Subdivisions of the guinea-pig accessory olfactory bulb revealed by the combined method with immunohistochemistry, electrophysiological, and optical recordings

doi:10.1016/S0306-4522(96)00690-2

Neuroscience

Volume 79, Issue 3, 26 May 1997, Pages 871-885

https://doi.org/10.1016/S0306-4522(96)00690-2 Get rights and content

Abstract

The presence of subgroups in vomeronasal sensory neurons has been known in various animals. To elucidate possible functional subdivisions in the guinea-pig accessory olfactory bulb, the combined studies with GTP-binding protein immunohistochemistry, electrophysiological and optical recordings were carried out. Gi2 α and Go α proteins were immunohistochemically localized, respectively, in the anterior and posterior regions of the vomeronasal nerve and glomerular layers, indicating that the guinea-pig accessory olfactory bulb receives at least two different inputs. This suggests that an anatomical boundary exists in these two layers. A mapping study of field potentials in sagittal slice preparations demonstrated that stimulation of the anterior vomeronasal nerve layer elicited field potentials with weak oscillatory responses exclusively in the anterior region of the external plexiform layer, whereas shocks to the posterior vomeronasal nerve layer provoked distinct oscillatory responses within the posterior one. The damping factors of oscillations in the anterior and posterior regions were 0.064±0.028 and 0.025±0.014, respectively. These electrophysiological results suggest that the accessory olfactory bulb consists of two functionally different subdivisions. Real-time optical imaging showed that anterior vomeronasal nerve layer shocks produced neural activity which spread horizontally from anterior to posterior only within the anterior region of the external plexiform and mitral cell layers, whereas shocks to the posterior vomeronasal nerve layer evoked periodic neural activity which spread horizontally from posterior to anterior only within the posterior region. Furthermore, the most posterior extent of the optical response evoked in the anterior region immediately adjoined the most anterior extent of that evoked in the posterior region. The maximal distance of signal propagation in the granule cell layer corresponded to that in the overlying external plexiform and mitral cell layers, indicating that the granule cell layer also has a similar boundary. Thus, these optical imaging studies not only demonstrated a precise boundary in each layer of the accessory olfactory bulb, which was positioned right beneath the boundary defined by GTP-binding protein immunohistochemistry, but also confirmed the observations from electrophysiological mapping that evoked field potentials are independently distributed in each of two subdivisions.

The presence of the functional subdivision in each layer leads us to conclude that the accessory olfactory bulb in the guinea-pig is distinctly segregated into the anterior and posterior subdivisions, and to suggest that there are at least two different input–output pathways in the vomeronasal system.

Section snippets

Immunohistochemistry

Young guinea-pigs (200–300 g, Hartley, Japan SLC, Inc.) were perfused transcardially with 4% paraformaldehyde under deep anaesthesia. The brain was soaked in 20% sucrose in 0.1 M phosphate buffer. Frozen frontal and/or sagittal sections of the AOB were serially cut at 50 μm. After elimination of endogenous peroxidase activity with 0.1% H₂O₂, alternative sections were incubated with antibodies to a synthetic peptide fragment of Gi2 α (Wako Pure Chem. Ind. Ltd, Japan; 1:2 000) or to that of Go α

Results

The AOB is semilunar or semicircular in shape in a sagittal plane and situated on the posterodorsal aspect of the MOB, and its longitudinal length is 1.5–2.0 mm. The AOB has a distinctly laminated structure as shown by a sagittal section with Thionine staining in Fig. 1A.

Two subdivisions revealed by immunohistochemistry

Gi2 α and Go α proteins were immunohistochemically localized, respectively, to the anterior and posterior regions in the VNL/GLL of the guinea-pig AOB, indicating that an anatomical boundary exists in the VNL/GLL. The differential localization of G-proteins was consistent with immunohistochemical studies reported in garter snakes,[32]mice,[4]rats,[52]and opossums.[18]It is intriguing that irrespective of species differences, Gi2 α and Go α proteins are differentially localized in the anterior

Acknowledgements

The authors wish to thank Prof. Genjiro Hirose for encouraging this work. We also thank Mr H. Adachi and Mr S. Muramoto for technical assistance. This work was partially supported by Grants for Project Research, No. P 95-4 from Kanazawa Medical University, and also by a fund of Takasago Corporation.

