nl) into the NAc shell to identify D1/D2 MSNs. Three weeks after virus injection, the males were cohabitated with females for 7 d.

Next, to verify the distribution of NAc shell VP-projected OTR MSN colabeling with D1R/D2R, 250 nl of rAAV-D1-mCherry or rAAV-D2-mCherry was injected into the NAc shell. Three weeks after injection of rAAV-D1-mCherry or rAAV-D2-mCherry, 150 nl of Alexa Fluor 488 cholera toxin subunit B (CTB) was injected into the VP. Brains were collected 10 d after CTB injection. Voles with correct injected sites were used for analysis (D1, n = 3 voles; D2, n = 3 voles).

Then, the chemogenetic approach was used to activate or inhibit NAc shell OTR MSNs projecting to VP to disclose the role of VP-projected OTR MSNs in the NAc shell in pair bond formation. rAAV-EF1α-DIO-hM3Dq(Gq)-mCherry (400 nl), rAAV-EF1α-DIO-hM4Di(Gi)-mCherry (400 nl), or rAAV-EF1α-DIO-mCherry (400 nl) was bilaterally injected into the NAc shell, and rAAV (Retro)-OTR-Cre-WPRE-pA (400 nl) was injected into the VP. The OTR promoter sequences were originated from mandarin voles. Subjects were divided into Gq, Gi, and mCherry groups. The partner preference test was conducted on Days 3 and 7 of cohabitation.

Finally, VP-projected OTR MSNs were chemogenetically activated as previously described. Meanwhile, we used D1/D2 antagonist on Days 3 and 7 of cohabitation to reveal different roles of these two types of DA receptors in the NAc shell VP-projected OTR MSNs in the pair bond formation. rAAV-EF1α-DIO-hM3Dq(Gq)-mCherry (400 nl) was bilaterally injected into the NAc shell, and rAAV (Retro)-OTR-Cre-WPRE-pA (400 nl) was injected into the VP. After 3 weeks of virus injection, cannulas were bilaterally placed in the NAc shell. Subjects were divided into D1 antagonist, D2 antagonist, and vehicle groups. The partner preference test was conducted on Days 3 and 7 of cohabitation.

All female voles were ovariectomized and primed through subcutaneous administration of estradiol benzoate (17-β-Estradiol-3-Benzoate, Sigma-Aldrich, 2 μg dissolved in sesame oil starting 3 d prior to the experiments; Borie et al., 2022).

Fiber photometry

The fiber photometry system (ThinkerTech) was used as previously described (Zhang et al., 2024). Briefly, the emission light from a modulated blue 480 LED (50 mW) was reflected with a dichroic mirror and then delivered to the brain by an optical objective lens coupled with an optical commutator, which excited the D1/D2-GCaMP6m located in the NAc shell. The excitation light was passed through another bandpass filter, into a CMOS detector (Thorlabs; DCC3240M), and finally recorded by LabVIEW software (TDMS Viewer, ThinkerTech).

On testing days, voles were anesthetized with isoflurane and connected to a multimode optic fiber patch cord (ThinkerTech; NA, 0.37; OD, 200 μm) connected to a fiber photometry apparatus and habituated in a novel clean cage for 30 min before the test. The changes in fluorescence signals in the D1/D2 neurons in the NAc shell during optogenetic activation of NAc shell-projected OT neurons in the PVN were collected and digitalized by CamFiberPhotometry software (ThinkerTech). The recording data were analyzed using Matlab 2019a. The ΔF/F values were calculated as (F − F0)/F0, where F0 is the average of the baseline fluorescence signal. For comparisons of average calcium signals, we calculated the baseline signal from −5 to 0 s and event signal from 0 to 5 s from optogenetic activation.

Optogenetics

Three weeks after virus injection of optogenetic virus, male mandarin voles were implanted with an optical fiber (diameter, 2.5 mm; NA, 0.37; depth, 6 mm; RWD Life Science) in the PVN. Fiber photometry tests were performed 1 week later. For the activation of NAc shell-projected OT neurons in the PVN, the ChrimsonR group (D1-GCaMP6m, n = 6; D2-GCaMP6m, n = 6) received approximately 10 mW (589 nm, 15 ms, 20 Hz, 5 s light-on) in the fiber photometry tests. For the mCherry group (D1-GCaMP6m, n = 6; D2-GCaMP6m, n = 6), the same test procedure was used.

Slice preparation and whole-cell patch-clamp recording

Four weeks after virus injection of D1-mCherry/D2-mCherry virus, parasagittal slices (300 μm) containing the NAc shell were prepared from male voles using standard procedures. In brief, voles were anesthetized with 1.5–3.0% isoflurane and decapitated. Brains were then quickly placed in oxygenated artificial cerebrospinal fluid (ACSF) containing the following (in mM): 125 sodium chloride (NaCl), 2.5 potassium chloride (KCl), 25 glucose, 25 sodium hydrogen carbonate (NaHCO3), 1.25 monosodium phosphate (NaH2PO4), 2 calcium chloride (CaCl2), and 1 magnesium chloride (MgCl2), gassed with 5% CO2/95%O2. Slices were cut by Leica Vibratome with oxygenated ACSF and were incubated at 32°C for 30 min. Slices were allowed to recover for 1 h at 25°C containing artificial cerebrospinal fluid (ACSF).

Whole-cell patch-clamp recordings were obtained with a MultiClamp 700B amplifier, digitized at 10 kHz using a Digidata 1440A acquisition system with Clampex 10.2, and analyzed with pClamp 10.5 software (Molecular Devices). Only cells that maintained a stable access resistance (<30 MΩ) throughout the entire recording were analyzed. mCherry MSNs in the NAc shell were identified under IR-DIC optics and fluorescence microscopy. Electrodes were pulled from 1.5 mm borosilicate glass pipettes on a P-97 puller (Sutter Instruments). Electrode resistance was ∼5–7 MΩ when filled with internal solution containing the following (in mM): 130 CsMeSO3, 8 CsCl, 1 MgCl2, 0.3 EGTA, 10 HEPES, 4 ATP (magnesium salt), 0.3 GTP (sodium salt), and 10 phosphocreatine (pH 7.4, 300 mOsmol/kg). sEPSCs were recorded by adding PTX (100 µM, Sigma-Aldrich) in ACSF while recording at a holding potential of −70 mV (cohabitation, n = 10 cells from four voles; control, n = 8 cells from three voles). Afferents were stimulated with a bipolar nichrome wire electrode placed at the border between the NAc shell and cortex dorsal to the anterior commissure. eEPSCs were evoked at a frequency of 0.1 Hz while MSNs were voltage-clamping at −70 mV (D1 MSNs: cohabitation, n = 7 cells; control, n = 6 cells; D2 MSNs: cohabitation, n = 7 cells; control, n = 6 cells). After 10 min of baseline recording, the slices were perfused with 1 μM OT for 50 min. Input resistance and access resistance were monitored throughout each experiment, and the data were excluded if these changed by 20%.

For determining the effect of clozapine N-oxide (CNO, BrainVTA, CNO-02) in Gq or Gi virus-infected MSNs, spontaneous firing of action potentials in the MSNs was recorded in the current-clamp mode. After 3 min of baseline recording, the slices from voles with injection of Gq or Gi virus were perfused with 10 μM CNO for 7 min. The total recording time for each cell was 10 min. Electrode resistance was ∼5– 7 MΩ when filled with internal solution containing the following (in mM): 130 K-gluconate, 5 NaCl, 10 HEPES, 0.5 EGTA, 2 Mg-ATP, and 0.3 Na-GTP (pH 7.3, 280 mOsmol/kg).

Chemogenetics

Three weeks after virus injection of chemogenetic virus, male mandarin voles were cohabitated with females. For the OTR-mCherry-hM3Dq group (CNO, n = 7; saline, n = 8) or the OTR-mCherry-hM4Di group (CNO, n = 7; saline, n = 8), male voles were injected with CNO (1 mg/kg, i.p.) or saline once per day during the 7 d cohabitation period. On Days 3 and 7 of cohabitation, a partner preference test (3 h) was conducted 3 h after CNO injection. For the OTR-mCherry group (CNO, n = 8; saline, n = 8), the same test procedure was used.

