Membrane properties and synaptic responses of rat striatal neurones in vitro.

Abstract

SUMMARY1. A tissue slice containing a section of striatum was cut obliquely from rat brain so as to preserve adjacent cortex and pallidum. Intracellular recordings were.made from 368 neurones, using either conventional or tight-seal configurations.2. Two types of neurone were distinguished electrophysiologically. Principal cells (96%) had very negative resting potentials (-89 mV) and a low input resistance at the resting membrane potential (39 MQ): membrane conductance (10 nS at -65 mV) increased within tens of milliseconds after the onset of hyperpolarization (99 nS at -120 mV). Secondary cells (4%) had less negative resting potentials (-60 mV) and a higher input resistance (117 MC2 at the resting potential): hyperpolarization caused an inward current to develop over hundreds of milliseconds that had the properties of H-current.3. Most principal cells were activated antidromically by electrical stimulation of the globus pallidus or internal capsule. Intracellular labelling with biocytin showed that principal cells had a medium sized soma (10-18 ptm), extensive dendritic trees densely studded with spines and, in some cases, a main axon which extended towards the globus pallidus.4. Electrical stimulation of the corpus callosum or external capsule evoked a depolarizing postsynaptic potential. This synaptic potential was reversibly blocked by a combination of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 /tM) and DL-2-amino-5-phosphonovaleric acid (APV, 30 #M), but was unaffected by bicuculline (30 ftM) and picrotoxin (100 ,zM). The underlying synaptic current had a fast component (time to peak about 4 ms), the amplitude of which was linearly related to membrane potential and which was blocked by CNQX; in CNQX the synaptic current had a slower component (time to peak about 10 ms) which showed voltage dependence typical of N-methyl-D-aspartate (NMDA) receptors. Both currents reversed at -5 mV.5. Focal electrical stimulation within the striatum (100-300 ,um from the site of intracellular recording) evoked a synaptic potential that was partially blocked (45-95 %) by CNQX and APV: the remaining synaptic potential was blocked by bicuculline (30 ,UM). The bicuculline-sensitive synaptic current reversed at the chloride equilibrium potential.6. The findings confirm that the majority of neostriatal neurones (principal cells, MS 8967 Z.-G. JIANG AND R. A. NORTH medium spiny neurones) project to the pallidum and receive synaptic inputs from cerebral cortex mediated by an excitatory amino acid acting through NMDA and non-NMDA receptors. These cells also receive synaptic inputs from intrinsic striatal neurones mediated by GABA. A minority of cells (4%) have distinct electrophysiological properties, also receive both types of synaptic input, and are presumed to be interneurones.

Cocaine and Amphetamine Depress Striatal GABAergic Synaptic Transmission through D2 Dopamine Receptors

“…Striatal spiny neurons had significantly smaller somata than interneurons (15-25 m vs. 30-60 m) and displayed high resting membrane potential ( Ϫ 82 Ϯ 3 mV), action potential discharge with little adaptation during depolarizing current pulses and, when recorded in voltage-clamp mode, a typical current-voltage relationship ( Figure 1A). These electrophysiological properties were similar to those reported previously by our group and by others for medium spiny neurons of the striatum (Kita et al 1984;Jiang and North 1991;Wilson and Kawaguchi 1996;Calabresi et al 1998).…”

Endogenous Serotonin Excites Striatal Cholinergic Interneurons via the Activation of 5-HT 2C, 5-HT6, and 5-HT7 Serotonin Receptors: Implications for Extrapyramidal Side Effects of Serotonin Reuptake Inhibitors

“…Action potential firing showed strong accomodation and was followed by a long-lasting after hyperpolarization (AHP; 3457108 ms duration) (Figure 1b and c). Hyperpolarizing current pulses evoked a prominent voltage sag, characteristic of an I h current (Figure 1b and d) (Jiang and North, 1991;Kawaguchi, 1993). All neurons included in this study showed these properties.…”

Opposite Membrane Potential Changes Induced by Glucose Deprivation in Striatal Spiny Neurons and in Large Aspiny Interneurons

“…Twenty-nine recorded cells had electrophysiological characteristics different from those described for spiny neurons and showed properties that have been attributed previously to large aspiny interneurons (Wilson et al, 1990;Jiang and North, 1991;Kawaguchi, 1992Kawaguchi, , 1993Kawaguchi et al, 1995). In 11 of these 29 LA interneurons the electrophysiological identification was confirmed by a morphological analysis.…”

“…When the currents were evoked by hyperpolarizing command steps, there was no detectable time-dependent component. Some of these properties have been described previously both in vivo (Preston et al, 1979;Wilson and Groves, 1980;Calabresi et al, 1990c;Onn et al, 1994a;Xu, 1995) and in vitro (Kita et al, 1984;Calabresi et al, 1990bCalabresi et al, , 1991Calabresi et al, , 1995bJiang and North, 1991;Cepeda et al, 1994) and resemble those reported for intracellularly stained spiny striatal neurons (Preston et al, 1979;Cepeda et al, 1994;Onn et al, 1994b;Calabresi et al, 1995a).…”