References (65)

E.D Adrian
The electrical activity of the mammalian olfactory bulb
Electroenceph. clin. Neurophysiol.
(1950)
P.C Barber et al.
An autoradiographic investigation of the projection of the vomeronasal organ to the accessory olfactory bulb in the mouse
Brain Res.
(1974)
J.J Bouyer et al.
Fast fronto-parietal rhythms during combined focused attentive behaviour and immobility in cat: cortical and thalamic localizations
Electroenceph. clin. Neurophysiol.
(1981)
C Dulac et al.
A novel family of genes encoding putative pheromone receptors in mammals
Cell
(1995)
W.J Freeman
Petit mal seizure spikes in olfactory bulb and cortex caused by runaway inhibition after exhaustion of excitation
Brain Res. Rev.
(1986)
M Halpern et al.
Differential localization of G proteins in the opossum vomeronasal system
Brain Res.
(1995)
M Ichikawa et al.
Differential development of binding sites of two lectins in the vomeronasal axons of the rat accessory olfactory bulb
Devl Brain Res.
(1994)
K Imamura et al.
Immunochemical identification of subgroups of vomeronasal nerve fibers and their segregated terminations in the accessory olfactory bulb
Brain Res.
(1985)
H Kaba et al.
Analysis of synaptic events in the mouse accessory olfactory bulb with current source-density techniques
Neuroscience
(1992)
P Litaudon et al.
Origin of the in vivo rat piriform cortex activity recorded with voltage-sensitive dyes: comparison of the optical signals and the field potentials
Brain Res.
(1992)

Y Luo et al.

Identification of chemoattractant receptors and G-proteins in the vomeronasal system of Garter snakes

J. biol. Chem.

(1994)

N.K MacLeod et al.

An electrophysiological study of the accessory olfactory bulb in the rabbit—I. Analysis of electrically evoked potential fields

Neuroscience

(1983)

K Mori

Membrane and synaptic properties of identified neurons in the olfactory bulb

Prog. Neurobiol.

(1987)

K Mori et al.

Projections of two subclasses of vomeronasal nerve fibers to the accessory olfactory bulb in the rabbit

Neuroscience

(1987)

W Reinhardt et al.

An electrophysiological study of the accessory olfactory bulb in the rabbit—II. Input-output relations as assessed from analysis of intra- and extracellular unit recordings

Neuroscience

(1983)

K.J Ressler et al.

Information coding in the olfactory system: evidence for a stereotyped and highly organized epitope map in the olfactory bulb

Cell

(1994)

T.R Saito et al.

Sexual behavior in the female rat following removal of the vomeronasal organ

Physiol. Behav.

(1986)

G.A Schwarting et al.

Subsets of olfactory and vomeronasal sensory epithelial cells and axons revealed by monoclonal antibodies to carbohydrate antigens

Brain Res.

(1991)

G.A Schwarting et al.

A unique neuronal glycolipid defines rostrocaudal compartmentalization in the accessory olfactory system of rats

Devl Brain Res.

(1994)

T Sugai et al.

Damped oscillatory activity in the guinea-pig accessory olfactory bulb slice

Neurosci. Lett.

(1995)

M Sugitani et al.

Optical imaging of the in vitro guinea-pig piriform cortex activity using a voltage-sensitive dye

Neurosci. Lett.

(1994)

M Sugitani et al.

Signal propagation from piriform cortex to the endopiriform nucleus in vitro revealed by optical imaging

Neurosci. Lett.

(1994)

S Takami et al.

The differential staining patterns of two lectins in the accessory olfactory bulb of the rat

Brain Res.

(1992)

K Taniguchi et al.

Subdivisions of the accessory olfactory bulb, as demonstrated by lectin histochemistry in the golden hamster

Neurosci. Lett.

(1993)

T Van Groen et al.

Electrophysiological mapping of the accessory olfactory bulb of the rabbit (Oryctolagus cuniculus)

Expl Neurol.

(1986)

R Vassar et al.

Spatial segregation of odorant receptor expression in the mammalian olfactory epithelium

Cell

(1993)

C.J Wysocki

Neurobehavioral evidence for the involvement of the vomeronasal system in mammalian reproduction

Neurosci. Biobehav. Rev.