Chemogenetics combined with pharmacological treatment

Three weeks after virus injection of chemogenetic virus, male mandarin voles were cohabitated with females. For the OTR-mCherry-hM3Dq group, male voles were injected with CNO (1 mg/kg, i.p.) or saline once per day during the 7 d of cohabitation. On Days 3 and 7 of cohabitation, a partner preference test (3 h) was conducted 30 min after D1/D2 antagonist injection. The D1 antagonist SCH23390 (Sigma-Aldrich, 5.05723) was prepared in saline with a final concentration of 50 ng/μl. The D2 antagonist eticlopride (Sigma-Aldrich, E101) was prepared in saline with a final concentration of 50 ng/μl. All the microinjections were administered 30 min before the behavioral test. The speed of injection was 0.1 μl/min, and the total injection volume was 0.2 µl per side for all the drugs. The injector needle was remained in situ for another 2 min for drug diffusions (SCH23390: CNO n = 8, saline n = 7; eticlopride: CNO n = 8, saline n = 7; vehicle: CNO n = 8, saline n = 7). The dose and timing of drug administration were chosen based on previous studies using SCH23390 and D2 antagonist eticlopride (Liu and Wang, 2003).

Partner preference test

The partner preference test apparatus was a three-chamber (60 cm × 40 cm × 20 cm) arena. Partner voles and unfamiliar female voles were placed into the different chambers on opposite sites. Subjects were adapted to the test apparatus for 30 min before testing. In addition, partner voles and unfamiliar female voles were also adapted to the test apparatus for 10 min. Then partner vole and unfamiliar female vole were confined to their own opposite site chambers, the subjects were then placed into the middle chamber and allowed to move freely during the 3 h of partner preference test. Real-time behaviors were videotaped and quantified by smart 3.0. A longer duration of side-by-side contact spent with partners (but not unfamiliar female voles) indicates successful formation of partner preferences. The social preference ratio was calculated as follows: (time spent on partner side − time spent on stranger side) / (time spent on partner side + time spent on stranger side).

Fluorescence in situ hybridization

To validate D1R or D2R antibodies, FISH was conducted using RNA-Protein Co-Detection Ancillary Kit (Advanced Cell Diagnostics 323180) following the manufacturer's protocol. Voles were perfused transcardially with 0.1 M PBS (pH 7.4) followed by 4% paraformaldehyde in 0.1 M PBS. Then, brains were collected and postfixed for 24 h in 4% paraformaldehyde at 4°C, followed by 24 h in 20% sucrose and 24 h in 30% sucrose, and were cut into 12 μm coronal sections using a cryostat (Leica Biosystems). Sections were mounted on slides and stored at −80°C. Probes used in this study were RNAscope Probe-Mo-Ppib (catalog #533491), RNAscope Negative Control Probe-DapB (catalog #310043), RNAscope Probe-Mo-Drd1-C3 (catalog #588161-C3), and RNAscope Probe-Mo-Drd2-C2 (catalog #534471-C2). Briefly, after pretreatment with the RNA-Protein Co-Detection Ancillary Kit, brain slices were incubated in primary antibody [D1R (1:100, NB110-60017, Novus Biologicals), D2R (1:400, sc-5303, Santa Cruz Biotechnology)] at 4°C overnight. Sections were then incubated with secondary antibody (anti-mouse goat conjugated with Alexa Fluor 488, Jackson ImmunoResearch, AB_2339072, 1:400) after hybridization with amplifiers. Sections were counterstained with DAPI (RNAscope Multiplex Fluorescent Reagent Kit v2, Advanced Cell Diagnostics 323100) for 30 s at room temperature. Glass slides were fixed with antifade solution, and coverslipped images were acquired under an Olympus microscope (Olympus BX-43, Olympus). The MSNs colabeled by D1R/D2R mRNA and D1-anti/D2-anti were quantified. In addition, 20× images including the NAc shell were acquired, and boxed areas (300 μm × 300 μm) were selected. Then, the D1-anti/D2-anti–positive cells, NAcD1/D2 mRNA (AF594)-positive cells, and colabeled cells were manually marked. These positive or merged cells were counted using the “multipoint” function of ImageJ. The numbers from three representative sections per brain were averaged as the value of each brain. The specificity ratio (%) was calculated as follows: (colabeled cells of D1R or D2R mRNA and D1-anti or D2-anti positive cells) / (D1-anti or D2-anti–positive cells).

Immunohistochemistry

Briefly, experimental mandarin voles were perfused transcardially 0.1 M PBS (pH 7.4) followed by 4% paraformaldehyde (PFA) in 0.1 M PBS. After perfusion, brains were postfixed for 3 d in 4% PFA at 4°C followed by 48 h in 20% sucrose and 48 h in 30% sucrose, cut to 40 μm coronal sections using a cryostat (Leica Biosystems). For antibody staining, brain sections were washed with 0.1 M PBS for 10 min. Brain sections were then incubated with 0.6% H2O2 for 20 min and washed three times for 5 min with 0.1 M PBS. Brain sections were then permeabilized for 20 min in 0.5% Triton X-100 and blocked with normal goat serum for 1 h at room temperature. Brain sections were then incubated in primary antibody at 4°C for 24 h. We stained for D1R (1:100, NB110-60017, Novus), D2R (1:400, sc-5303, Santa Cruz Biotechnology), OT (1:7500, MAB5296, Millipore), OTR (1:100, XM_041642487.1, produced by Mabioway; Qu et al., 2024). The production of OTR antibody totally followed the previous study by Professor Robert Froemke (Marlin et al., 2015). Brain sections were then washed with 0.1 M PBS three times for 5 min and incubated in secondary antibodies [anti-mouse goat conjugated with 488 (1:400, AB_2339072, Jackson ImmunoResearch), anti-rabbit goat conjugated with 488 (1:400, AB_2338052, Jackson ImmunoResearch), or anti-rabbit goat conjugated with 405 (1:400, A-48254, Thermo Fisher Scientific)] for 2 h at room temperature. Sections were then washed three times for 5 min in 0.1 M PBS and counterstained with DAPI for 10 min at room temperature. Sections were then washed with PBS three times for 5 min. The glass slides were fixed with antifade solution, and coverslipped images were acquired under Olympus (BX-43).

Statistical analysis

All data are represented as means ± SEM and were assessed for normality using a one-sample Kolmogorov–Smirnov test, and the Levene's test was used to confirm homogeneity of variance. Comparisons between two groups were performed either by unpaired or paired t tests. One-way analyses of variance (ANOVAs), two-way ANOVAs, or two-way repeated-measures ANOVAs were used to compare multiple groups under multiple testing conditions as appropriate. Post hoc comparisons were conducted using Bonferroni. Statistical procedures were performed using SPSS 20.0. All statistical graphs/charts were plotted via GraphPad Prism 6.0. All experiments and statistical analyses used the double-blind method. Significant levels were set at *p < 0.05, **p < 0.01, and ***p < 0.001.

Results

Cohabitation with a partner alters the synapse transmission of PVN OT neurons projecting to the NAc shell

OT was found to be involved in pair bond formation (Williams et al., 1994), while OT neuron projections in the NAc mainly originate from PVN (Lim et al., 2004; Bosch et al., 2016). However, it remains unclear whether the synapse transmission of PVN OT neurons projecting to the NAc shell changes after pair bond formation. Therefore, we first recorded the synaptic transmission of PVN OT neurons projecting to the NAc shell before and after pair bond formation. By injecting the rAAV-DIO-mCherry virus in the PVN and rAAV(Retro)-OT-cre in the NAc shell, we labeled PVN OT neurons projecting to the NAc shell. Changes in spontaneous excitatory postsynaptic current (sEPSC) in NAc shell-projected OT neurons were recorded using whole-cell patch clamp (Fig. 1A). It was found that the frequency of sEPSC in NAc shell-projected OT neurons increased significantly (two-tailed unpaired t test; frequency, t(16) = 2.906; p = 0.0103) after cohabitation, but not the amplitude (Fig. 1B–D; two-tailed unpaired t test; amplitude, t(16) = 1.686; p = 0.1112).

Figure 1.
Figure 1.

