Elsevier

Brain Research

Volume 549, Issue 2, 24 May 1991, Pages 285-291
Brain Research

Intracellular study of rat entopeduncular nucleus neurons in an in vitro slice preparation: response to subthalamic stimulation

https://doi.org/10.1016/0006-8993(91)90469-CGet rights and content

Abstract

Responses of rat entopeduncular nucleus (EP) neurons after stimulation of the subthalamic nucleus (STh) and the morphology of the EP neurons were studied using brain slice preparations. EP neurons were classified into two types based on their electrophysiological properties as reported previously. Of 87 EP neurons, 72 were Type I and the rest were Type II. Synaptic responses to STh stimulation were different in these two cell types. STh stimulation evoked excitatory postsynaptic potentials (EPSPs) followed by strong inhibitory postsynaptic potentials (IPSPs) in Type I neurons and EPSPs without strong IPSPs in Type II neurons. The EPSPs were considered to be monosynaptic because no large change in the latency (1.7 ± 0.5ms) resulted by alteration of stimulus intensity. The EPSPs were reversibly suppressed by kynurenic acid in a dose-dependent manner. Bath application of (+)-tubocurarine (10–50 μM) had no effect on EPSPs or IPSPs. Bath application of bicuculline methiodide (50–100 μM) markedly suppressed IPSPs evoked by STh stimulation and at the same time increased the amplitude and duration of EPSPs without affecting the latency. In the presence of bicuculline methiodide, EPSPs could induce plateau potentials and slow action potentials. Some Type I and Type II neurons were intracellularly labeled by biocytin. Type I neurons were located throughout the EP but Type II neurons were located mainly in the dorsal portion of the EP. Medium sized somata of both Type I and Type II neurons were spine-free and fusiform or round in shape. They had 3–4 thick primary dendrites with diameters of 2–5 μm that branched into thin secondary dendrites. The secondary and tertiary dendrites of Type I neurons were sparsely covered with spines. Dendritic terminals of some Type I neurons had complex arborizations with abundant spines and appendages. The dendrites of Type II neurons were generally smooth and had no complex arborizations at their terminals.

Reference (40)

Cited by (64)

  • Organization of the Globus Pallidus

    2016, Handbook of Behavioral Neuroscience
    Citation Excerpt :

    Habenular projecting axons first join the lenticular fasciculus and then the stria medullaris and form dense terminal fields in the lateral habenular nucleus (Parent et al., 2001). Unlike the GPe, GPi neurons do not emit extensive local axon collaterals (Nakanishi et al., 1991; Parent et al., 2001). It has been shown that GPi-thalamo-cortical projections originating from different territories of GPi, such as the M1 and SMA territories, are largely segregated and innervate different motor areas including M1 and SMA.

  • Functional connectivity and integrative properties of globus pallidus neurons

    2011, Neuroscience
    Citation Excerpt :

    The GPi receives inputs from striatum (Str), GPe, and STN and sends outputs outside the basal ganglia. The GPi neurons do not have extensive local axon collaterals (Nakanishi et al., 1991; Parent et al., 2001), though a few thin collaterals with poor arborization within GPi are sometimes present (Parent and Parent, 2004). Inputs to GPe/GPi can arrive from cerebral cortex via two major distinct pathways, one passing through the Str and the other through the STN.

  • Computational physiology of the neural networks of the primate globus pallidus: Function and dysfunction

    2011, Neuroscience
    Citation Excerpt :

    Nambu and Llinás studied the guinea pig GPe neuron using a brain slice in-vitro preparation. Their type-II neurons resemble the type I reported by the Kita and Kitai group (Kita and Kitai, 1991; Nakanishi et al., 1991). These neurons fired spontaneously at the resting potential level.

  • Subthalamic nucleus evokes similar long lasting glutamatergic excitations in pallidal, entopeduncular and nigral neurons in the basal ganglia slice

    2010, Neuroscience
    Citation Excerpt :

    We ruled out a possible involvement of asynchronous release in the late barrage of STN-evoked EPSCs (Iremonger and Bains, 2007) because the stimulation of STN axons in cut BGS or in slices lacking STN never elicited late transients. Absence of the late component have been also observed in coronal slices of GP (Hanson and Jaeger, 2002), EP (Nakanishi et al., 1991) where STN is absent and in non tilted parasagittal slices of SN (Bradley et al., 2000; Wittmann et al., 2001; Hernandez et al., 2006; Ibanez-Sandoval et al., 2006) that contain only a few STN-SN neurons in their full extent (Beurrier et al., 2006). Under such conditions, STN stimulation evoked only monosynaptic EPSCs or EPSPs that could occasionally trigger an action potential.

  • Organization of the Globus Pallidus

    2010, Handbook of Behavioral Neuroscience
    Citation Excerpt :

    Thus, the somato-dendritic morphology of GPe and GPi neurons are thought to be very similar. However, unlike the GPe, GPi neurons do not emit extensive local axon collaterals (Nakanishi et al., 1991; Parent et al., 2001). The motor-related territories occupy a large area of monkey GPi.

View all citing articles on Scopus
*

Present address: Department of Pharmacology, Faculty of Dentistry, Kyushu University, Fukuoka 812, Japan.

View full text