(1979)

A.C Allison

The structure of the olfactory bulb and its relationship to the olfactory pathways in the rabbit and the rat

J. comp. Neurol.

(1953)

A Berghard et al.

Sensory transduction in vomeronasal neurons: evidence for G α o, G α i2, and adenylyl cyclase Π as major components of pheromone signaling cascade

J. Neurosci.

(1996)

Cajal S. Ramon y. (1955) Studies on the Cerebral Cortex. Lloyd-Luke Medical Books,...

A.R Cinelli et al.

Voltage-sensitive dyes and functional activity in the olfactory pathway

A. Rev. Neurosci.

(1992)

A.R Cinelli et al.

Salamander olfactory bulb neuronal activity observed by video rate, voltage-sensitive dye imaging. II. Spatial and temporal properties of responses evoked by electric stimulation

J. Neurophysiol.

(1995)

Cited by (60)

Oxytocin facilitates the induction of long-term potentiation in the accessory olfactory bulb
2008, Neuroscience Letters
When female mice are mated, they form a memory to the pheromonal signal of their male partner. Several lines of evidence indicate that the neural changes underlying this memory occur in the accessory olfactory bulb (AOB) at the first stage of the vomeronasal system. The formation of this memory depends on the mating-induced release of noradrenaline in the AOB. In addition to noradrenaline, the neuropeptide oxytocin (OT) is also released within the central nervous system during mating. Because OT has been implicated in social memory and its receptors are expressed in the AOB, we hypothesized that OT might promote the strength of synaptic transmission from mitral to granule cells in the AOB. To test this hypothesis, we analyzed the lateral olfactory tract-evoked field potential that represents the granule cell response to mitral cell activation and its plasticity in parasagittal slices of the AOB. Of the 10-, 20-, 50-, and 100-Hz stimulations tested, the 100-Hz stimulation was optimal for inducing long-term potentiation (LTP). OT paired with 100-Hz stimulation that only produced short-term potentiation enhanced LTP induction in a dose-dependent manner. OT-paired LTP was blocked by both the selective OT antagonist desGly-NH₂,d(CH₂)₅[Tyr(Me)²,Thr⁴]-ornithine vasotocin and the N-methyl-d-aspartate (NMDA) receptor antagonist dl-2-amino-5-phosphonovaleric acid. These results indicate that OT can function as a gate to modulate the establishment of NMDA receptor-dependent LTP at the mitral-to-granule cell synapse in the AOB.
Conditional genetic labeling of mitral cells of the mouse accessory olfactory bulb to visualize the organization of their apical dendritic tufts
2008, Molecular and Cellular Neuroscience
Chemical information captured through the vomeronasal sensory neurons is transmitted to mitral cells in the accessory olfactory bulb (AOB). Morphological characterization of AOB mitral cells is crucial to reveal the mechanisms underlying pheromone and other chemical information processing. Here, we developed a conditional genetic approach to visualize single AOB mitral cells in mice and analyzed the distribution of their apical dendritic tufts and cell bodies. We found that there is a subpopulation of superficial AOB mitral cells with small cell bodies and simple dendritic arborization. We also showed that segregation of the anterior and posterior AOB appears incomplete at the level of the mitral cell positions. Furthermore, we demonstrated that significant population of the anterior AOB mitral cells has multiple apical dendritic tufts organized in a quite small range along the dorsal–ventral axis. These findings have important implications in how various chemical signals may be processed in the AOB.
Effects of N-methyl-D-aspartate glutamate receptor antagonists on oscillatory signal propagation in the guinea-pig accessory olfactory bulb slice: Characterization by optical, field potential and patch clamp recordings
2005, Neuroscience
To characterize the role of N-methyl-d-aspartate glutamate receptors in oscillations induced by a single electrical stimulation of the vomeronasal nerve layer, optical, field potential and patch clamp recordings were carried out in guinea-pig accessory olfactory bulb slice preparations. Bath application of the N-methyl-d-aspartate receptor antagonists, 2-amino-5-phosphonovaleric acid or MK-801, produced an increase in frequency of oscillating waves (oscillation) in external plexiform and mitral cell layers. The removal of Mg²⁺ from perfusate abolished oscillations, while subsequent application of 2-amino-5-phosphonovaleric acid or MK-801 restored oscillations. Vomeronasal nerve layer-evoked postsynaptic currents were analyzed by whole-cell clamp recordings from mitral and granule cells. A long-lasting excitatory postsynaptic current and periodic inhibitory postsynaptic currents, which were superimposed on the long excitatory postsynaptic current, were observed in mitral cells. The frequency of the periodic inhibitory postsynaptic currents correlated with the frequency of oscillations observed in the optical and field potential recordings. Furthermore, periodic inhibitory postsynaptic currents were blocked by puff application of bicuculline to the external plexiform layer/mitral cell layer, where mitral cells make dendrodendritic synapses with granule cells. In addition, puff application of the non-N-methyl-d-aspartate antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, to the external plexiform layer/mitral cell layer suppressed an early phase of periodic inhibitory postsynaptic currents (membrane oscillation), whereas 2-amino-5-phosphonovaleric acid suppressed the late phase of periodic inhibitory postsynaptic currents. These data indicate that periodic excitatory postsynaptic currents of granule cells induce relevantly periodic inhibitory postsynaptic currents in mitral cells via dendrodendritic synapses and suggest that feedback inhibition regulates generation of oscillation via activation of non-N-methyl-d-aspartate glutamate receptors and gradual attenuation of oscillation via activation of N-methyl-d-aspartate receptors on granule cells.
Developmental changes in oscillatory and slow responses of the rat accessory olfactory bulb
2005, Neuroscience
Citation Excerpt :