Synaptic transmission of PVN OT neurons projecting to the NAc shell changes after cohabitation. A, Timeline of experiments, schematic diagrams depicting virus injection and recording sites. B, Representative sEPSC traces from paired and noncohabitated voles. (C-D) PVN OTNAc shell-projected neurons in paired voles exhibited sEPSC with higher frequencies (C; cohabitation, n = 10 cells from four voles; control, n = 8 cells from three voles), but not peak amplitudes (D; cohabitation, n = 10 cells from four voles; control, n = 8 cells from three voles), than those observed in no cohabitated voles. Error bars = SEM. *p < 0.05. See Extended Data Table S1 for detailed statistics.

Optogenetic activation of PVN OT neurons projecting to the NAc shell affects NAc shell D1/D2 MSN activity

One study has shown that the OTR antagonist in the NAc can prevent the pair bond formation (Insel and Hulihan, 1995). In addition, MSNs in the NAc can be mainly divided into D1 MSNs and D2 MSNs. Therefore, we next examined whether activation of PVN OT neurons projecting to the NAc shell induces different in vivo activities of NAc shell D1/D2 MSNs. rAAV(Retro)-OT-cre or rAAV-D1/D2-GCaMP6m was injected into the NAc shell, and rAAV-DIO-ChrimsonR-mCherry or rAAV-DIO-mCherry was injected into the PVN. NAc shell D1/D2 MSN activities were recorded via a fiber photometry system when PVN OT neurons projecting to the NAc shell were optogenetically activated (Figs. 2A,B, 3A,B). Virus expression and site of fiber implantation are shown in Figures 2C and 3C. Post hoc histological analysis showed that 75.34% of D1-GCaMP6m cells and 76.75% of D2-GCaMP6m cells were D1R and D2R positive (Figs. 2G, 3G) in the NAc shell. In addition, 82.14% of ChrimsonR virus-infected neurons (optogenetic virus infected) were OT positive (Fig. 2C,D). The results showed that the fluorescence signal of D2 MSNs in the NAc shell decreased significantly when PVN OT neurons projecting to the NAc shell were optogenetically activated (Fig. 2H–J; repeated measure two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(1,10) = 6.287, p = 0.0311; group: F(1,10) = 6.240, p = 0.0316; treatment: F(1,10) = 6.667, p = 0.0273; ChrimsonR: baseline vs light, p = 0.0049; light: ChrimsonR vs mCherry, p = 0.0313). However, the fluorescence signal of D1 MSNs in the NAc shell increased significantly when PVN OT neurons projecting to the NAc shell were optogenetically activated (Fig. 3H–J; repeated measure two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(1,10) = 12.79, p = 0.005; group: F(1,10) = 12.80, p = 0.005; treatment: F(1,10) = 12.88, p = 0.0049; ChrimsonR: baseline vs light, p = 0.0005; light: ChrimsonR vs mCherry, p = 0.005). In addition, no significant changes were detected in the fluorescence signal in D1/D2 MSNs of voles injected with control virus without the ChrimsonR sequence in the construct (Figs. 2H–J, 3H–J).

Figure 2.
Figure 2.

NAc shell D2 medium spinous neurons (MSNs) showing decreased activity upon optogenetic activation of PVN OT neurons projecting to the NAc shell. A, Timeline of experiments. B, Schematic of the procedure used to record D2 MSN activity in the NAc shell using fiber photometry while NAc shell-projected OT neurons in the PVN were optogenetically activated. C, Overlaps of OT antibody (green), OT-ChrimsonR (red), and DAPI (blue) in the PVN. Scale bar, 100 μm. D, Statistical chart showing that OT-ChrimsonR was relatively restricted to OT-positive neurons (n = 3 voles). E, Representative traces from electrophysiological recordings showing effects of photostimulation of an OTNAc shell-projected neuron. F, Overlaps of D2-GCaMP6m (green), D2R (red), and DAPI (blue) in the NAc shell. Scale bar, 100 μm. G, Statistical chart showing that D2-GCaMP6m was relatively restricted to D2R-positive neurons (n = 3 voles). H, Heat map illustrating the calcium response (ΔF/F, %) of the NAc shell when NAc shell-projected OT neurons in the PVN while NAc shell-projected OT neurons in the PVN were photostimulated. I, Mean fluorescence signal changes in the calcium response in the ChrimsonR group (optogenetic activated group, green line) and mCherry group (control group, blue line). The shaded areas along the different colors of lines show the margins of error. J, Quantification (repeated two-way ANOVA with Bonferroni's multiple-comparisons test) of changes in calcium signals when NAc shell-projected OT neurons in the PVN were stimulated by photo (ChrimsonR group, n = 6 voles; mCherry group, n = 6 voles). All error bars = SEM. *p < 0.05. See Extended Data Table S1 for detailed statistics.

Figure 3.
Figure 3.

NAc shell D1 MSNs showing increased activity upon optogenetic activation of NAc shell-projected OT neurons in the PVN. A, Timeline of experiments. B, Schematic of the procedure used to record D1 MSN activity in the NAc shell using fiber photometry while NAc shell-projected OT neurons in the PVN were activated. C, Overlaps of OT antibody (green), OT-ChrimsonR (red), and DAPI (blue) in the PVN. Scale bar, 100 μm. D, Statistical chart showing that OT-ChrimsonR was relatively restricted to OT-positive neurons (n = 3 voles). E, Representative traces from electrophysiological recordings showing effects of photostimulation of PVN OT neurons projecting to the NAc shell. F, Overlaps of D1-GCaMP6m (green), D1R antibody (red), and DAPI (blue) in the NAc shell. Scale bar, 100 μm. G, Statistical chart showing that D1-GCaMP6m was relatively restricted to D1R-positive neurons (n = 3 voles). H, Heat map illustrating the calcium response (ΔF/F, %) of the NAc shell when optogenetic activation of NAc shell-projected OT neurons in the PVN. I, Mean fluorescence signal changes of the calcium response in the ChrimsonR group (green line) and mCherry group (blue line) NAc shell-projected OT neurons in the PVN were stimulated by photo. The shaded areas along the different colors of lines show the margins of error. J, Quantification (repeated two-way ANOVA with Bonferroni's multiple-comparisons test) of changes in calcium signals when NAc shell-projected OT neurons in the PVN were stimulated by photo (ChrimsonR group, n = 6 voles; mCherry group, n = 6 voles). All error bars = SEM. *p < 0.05, **p < 0.01, and ***p < 0.001. See Extended Data Table S1 for detailed statistics.

Cohabitation with a partner blocks the oxytocin-induced LTD in NAc shell D1/D2 MSNs

To directly explore the synaptic effect of OT within the NAc shell, we recorded evoked excitatory postsynaptic current (eEPSC) from NAc shell D1/D2 MSNs in acute slices. D1/D2 MSNs were identified by infection of the NAc shell with rAAV-D1-mCherry or rAAV-D2-mCherry virus, and eEPSCs were recorded using whole-cell patch clamp (Figs. 4A, 5A). The results showed that bath application of OT (1 μM) caused a long-term depression (LTD; D2: paired t test, t(5) = 4.303, p = 0.0077; D1: paired t test, t(5) = 5.359, p = 0.0030) of eEPSC in NAc shell D1/D2 MSNs in the noncohabitated male voles (Figs. 4B,D, 5B,D). However, the oxytocin-induced LTD in NAc shell D1/D2 MSNs was abolished (D2: paired t test, t(6) = 0.9131, p = 0.3964; D1: paired t test, t(6) = 0.4108, p = 0.6955) by cohabitation with partner for 7 d (Figs. 4C, 5C).

Figure 4.
Figure 4.

Oxytocin-induced LTD of D2 MSNs in the NAc shell changes after cohabitation. A, Timeline of experiments, schematic diagrams depicting virus injection and recording sites. B, Control group: representative traces and quantification (paired t test) of EPSC (n = 6 cells). C, Cohabitation group: representative traces and quantification (paired t test) of EPSC (n = 7 cells). D, Summary time course. E, Quantification (unpaired t test) of average posttreatment magnitude comparisons (cohabitation, n = 7 cells; control, n = 6 cells). All error bars = SEM. *p < 0.05, **p < 0.01. See Extended Data Table S1 for detailed statistics.

Figure 5.
Figure 5.