P4–P28 and adult (P80) rats were used for experiments. Experiments were conducted as previously described (Sugai et al., 1997, 1999, 2000). Briefly, after decapitation of rats, the olfactory bulb was removed as quickly as possible and placed in cold (2°C), oxygenated (95% O2/5% CO2) sucrose-based artificial cerebrospinal fluid (sucrose-ACSF) containing (in mM): 191 sucrose, 5 KCl, 1.24 KH2PO4, 1.3 MgSO4, 2.4 CaCl2, 26 NaHCO3, and 10 glucose.
Field potential, patch-clamp and optical recordings were performed in accessory olfactory bulb slices of postnatal rats following single electrical stimulation of the vomeronasal nerve layer. On the basis of differences in the components of the field potential, postnatal days were divided into three periods: immature (until postnatal day 11), transitional (postnatal days P12-17) and mature periods (after postnatal day 18). During the immature period, vomeronasal nerve layer stimulation provoked a characteristic damped oscillatory field potential, and the field potential recorded in the glomerular layer consisted of a compound action potential followed by several periodic negative peaks superimposed on slow components. Reduction in [Mg²⁺] enhanced slow components but did not affect oscillation, whereas an NMDA receptor antagonist, d-2-amino-5-phosphonovalerate, depressed slow components but did not affect the oscillation. During the mature period, slow components and the periodic waves (oscillation) disappeared. The time course of the field potential was similar to that in adults, suggesting that the accessory olfactory bulb reached electrophysiologically maturity at postnatal day 18. A non-NMDA receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, inhibited vomeronasal nerve layer-induced responses, while d-2-amino-5-phosphonovalerate had no effect, suggesting that NMDA and non-NMDA receptors are active in immature tissues, whereas non-NMDA receptors predominated in mature tissue. Results from whole-cell patch recordings in mitral and granule cells yielded results consistent with those from field potential and optical recordings. Further, a gradual decrease in number and frequency of oscillating waves was observed until postnatal day 17. Analyses of the depth profile of field potentials and current source density in immature tissue suggested that the oscillation and slow components originated in the glomerular layer but not in the external plexiform/mitral cell layer. Further, a new type of oscillation, which was independent of the reciprocal dendrodendritic synapses between mitral and granule cells, was detected. These data indicate that the lack of oscillatory suppression by immature NMDA receptors may play a critical role in the dynamic alteration of bulbar conditions.
To-and-fro optical voltage signal propagation between the insular gustatory and parietal oral somatosensory areas in rat cortex slices
2004, Brain Research
Taste perception depends not only on special taste information processed in the insular cortex, but also on oral somesthetic processing in the parietal cortex. Many insular cortex neurons show multimodal responsiveness. Such multimodality may be enabled by signal exchange between these two cortices. By using the protocol that we have developed, a synchronized population oscillation of synaptic potentials was induced in the parietal cortex by stimulation to the insular cortex in rat neocortex slices. The spatiotemporal pattern of propagation of this oscillation was studied by recording voltage-sensitive optical signals and field potentials. The first wavelet of the oscillation was propagated from the insular stimulation site to the parietal cortex. However, the second and later wavelets propagated back from the parietal cortex to the insular cortex. The oscillation was detected in the insular cortex as well, but was actually generated in the parietal cortex. Thus, the initial peak of optical signal, sent from the insular to parietal cortex, served to generate oscillatory responses in the parietal cortex, which propagated back to the insular cortex wave-by-wave. We propose that this to-and-fro propagation may be an artificially exaggerated demonstration of an intrinsic mechanism relevant to signal exchange between the parietal and insular cortices.
Age-dependent emergence of a parieto-insular corticocortical signal flow in developing rats
2004, Developmental Brain Research
Citation Excerpt :
In some experiments, we used high-speed optical recording with a voltage-sensitive dye (NK2761, 0.125 mg/ml; Nihon Kanko, Okayama, Japan) to observe spatiotemporal dynamics of spreading neural activities. The details of optical recording system used in this study have been described in our previous reports [15,24]. The slices were placed in a submerged-type chamber set on the stage of an upright microscope (Olympus IMT-2) and perfused with medium (30 °C) at 5 ml/min.
By using the procedure that we developed for inducing population oscillation, it was previously demonstrated that insular cortex stimulation can evoke insulo-parietal field potential propagation and synchronized population oscillation in the parietal cortex in slices obtained from mature rats (27–35 days old). By using the same procedure, we have now studied the reciprocal parieto-insular projection. Parietal cortex stimulation elicited synchronized population oscillation in the parietal—but not insular—cortex in mature tissues. In the insular cortex, the initial wavelet of the oscillation generated by parietal cortex stimulation propagated, but the entire oscillation did not. A prior induction—but not simultaneous occurrence—of oscillation in the parietal cortex sufficed to have this initial wavelet propagate. In immature tissue (9–10 days old), both the parietal cortex oscillation and the parieto-insular propagation were induced only with low [Mg²⁺]_o. This age dependence is exactly the same as we previously observed for the reciprocal insulo-parietal propagation. Given that the parietal cortex receives somatosensory inputs from the oral cavity and the insular cortex receives primarily chemosensory inputs from the same source, the age-dependent changes in the availability of bidirectional signal traffic between these cortices might contribute to the development of multimodal responsiveness of taste neurons.