Oxytocin-induced LTD of D1 MSNs in the NAc shell changes after cohabitation. A, Timeline of experiments, schematic diagrams depicting virus injection and recording sites. B, Control group: representative traces and quantification (paired t test) of EPSC (n = 6 cells). C, Cohabitation group: representative traces and quantification (paired t test) of EPSC (n = 7 cells). D, Summary time course. E, Quantification (unpaired t test) of average posttreatment magnitude comparisons (cohabitation, n = 7 cells; control, n = 6 cells). All error bars = SEM. *p < 0.05, **p < 0.01. See Extended Data Table S1 for detailed statistics.

NAc shell OTR MSNs projecting to VP labeled by D1R/D2R

To confirm that NAc shell OTR MSNs project to the VP, we injected a retrograde tracer (CTB) conjugated to Alexa Fluor 488 into the VP (Fig. 6A). The results showed that CTB 488 was colocated with OTR in the NAc shell (Fig. 6A). We found that 52.23% of OTR MSNs in the NAc shell labeled by CTB 488 project to the VP (Fig. 6B). In addition, 46.45% of VP-projected MSNs in the NAc shell were labeled with OTR (Fig. 6B). To further explore the overlap of OTR and different DA receptors (D1R and D2R) in the NAc shell VP-projected MSNs, we injected rAAV-D1-mCherry or rAAV-D2-mCherry into the NAc shell and CTB 488 into the VP (Fig. 6C,D). The results showed that 40.07% of VP-projected OTR MSNs in the NAc shell were labeled with D1R and 49.19% of VP-projected OTR MSNs in the NAc shell were labeled with D2R (Fig. 6E,F).

Figure 6.
Figure 6.

Distribution of the OTR MSNs in the NAc shell projecting to VP and the coexpression of the OTR with D1R/D2R in the NAc shell. A, Schematic diagrams depicting virus injection and representative images of Alexa Fluor 488 CTB (green) injection sites at the VP. Scale bar, 100 μm. B, Quantitative distinction between the percentage of CTB + MSNs expressing OTR and of the OTR + MSNs expressing CTB in the NAc shell (n = 6 voles). C, Schematic diagrams depicting virus injection and representative images of Alexa Fluor 488 CTB (green) injection sites at the VP and the images of rAAV-D1-mCherry (red) injection sites at the NAc shell. Scale bar, 100 μm. D, Schematic diagrams depicting virus injection and representative images of Alexa Fluor 488 CTB (green) injection sites at the VP and the images of rAAV-D2-mCherry (red) injection sites at the NAc shell. Scale bar, 100 μm. E, Quantitative distinction between the percentage of OTR + CTB + MSNs expressing D1R or D2R (n = 3 voles). F, Left, Quantitative distinction between the percentage of D1R + CTB + MSNs expressing OTR (n = 3 voles). Right, Quantitative distinction between the percentage of D2R + CTB + MSNs expressing OTR (n = 3 voles). All error bars = SEM.

Effects of chemogenetic activation or inhibition of OTR MSNs in the NAc shell projecting to the VP on the pair bond formation

Blocking OTR with its specific antagonist prevents pair bonding in prairie voles (Williams et al., 1994; Insel and Hulihan, 1995), suggesting the importance of OTR in pair bond formation. We hypothesized that activation or inhibition of VP-projected OTR MSNs in the NAc shell would affect pair bond formation. To chemogenetically activate or inhibit VP-projected OTR MSNs in the NAc shell, we injected rAAV-DIO-hM3Dq-mCherry or rAAV-DIO-hM4Di-mCherry into the NAc shell and rAAV-(Retro)-OTR-Cre into the VP to selectively express “Gq-DREADD” or “Gi-DREADD” in NAc shell VP-projected OTR MSNs (Fig. 7A,B). Immunohistochemical staining showed that 80.85% of hM3Dq-mCherry cells coexpressed OTR (Figs. 7E). To determine whether the ligand clozapine N-oxide (CNO) could activate or inhibit VP-projecting OTR MSNs, whole-cell patch-clamp recordings were performed. The results showed that the addition of 10 μM CNO remarkably increased the frequency of action potentials in the Gq-DREADD–transfected neurons (Figs. 7C). In contrast, CNO caused a decrease in membrane potentials in Gi-DREADD–transfected neurons (Figs. 7D). These results signal the specificity and validation of this virus strategy.

Figure 7.
Figure 7.

Effects of chemogenetic manipulation of NAc shell VP-projecting OTR MSNs on the formation of partner preference. A, Timeline of experiments. B, Schematic of chemogenetic viral strategy and injection sites. C, D, Representative traces from a Gq-DREADD (C) neuron and Gi-DREADD (D) neuron after CNO bath. E, Immunohistology image showing colocalization of hM3Dq-mCherry expression (red), OTR (green), and DAPI (blue) in the NAc shell. Scale bar, 100 μm. Statistical chart showing that OTR MSNs were relatively restricted to OTR-hM3Dq-mCherry MSNs (n = 3 voles). Immunohistology image showing colocalization of hM4Di-mCherry expression (red), OTR antibody(green), and DAPI (blue) in the NAc shell. Scale bar, 100 μm. Statistical chart showing that OTR MSNs were relatively restricted to OTR-hM4Di-mCherry MSNs (n = 3 voles). Immunohistology image showing colocalization of mCherry expression (red), OTR (green), and DAPI (blue) in the NAc shell. Scale bar, 100 μm. Statistical chart showing that OTR MSNs were relatively restricted to OTR-mCherry MSNs (n = 3 voles). F, Quantification of social preference ratio in the partner preference test after 3 d of cohabitation. G–I, Quantification of side-by-side times in the partner preference test after 3 d of cohabitation. J, Quantification of social preference ratio in the partner preference test after 7 d of cohabitation. K–M, Quantification of side-by-side times in the partner preference test after 7 d of cohabitation (OTR-hM3Dq: CNO n = 7, saline n = 8; OTR-hM4Di: CNO n = 7, saline n = 8; OTR-mCherry: CNO n = 8, saline n = 8). Error bars = SEM. *p < 0.05, **p < 0.01, and ***p < 0.001. See Extended Data Table S1 for detailed statistics.

During cohabitation, CNO (1 mg/kg) or saline was intraperitoneally injected daily (Fig. 7B). The partner preference test was conducted on Days 3 and 7 of cohabitation. In general, 3 d of cohabitation cannot induce pair bond formation (Zhang et al., 2024). Subsequent behavioral studies showed that CNO-treated mandarin voles with Gq-DREADD virus infection of OTR MSNs showed increased side-by-side contacts with their partners compared with strangers in a partner preference test after 3 d of cohabitation (Fig. 7F,G; two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(2,42) = 4.618, p = 0.0154; group: F(2,42) = 2.854, p = 0.0689; treatment: F(1,42) = 1.538, p = 0.2218; Gq_Saline vs Gq_CNO, p = 0.003; Gq: repeated measure two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(1,14) = 19.53, p = 0.0006; group: F(1,14) = 3.155, p = 0.0974; treatment: F(1,14) = 2.456, p = 0.1394; CNO_Partner vs CNO_Stranger, p = 0.0008). This shows that activation of VP-projecting OTR MSNs prompted the formation of partner preferences. Nevertheless, CNO-treated voles with Gi-DREADD virus infection of VP-projecting OTR MSNs spent less time in side-by-side with their partners than with unfamiliar females in the partner preference test; moreover, such inhibition of VP-projecting OTR MSNs also blocked partner preference after 7 d of cohabitation (Fig. 7J,L; two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(2,42) = 3.451, p = 0.0410; group: F(2,42) = 3.13, p = 0.0054; treatment: F(1,42) = 5.379, p = 0.0253; Gi: repeated measure two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(1,14) = 6.568, p = 0.0225; group: F(1,14) = 2.982, p = 0.1062; treatment: F(1,14) = 0.7774, p = 0.3928; CNO_Partner vs CNO_Stranger, p = 0.029; saline_Partner vs saline_Stranger, p = 0.011). In control virus subjects, CNO had no detectable effects on the behavioral performance in tests (Fig. 7F,I,J,M; mCherry, 3 d: repeated measure two-way ANOVA, group × treatment: F(1,14) = 0.0178, p = 0.8958; group: F(1,14) = 1.740, p = 0.2083; treatment: F(1,14) = 2.362, p = 0.1466; 7 d, repeated measure two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(1,14) = 0.0094, p = 0.9243; group: F(1,14) = 0.5517, p = 0.4699; treatment: F(1,14) = 26.93, p = 0.0001; CNO_Partner vs CNO_Stranger, p = 0.0044; saline_Partner vs saline_Stranger, p = 0.0058).

Based on the results of chemogenetic manipulations described above, it was concluded that activation of OTR MSNs projecting to VP improved the formation of the pair bond while its inhibition disrupted the formation of partner preference in mandarin voles.

D2R is involved in the increased partner preference induced by chemogenetic activation of OTR MSNs in the NAc shell

In the previous study, blockade of D2R, but not D1R, prevented pair bond formation induced by OT in the NAc shell (Liu and Wang, 2003). To explore the effect of D2R and D1R in the increased partner preference induced by chemogenetic activation of OTR MSNs in the NAc shell, we used eticlopride (D2 antagonist) and SCH23390 (D1 antagonist) to investigate the possible involvement of D2R/D1R in the NAc shell OTR MSNs projecting to VP in the formation of pair bonding. Chemogenetic activation of OTR MSNs was carried out as the previous method (Fig. 7A,B). Eticlopride (200 nl/side) or SCH23390 (200 nl/side) was directly infused into the NAc shell before the partner preference test. Consistent with previous results, we found that CNO elicited enhanced partner preference (Fig. 8F,I,J,M). In addition, treatment with eticlopride significantly reduced the impact of CNO (Fig. 8F,H,J,L). However, SCH23390 had no such effect (Fig. 8F,G,J,K). In addition, saline had no effects on the impact of CNO in tests (Fig. 8F,J; F: two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(2,40) = 3.355, p = 0.045; group: F(2,40) = 3.736, p = 0.0325; treatment: F(1,40) = 11.72, p = 0.014; vehicle_CNO vs vehicle_Saline, p = 0.0006; CNO_vehicle vs CNO_D2R, p = 0.0014; D1R_CNO vs D1R_Saline, p = 0.031; I: repeated measure two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(1,14) = 32.37 p < 0.0001; group: F(1,14) = 0.1788, p = 0.6789; treatment: F(1,14) = 6.441, p = 0.0237; CNO_Partner vs CNO_Stranger, p < 0.0001; saline_Partner vs saline_Strange, p = 0.043; J: two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(2,40) = 0.1352, p = 0.8740; group: F(2,40) = 10.32, p = 0.0002; treatment: F(1,40) = 2.105 × 10−006, p = 0.9988; CNO_vehicle vs CNO_D2R, p = 0.0173; M: repeated measure two-way ANOVA with Bonferroni's multiple-comparisons test, group × treatment: F(1,14) = 1.782 p = 0.2031; group: F(1,14) = 0.5465, p = 0.472; treatment: F(1,14) = 35.81, p < 0.0001; CNO_Partner vs CNO_Stranger, p = 0.0003; saline_Partner vs saline_Strange, p = 0.0108; H: repeated measure two-way ANOVA, group × treatment: F(1,13) = 0.2442, p = 0.6294; group: F(1,13) = 4.12, p = 0.0634; treatment: F(1,13) = 2.663, p = 0.1267 ; L: repeated measure two-way ANOVA, group × treatment: F(1,13) = 0.3957, p = 0.5402; group: F(1,13) = 0.545, p = 0.4735; treatment: F(1,13) = 3.467, p = 0.0854; G: repeated measure two-way ANOVA, group × treatment: F(1,13) = 2.808, p = 0.1177; group: F(1,13) = 0.4030, p = 0.5365; treatment: F(1,13) = 0.029, p = 0.958; K: repeated measure two-way ANOVA, group × treatment: F(1,13) = 0.04, p = 0.8446; group: F(1,13) = 2.191, p = 0.1627; treatment: F(1,13) = 7.101, p = 0.0195).

Figure 8.
Figure 8.

Intra-NAc shell injection of eticlopride (D2 antagonist) reduced partner preference induced by chemogenetic activation of OTR MSNs in the NAc shell projecting to VP. A, Schematic of chemogenetic viral strategy and injection sites. B, Timeline of experiments. C, D1 antagonist injection site: immunohistology image showing histology showing the expression of OTR-hM3Dq-mCherry within the NAc shell. Scale bar, 100 μm. D, D2 antagonist injection site: immunohistology image showing histology showing the expression of OTR-hM3Dq-mCherry within the NAc shell. Scale bar, 100 μm. E, Saline injection site: immunohistology image showing histology showing the expression of OTR-hM3Dq-mCherry within the NAc shell. Scale bar, 100 μm. F, Quantification of social preference ratio in the partner preference test after 3 d of cohabitation. G–I, Quantification of side-by-side times in the partner preference test after 3 d of cohabitation. J, Quantification of social preference ratio in the partner preference test after 7 d of cohabitation. K–M, Quantification of side-by-side times in the partner preference test after 7 d of cohabitation (SCH23390: CNO n = 8, saline n = 7; eticlopride: CNO n = 8, saline n = 7; vehicle: CNO n = 8, saline n = 7). Error bars = SEM. *p < 0.05, **p < 0.01, and *** p < 0.001. See Extended Data Table S1 for detailed statistics.

Discussion

Using multiple techniques, the present study found that cohabitation with a partner enhanced synaptic transmission of sEPSCs in PVN OT neurons projecting to the NAc. Optogenetic activation of PVN OT neurons projecting to NAc produced opposite effects on the activities of D1/D2 MSNs, and OT can induce LTD on D1/D2 MSNs that can be suppressed by 7 d of cohabitation. OTR MSNs in the NAc shell projecting to the VP control the formation of pair bonding with the involvement of D2R. This study reveals that OT and OTR neurons in the PVN–NAc shell–VP circuit regulate the formation of pair bonding via D1/D2 MSN activities.

One interesting finding is that the frequency of the sEPSCs in PVN OT neurons increased significantly after the formation of pair bonding, suggesting that the PVN OT neurons are more active. These may lead to an enhanced basal excitability and activity of OT neurons, which can drive neural activation and promote OT release. This is consistent with a previous finding that most of the OT neurons are significantly activated in the PVN of paired male rats relative to the unpaired ones (Ménard et al., 2019). In addition, an increase in the extracellular OT concentration in the NAc was detected when a female prairie vole interacted with a male (Ross et al., 2009b). These mechanisms are interconnected and collectively contribute to the regulation of pair bond formation.

The OT neurons project to the nucleus accumbens, in which the DA system is involved in the formation of mate preference (Liu and Wang, 2003). How the increase of OT release affects the DR neuron activities remains unclear. Our optogenetic experiments show that PVN OT neuron activation selectively enhances D1 MSN activity while suppressing D2 MSNs in the NAc shell. Previous study reveals that activation of D2R facilitates partner preference formation (Young and Wang, 2004), whereas activation of D1R inhibits pair bonding formation (Aragona et al., 2006). Our previous fiber photometry recordings found that during pair bonding, interactions with a bonded partner suppress D2 MSN activity and potentiate D1 MSN activity, contrasting with responses to novel strangers (Zhang et al., 2024). We propose that OT release during pair bonding consolidates monogamous behavior through two mechanisms. (1) Direct modulation of DA circuitry: OT amplifies DA-driven reward signals via D1 MSN activation, reinforcing the bonded partner's salience, while suppressing D2 MSNs to reduce novelty-seeking. (2) Temporal gating of plasticity: chronic OT exposure may induce long-term synaptic adaptations, which biases social preference toward familiar partners.

Alternatively, OTR can activate multiple G-protein subunits (Gq and Gi) and therefore can activate multiple signaling pathways (Busnelli et al., 2012; Busnelli and Chini, 2018). Signal transduction of OTR homodimer involves Gq pathway activation by phospholipase (PLC) activity and calcium level (Ca2+). Activation of OT neurons can activate OTR expressed in D1 MSNs and consequently enhance D1 MSN activity. It has been found that oxytocin can significantly increase the affinity of D2R binding site with the high-affinity and increase the coupling of D2R to Gi protein, thus inhibiting adenylate cyclase (AC) and consequently reducing the formation of cyclic adenosine phosphate (cAMP; Romero-Fernandez et al., 2013). This may also be the reason why optogenetic activation of OT neurons decreased activities of the D2 MSNs, but increased activities of the D1 MSNs in the present study.