View all citing articles on Scopus

View full text

Subdivisions of the guinea-pig accessory olfactory bulb revealed by the combined method with immunohistochemistry, electrophysiological, and optical recordings

Abstract

Section snippets

Immunohistochemistry

Results

Two subdivisions revealed by immunohistochemistry

Acknowledgements

Electroenceph. clin. Neurophysiol.

Brain Res.

Electroenceph. clin. Neurophysiol.

Cell

Brain Res. Rev.

Brain Res.

Devl Brain Res.

Brain Res.

Neuroscience

Brain Res.

J. biol. Chem.

Neuroscience

Prog. Neurobiol.

Neuroscience

Neuroscience

Cell

Physiol. Behav.

Brain Res.

Devl Brain Res.

Neurosci. Lett.

Neurosci. Lett.

Neurosci. Lett.

Brain Res.

Neurosci. Lett.

Expl Neurol.

Cell

Neurosci. Biobehav. Rev.

The structure of the olfactory bulb and its relationship to the olfactory pathways in the rabbit and the rat

J. comp. Neurol.

Sensory transduction in vomeronasal neurons: evidence for G α o, G α i2, and adenylyl cyclase Π as major components of pheromone signaling cascade

J. Neurosci.

Voltage-sensitive dyes and functional activity in the olfactory pathway

A. Rev. Neurosci.

Salamander olfactory bulb neuronal activity observed by video rate, voltage-sensitive dye imaging. II. Spatial and temporal properties of responses evoked by electric stimulation

J. Neurophysiol.