In addition, to explore the direct effect of OT on D1/D2 MSNs in the NAc, we recorded OT-eEPSC at NAc D1/D2 MSN in vitro brain slices. It was found that OT bath administration induced a long-term depression of eEPSCs in NAc D1/D2 MSNs in noncohabitated male mandarin voles, but oxytocin did not induce significant LTD in NAc shell D1/D2 MSNs in individuals with 7 d of cohabitation. Another study revealed that the magnitude of OT-induced LTD is significantly increased in cells from isolated versus socially reared animals (Dölen et al., 2013). Furthermore, oxytocin receptor agonists induced lower eEPSC amplitude in the NAc of sexually naive prairie voles compared with paired prairie voles (Borie et al., 2022). The depression or reduction of eEPSCs in MSNs may inhibit these NAc GABAergic MSNs; subsequently leads to more activation in the VP, showing disinhibiting effect; and increases social motivation of noncohabitated mandarin voles with a stranger of the opposite sex. In contrast, after formation of pair bonding, OT does not effectively inhibit NAc shell GABAergic D1/D2 MSNs but produces more inhibitory effects on the VP and subsequently reduces motivation with an opposite-sex stranger, thus maintaining pair bonding.

Although decreased eEPSC in D2 MSNs after perfusion of OT to the nucleus accumbens of male mandarin voles is consistent with our previous fiber photometry experiment, the NAc shell D2 MSNs showed decreased activity upon optogenetic activation of PVN OT neurons projecting to the NAc shell. However, the decrease in eEPSC amplitude of D1 MSNs in the nucleus accumbens of male mandarin voles after perfusion of OT is not consistent with our result that NAc shell D1 MSNs showed increased activity upon optogenetic activation of PVN OT neurons projecting to the NAc shell. The differential outcomes highlight critical methodological considerations: optogenetic activation of OT neurons may mimic phasic, behaviorally relevant OT release patterns, favoring acute synaptic potentiation through precisely timed pre- and postsynaptic mechanisms (Mikhailova et al., 2016). Bath application of OT in slices may create sustained activation of OT receptors, potentially engaging compensatory mechanisms (e.g., receptor desensitization and secondary messenger cascades) that may oppose acute excitatory effects (Gulliver et al., 2019). To further support this hypothesis, we used whole-cell patch clamp to record the effects of optogenetic activation of OT axonal terminals on D1 MSN activities. We found that optogenetic activation of OT axonal terminals projecting to the NAc shell in vitro brain slice elicited a marked increase in the amplitude of EPSCs in D1 MSNs (Extended Data Fig. S1). This result is consistent with an in vivo experiment that optogenetic activation of PVN OT neurons projecting to the NAc shell increased activity of D1. However, the inconsistency with the effects of OT bath in brain slices on the activity of D1 needs further investigation.

Generally, 3 d of cohabitation does not induce the formation of pair bonding in mandarin voles, but 7 d of cohabitation can (Zhang et al., 2024). In the present study, we found that chemogenetic activation of OTR MSNs in the NAc shell projecting to VP facilitated partner preference after cohabitation of 3 d, whereas chemogenetic inhibition of OTR MSNs in the NAc shell projecting to VP impaired formation of pair bonding after cohabitation of 7 d. This result is contrary to our previous finding that chemogenetic inhibition/activation of VP-projecting D2 MSNs in the NAc promoted/inhibited partner preference formation (Zhang et al., 2024). These differences could be the diversity in valence encoding of the NAc shell MSNs. For example, one recent work found that activation of D2 MSNs in the dorsomedial NAc shell drives preference and increases the motivation for rewards, whereas activation of ventral NAc shell D2 MSNs induces aversion (Yao et al., 2021). A study also showed that optogenetic activation of NAc D1 MSNs or D2 MSNs induces reward or aversion depending on different MSN stimulation protocols (Soares-Cunha et al., 2020). However, this result is consistent with our electrophysiological results showed that the OT-induced LTD on MSNs was weakened after cohabitation, indicating that the enhancement of OTR MSNs in the NAc shell may affect the formation of pair bond. These results are also consistent with a previous study that activation of OTR-Gq signaling in the NAc can promote social approach, suggesting that OTR-Gq in the NAc is necessary to facilitate social interaction (Williams et al., 2020).

The interaction of OTR and the DA system in the NAc may play important roles in regulating social motivation and formation of partner preference (Liu and Wang, 2003). To further clarify the effect of the DA system on OTR MSN function in the formation of pair bonding, we administered D1 receptor antagonist and D2 receptor antagonist after chemogenetic activation of NAc shell OTR MSNs. The result shows that the facilitatory effects of chemogenetic activation of NAc shell OTR MSNs on partner preference were inhibited by D2 receptor antagonist. This is consistent with a previous pharmacological study that D2R antagonists in the nucleus accumbens blocked OT-induced partner preference (Liu and Wang, 2003).

Some limitations should be considered when interpreting our results. First, the effects of OT on social behavior may vary between males and females, which may lead to different results (Gao et al., 2016), but only male subjects were used in the present study, and we should conduct more exploration and research on females in the future. It is also noteworthy that while we strive to accurately discriminate D1/D2 MSNs, we recognize the inherent technical challenge in the precise labeling of dopamine receptor neurons and the possibility of a small fraction of mislabeling (Extended Data Fig. S2). Nonetheless, our study still provides some evidence for the role of interaction of OT and the dopamine systems in regulating the formation of partner preference.

Footnotes

  • This work was supported by STI2030-Major Projects (2022ZD0205101), National Natural Science Foundation of China (32270511; 32270510), Natural Science Basic Research Plan in Shaanxi Province of China (2023-JC-YB-207), and Department of Science and Technology of Shaanxi Province (No. 2022PT-44).

  • ↵*L.Z. and Y.Q. contributed equally to this work.

  • The authors declare no competing financial interests.

  • This paper contains supplemental material available at: https://doi.org/10.1523/JNEUROSCI.2061-24.2025

  • Correspondence should be addressed to Fadao Tai at taifadao{at}snnu.edu.cn or Zhixiong He at hezhixiong{at}snnu.edu.cn.

References

  1. ↵
    1. Aragona BJ,
    2. Liu Y,
    3. Yu YJ,
    4. Curtis JT,
    5. Detwiler JM,
    6. Insel TR,
    7. Wang Z
    (2006) Nucleus accumbens dopamine differentially mediates the formation and maintenance of monogamous pair bonds. Nat Neurosci 9:133–139. https://doi.org/10.1038/nn1613
    OpenUrlCrossRefPubMed
  2. ↵
    1. Borie AM,
    2. Agezo S,
    3. Lunsford P,
    4. Boender AJ,
    5. Guo JD,
    6. Zhu H,
    7. Berman GJ,
    8. Young LJ,
    9. Liu RC
    (2022) Social experience alters oxytocinergic modulation in the nucleus accumbens of female prairie voles. Curr Biol 32:1026–1037.e4. https://doi.org/10.1016/j.cub.2022.01.014 pmid:35108521
    OpenUrlCrossRefPubMed
  3. ↵
    1. Borland JM,
    2. Aiani LM,
    3. Norvelle A,
    4. Grantham KN,
    5. O'Laughlin K,
    6. Terranova JI,
    7. Frantz KJ,
    8. Albers HE
    (2019) Sex-dependent regulation of social reward by oxytocin receptors in the ventral tegmental area. Neuropsychopharmacology 44:785–792. https://doi.org/10.1038/s41386-018-0262-y pmid:30467338
    OpenUrlCrossRefPubMed
  4. ↵
    1. Bosch OJ, et al.
    (2016) Oxytocin in the nucleus accumbens shell reverses CRFR2-evoked passive stress-coping after partner loss in monogamous male prairie voles. Psychoneuroendocrinology 64:66–78. https://doi.org/10.1016/j.psyneuen.2015.11.011 pmid:26615473
    OpenUrlCrossRefPubMed
  5. ↵
    1. Burkett JP,
    2. Andari E,
    3. Johnson ZV,
    4. Curry DC,
    5. de Waal FB,
    6. Young LJ
    (2016) Oxytocin-dependent consolation behavior in rodents. Science 351:375–378. https://doi.org/10.1126/science.aac4785 pmid:26798013
    OpenUrlAbstract/FREE Full Text
  6. ↵
    1. Busnelli M,
    2. Saulière A,
    3. Manning M,
    4. Bouvier M,
    5. Galés C,
    6. Chini B
    (2012) Functional selective oxytocin-derived agonists discriminate between individual G-protein family subtypes. J Biol Chem 287:3617–3629. https://doi.org/10.1074/jbc.M111.277178 pmid:22069312
    OpenUrlAbstract/FREE Full Text
  7. ↵
    1. Busnelli M,
    2. Chini B
    (2018) Molecular basis of oxytocin receptor signalling in the brain: what we know and what we need to know. Curr Top Behav Neurosci 35:3–29. https://doi.org/10.1007/7854_2017_6
    OpenUrlCrossRefPubMed
  8. ↵
    1. Carter CS,
    2. Perkeybile AM
    (2018) The monogamy paradox: what do love and sex have to do with it? Front Ecol Evol 6:202. https://doi.org/10.3389/fevo.2018.00202 pmid:31840025
    OpenUrlCrossRefPubMed
  9. ↵
    1. Carter CS,
    2. DeVries AC,
    3. Getz LL
    (1995) Physiological substrates of mammalian monogamy: the prairie vole model. Neurosci Biobehav Rev 19:303–314. https://doi.org/10.1016/0149-7634(94)00070-H
    OpenUrlCrossRefPubMed
  10. ↵
    1. Carter CS,
    2. DeVries AC,
    3. Taymans SE,
    4. Roberts RL,
    5. Williams JR,
    6. Getz LL
    (1997) Peptides, steroids, and pair bonding. Ann N Y Acad Sci 807:260–272. https://doi.org/10.1111/j.1749-6632.1997.tb51925.x
    OpenUrlCrossRefPubMed
  11. ↵
    1. Cho MM,
    2. DeVries AC,
    3. Williams JR,
    4. Carter CS
    (1999) The effects of oxytocin and vasopressin on partner preferences in male and female prairie voles (Microtus ochrogaster). Behav Neurosci 113:1071–1079. https://doi.org/10.1037/0735-7044.113.5.1071
    OpenUrlCrossRefPubMed
  12. ↵
    1. Dölen G,
    2. Malenka RC
    (2014) The emerging role of nucleus accumbens oxytocin in social cognition. Biol Psychiatry 76:354–355. https://doi.org/10.1016/j.biopsych.2014.06.009
    OpenUrlCrossRefPubMed
  13. ↵
    1. Dölen G,
    2. Darvishzadeh A,
    3. Huang KW,
    4. Malenka RC
    (2013) Social reward requires coordinated activity of nucleus accumbens oxytocin and serotonin. Nature 501:179–184. https://doi.org/10.1038/nature12518 pmid:24025838
    OpenUrlCrossRefPubMed
  14. ↵
    1. Duclot F,
    2. Wang H,
    3. Youssef C,
    4. Liu Y,
    5. Wang Z,
    6. Kabbaj M
    (2016) Trichostatin A (TSA) facilitates formation of partner preference in male prairie voles (Microtus ochrogaster). Horm Behav 81:68–73. https://doi.org/10.1016/j.yhbeh.2016.04.001 pmid:27074037
    OpenUrlCrossRefPubMed
  15. ↵
    1. Gao S, et al.
    (2016) Oxytocin, the peptide that bonds the sexes also divides them. Proc Natl Acad Sci USA 113:7650–7654. https://doi.org/10.1073/pnas.1602620113 pmid:27325780
    OpenUrlAbstract/FREE Full Text
  16. ↵
    1. Gulliver D,
    2. Werry E,
    3. Reekie TA,
    4. Katte TA,
    5. Jorgensen W,
    6. Kassiou M
    (2019) Targeting the oxytocin system: new pharmacotherapeutic approaches. Trends Pharmacol Sci 40:22–37. https://doi.org/10.1016/j.tips.2018.11.001
    OpenUrlCrossRefPubMed
  17. ↵
    1. Insel TR,
    2. Hulihan TJ
    (1995) A gender-specific mechanism for pair bonding: oxytocin and partner preference formation in monogamous voles. Behav Neurosci 109:782–789. https://doi.org/10.1037/0735-7044.109.4.782
    OpenUrlCrossRefPubMed
  18. ↵
    1. Insel TR,
    2. Shapiro LE
    (1992) Oxytocin receptor distribution reflects social organization in monogamous and polygamous voles. Proc Natl Acad Sci U S A 89:5981–5985. https://doi.org/10.1073/pnas.89.13.5981 pmid:1321430
    OpenUrlAbstract/FREE Full Text
  19. ↵
    1. Insel TR,
    2. Winslow JT,
    3. Wang Z,
    4. Young LJ
    (1998) Oxytocin, vasopressin, and the neuroendocrine basis of pair bond formation. Adv Exp Med Biol 449:215–224. https://doi.org/10.1007/978-1-4615-4871-3_28
    OpenUrlCrossRefPubMed
  20. ↵
    1. Johnson ZV,
    2. Walum H,
    3. Jamal YA,
    4. Xiao Y,
    5. Keebaugh AC,
    6. Inoue K,
    7. Young LJ
    (2016) Central oxytocin receptors mediate mating-induced partner preferences and enhance correlated activation across forebrain nuclei in male prairie voles. Horm Behav 79:8–17. https://doi.org/10.1016/j.yhbeh.2015.11.011 pmid:26643557
    OpenUrlCrossRefPubMed
  21. ↵
    1. Keebaugh AC,
    2. Young LJ
    (2011) Increasing oxytocin receptor expression in the nucleus accumbens of pre-pubertal female prairie voles enhances alloparental responsiveness and partner preference formation as adults. Horm Behav 60:498–504. https://doi.org/10.1016/j.yhbeh.2011.07.018 pmid:21851821
    OpenUrlCrossRefPubMed
  22. ↵
    1. Keebaugh AC,
    2. Barrett CE,
    3. Laprairie JL,
    4. Jenkins JJ,
    5. Young LJ
    (2015) RNAi knockdown of oxytocin receptor in the nucleus accumbens inhibits social attachment and parental care in monogamous female prairie voles. Soc Neurosci 10:561–570. https://doi.org/10.1080/17470919.2015.1040893 pmid:25874849
    OpenUrlCrossRefPubMed
  23. ↵
    1. Li LF, et al.
    (2019) Involvement of oxytocin and GABA in consolation behavior elicited by socially defeated individuals in mandarin voles. Psychoneuroendocrinology 103:14–24. https://doi.org/10.1016/j.psyneuen.2018.12.238
    OpenUrlCrossRefPubMed
  24. ↵
    1. Li LF, et al.
    (2020) Reduced consolation behaviors in physically stressed mandarin voles: involvement of oxytocin, dopamine D2, and serotonin 1A receptors within the anterior cingulate cortex. The International Journal of Neuropsychopharmacology 23:511–523. https://doi.org/10.1093/ijnp/pyz060 pmid:31760433
    OpenUrlCrossRefPubMed
  25. ↵
    1. Lim MM,
    2. Murphy AZ,
    3. Young LJ
    (2004) Ventral striatopallidal oxytocin and vasopressin V1a receptors in the monogamous prairie vole (Microtus ochrogaster). J Comp Neurol 468:555–570. https://doi.org/10.1002/cne.10973
    OpenUrlCrossRefPubMed
  26. ↵
    1. Liu Y,
    2. Wang ZX
    (2003) Nucleus accumbens oxytocin and dopamine interact to regulate pair bond formation in female prairie voles. Neuroscience 121:537–544. https://doi.org/10.1016/S0306-4522(03)00555-4
    OpenUrlCrossRefPubMed
  27. ↵
    1. Love TM
    (2014) Oxytocin, motivation and the role of dopamine. Pharmacol Biochem Behav 119:49–60. https://doi.org/10.1016/j.pbb.2013.06.011 pmid:23850525
    OpenUrlCrossRefPubMed
  28. ↵
    1. Marlin BJ,
    2. Mitre M,
    3. D'Amour J A,
    4. Chao MV,
    5. Froemke RC
    (2015) Oxytocin enables maternal behaviour by balancing cortical inhibition. Nature 520:499–504. https://doi.org/10.1038/nature14402 pmid:25874674
    OpenUrlCrossRefPubMed
  29. ↵
    1. Ménard S,
    2. Gelez H,
    3. Girard-Bériault F,
    4. Coria-Avila G,
    5. Pfaus JG
    (2019) Differential role of oxytocin and vasopressin in the conditioned ejaculatory preference of the male rat. Physiol Behav 208:112577. https://doi.org/10.1016/j.physbeh.2019.112577
    OpenUrlCrossRefPubMed
  30. ↵
    1. Mikhailova MA,
    2. Bass CE,
    3. Grinevich VP,
    4. Chappell AM,
    5. Deal AL,
    6. Bonin KD,
    7. Weiner JL,
    8. Gainetdinov RR,
    9. Budygin EA
    (2016) Optogenetically-induced tonic dopamine release from VTA-nucleus accumbens projections inhibits reward consummatory behaviors. Neuroscience 333:54–64. https://doi.org/10.1016/j.neuroscience.2016.07.006 pmid:27421228
    OpenUrlCrossRefPubMed
  31. ↵
    1. Murakami G,
    2. Hunter RG,
    3. Fontaine C,
    4. Ribeiro A,
    5. Pfaff D
    (2011) Relationships among estrogen receptor, oxytocin and vasopressin gene expression and social interaction in male mice. Eur J Neurosci 34:469–477. https://doi.org/10.1111/j.1460-9568.2011.07761.x
    OpenUrlCrossRefPubMed
  32. ↵
    1. Perkeybile AM,
    2. Bales KL
    (2017) Intergenerational transmission of sociality: the role of parents in shaping social behavior in monogamous and non-monogamous species. J Exp Biol 220:114–123. https://doi.org/10.1242/jeb.142182 pmid:28057834
    OpenUrlAbstract/FREE Full Text
  33. ↵
    1. Qu Y, et al.
    (2024) Distinct medial amygdala oxytocin receptor neurons projections respectively control consolation or aggression in male mandarin voles. Nat Commun 15:8139. https://doi.org/10.1038/s41467-024-51652-8 pmid:39289343
    OpenUrlCrossRefPubMed
  34. ↵
    1. Romero-Fernandez W,
    2. Borroto-Escuela DO,
    3. Agnati LF,
    4. Fuxe K
    (2013) Evidence for the existence of dopamine D2-oxytocin receptor heteromers in the ventral and dorsal striatum with facilitatory receptor-receptor interactions. Mol Psychiatry 18:849–850. https://doi.org/10.1038/mp.2012.103
    OpenUrlCrossRefPubMed
  35. ↵
    1. Ross HE,
    2. Freeman SM,
    3. Spiegel LL,
    4. Ren X,
    5. Terwilliger EF,
    6. Young LJ
    (2009a) Variation in oxytocin receptor density in the nucleus accumbens has differential effects on affiliative behaviors in monogamous and polygamous voles. J Neurosci 29:1312–1318. https://doi.org/10.1523/JNEUROSCI.5039-08.2009 pmid:19193878
    OpenUrlAbstract/FREE Full Text
  36. ↵
    1. Ross HE,
    2. Cole CD,
    3. Smith Y,
    4. Neumann ID,
    5. Landgraf R,
    6. Murphy AZ,
    7. Young LJ
    (2009b) Characterization of the oxytocin system regulating affiliative behavior in female prairie voles. Neuroscience 162:892–903. https://doi.org/10.1016/j.neuroscience.2009.05.055 pmid:19482070
    OpenUrlCrossRefPubMed
  37. ↵
    1. Skuse DH,
    2. Gallagher L
    (2009) Dopaminergic-neuropeptide interactions in the social brain. Trends Cogn Sci 13:27–35. https://doi.org/10.1016/j.tics.2008.09.007
    OpenUrlCrossRefPubMed
  38. ↵
    1. Smeltzer MD,
    2. Curtis JT,
    3. Aragona BJ,
    4. Wang Z
    (2006) Dopamine, oxytocin, and vasopressin receptor binding in the medial prefrontal cortex of monogamous and promiscuous voles. Neurosci Lett 394:146–151. https://doi.org/10.1016/j.neulet.2005.10.019
    OpenUrlCrossRefPubMed
  39. ↵
    1. Soares-Cunha C,
    2. de Vasconcelos NAP,
    3. Coimbra B,
    4. Domingues AV,
    5. Silva JM,
    6. Loureiro-Campos E,
    7. Gaspar R,
    8. Sotiropoulos I,
    9. Sousa N,
    10. Rodrigues AJ
    (2020) Nucleus accumbens medium spiny neurons subtypes signal both reward and aversion. Mol Psychiatry 25:3241–3255. https://doi.org/10.1038/s41380-019-0484-3 pmid:31462765
    OpenUrlCrossRefPubMed
  40. ↵
    1. Song Z,
    2. Borland JM,
    3. Larkin TE,
    4. O'Malley M,
    5. Albers HE
    (2016) Activation of oxytocin receptors, but not arginine-vasopressin V1a receptors, in the ventral tegmental area of male Syrian hamsters is essential for the reward-like properties of social interactions. Psychoneuroendocrinology 74:164–172. https://doi.org/10.1016/j.psyneuen.2016.09.001 pmid:27632574
    OpenUrlCrossRefPubMed
  41. ↵
    1. Wang H,
    2. Duclot F,
    3. Liu Y,
    4. Wang Z,
    5. Kabbaj M
    (2013) Histone deacetylase inhibitors facilitate partner preference formation in female prairie voles. Nat Neurosci 16:919–924. https://doi.org/10.1038/nn.3420 pmid:23727821
    OpenUrlCrossRefPubMed
  42. ↵
    1. Williams AV,
    2. Duque-Wilckens N,
    3. Ramos-Maciel S,
    4. Campi KL,
    5. Bhela SK,
    6. Xu CK,
    7. Jackson K,
    8. Chini B,
    9. Pesavento PA,
    10. Trainor BC
    (2020) Social approach and social vigilance are differentially regulated by oxytocin receptors in the nucleus accumbens. Neuropsychopharmacology 45:1423–1430. https://doi.org/10.1038/s41386-020-0657-4 pmid:32198453
    OpenUrlCrossRefPubMed
  43. ↵
    1. Williams JR,
    2. Insel TR,
    3. Harbaugh CR,
    4. Carter CS
    (1994) Oxytocin administered centrally facilitates formation of a partner preference in female prairie voles (Microtus ochrogaster). J Neuroendocrinol 6:247–250. https://doi.org/10.1111/j.1365-2826.1994.tb00579.x
    OpenUrlCrossRefPubMed
  44. ↵
    1. Yao Y,
    2. Gao G,
    3. Liu K,
    4. Shi X,
    5. Cheng M,
    6. Xiong Y,
    7. Song S
    (2021) Projections from D2 neurons in different subregions of nucleus accumbens shell to ventral pallidum play distinct roles in reward and aversion. Neurosci Bull 37:623–640. https://doi.org/10.1007/s12264-021-00632-9 pmid:33548029
    OpenUrlCrossRefPubMed
  45. ↵
    1. Young KA,
    2. Gobrogge KL,
    3. Liu Y,
    4. Wang Z
    (2011) The neurobiology of pair bonding: insights from a socially monogamous rodent. Front Neuroendocrinol 32:53–69. https://doi.org/10.1016/j.yfrne.2010.07.006 pmid:20688099
    OpenUrlCrossRefPubMed
  46. ↵
    1. Young LJ,
    2. Wang Z
    (2004) The neurobiology of pair bonding. Nat Neurosci 7:1048–1054. https://doi.org/10.1038/nn1327
    OpenUrlCrossRefPubMed
  47. ↵
    1. Zhang L, et al.
    (2024) Different roles of D1/D2 medium spiny neurons in the nucleus accumbens in pair bond formation of male mandarin voles. Elife 13:RP100292.
    OpenUrl
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PVN–NAc Shell–VP Circuit OT and OTR Neurons Regulate Pair Bonding via D2R and D1R
Lizi Zhang, Yishan Qu, Lu Li, Yahan Sun, Wei Qian, Jiayu Xiao, Kaizhe Huang, Xiao Han, Haiwei Niu, Luoman Li, Jing Liu, Hui Qiao, Rui Jia, Ting Lian, Zhixiong He, Fadao Tai
Journal of Neuroscience 11 June 2025, 45 (24) e2061242025; DOI: 10.1523/JNEUROSCI.2061-24.2025
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