Intracellular study of rat entopeduncular nucleus neurons in an in vitro slice preparation: electrical membrane properties

We have studied the effects of hypoxia on the membrane properties of striatal neurons intracellularly recorded from a corticostriatal slice preparation. Brief (2–10 min) periods of hypoxia produced reversible membrane depolarizations. Longer periods of hypoxia (12–20 min) produced irreversible membrane depolarizations. In voltage-clamp experiments, hypoxia caused an inward current coupled with an increased membrane conductance. Tetrodotoxin or low calcium (Ca2+)-high magnesium-containing solutions blocked synaptic transmission, but they did not reduce the hypoxia-induced electrical changes. Antagonists of excitatory amino acid (EAA) receptors failed to affect the electrical effects caused by oxygen (O2) deprivation. In low sodium (Na+)-containing solutions the hypoxia-induced inward current was largely reduced. Blockade of ATP-dependent Na+-potassium (K+) pump by ouabain enhanced hypoxia-induced membrane depolarizations and/or inward currents. Our findings indicate that, at least for in vitro experiments, the release of EAAs is not required for the acute hypoxia-induced electrical changes in striatal neurons.

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Active membrane properties of rat neostriatal neurons in an in vitro slice preparation

Experimental Brain Research ◽

10.1007/bf00237018 ◽

1985 ◽

Vol 60 (1) ◽

Cited By ~ 21

Author(s):

H. Kita ◽

T. Kita ◽

S.T. Kitai

Keyword(s):

Membrane Properties ◽

Slice Preparation ◽

Active Membrane

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Dorsal and Ventral Distribution of Excitable and Synaptic Properties of Neurons of the Bed Nucleus of the Stria Terminalis

Journal of Neurophysiology ◽

10.1152/jn.00228.2003 ◽

2003 ◽

Vol 90 (1) ◽

pp. 405-414 ◽

Cited By ~ 41

Author(s):

Regula E. Egli ◽

Danny G. Winder

Keyword(s):

Receptor Antagonist ◽

Drugs Of Abuse ◽

Input Resistance ◽

Membrane Properties ◽

Resting Membrane Potential ◽

Stria Terminalis ◽

Bed Nucleus ◽

Adult Mice ◽

Dependent Potential

The bed nucleus of the stria terminalis (BNST) is a structure uniquely positioned to integrate stress information and regulate both stress and reward systems. Consistent with this arrangement, evidence suggests that the BNST, and in particular the noradrenergic input to this structure, is a key component of affective responses to drugs of abuse. We have utilized an in vitro slice preparation from adult mice to determine synaptic and membrane properties of these cells, focusing on the dorsal and ventral subdivisions of the anterolateral BNST (dBNST and vBNST) because of the differential noradrenergic input to these two regions. We find that while resting membrane potential and input resistance are comparable between these subdivisions, excitable properties, including a low-threshold spike (LTS) likely mediated by T-type calcium channels and an Ih-dependent potential, are differentially distributed. Inhibitory and excitatory postsynaptic potentials (IPSPs and EPSPs, respectively) are readily evoked in both dBNST and vBNST. The fast IPSP is predominantly GABAA-receptor mediated and is partially blocked by the AMPA/kainate-receptor antagonist CNQX. In the presence of the GABAA-receptor antagonist picrotoxin, cells in dBNST but not vBNST are more depolarized and have a higher input resistance, suggesting tonic GABAergic inhibition of these cells. The EPSPs elicited in BNST are monosynaptic, exhibit paired pulse facilitation, and contain both an AMPA- and an N-methyl-d-aspartate (NMDA) receptor-mediated component. These data support the hypothesis that neurons of the dorsal and ventral BNST differentially integrate synaptic input, which is likely of behavioral significance. The data also suggest mechanisms by which information may flow through stress and reward circuits.

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Postnatal Changes in Membrane Properties of Mice Trigeminal Ganglion Neurons

Journal of Neurophysiology ◽

10.1152/jn.2002.87.5.2398 ◽

2002 ◽

Vol 87 (5) ◽

pp. 2398-2407 ◽

Cited By ~ 28

Author(s):

Carmen Cabanes ◽

Mikel López de Armentia ◽

Félix Viana ◽

Carlos Belmonte

Keyword(s):

Postnatal Development ◽

Trigeminal Ganglion ◽

Input Resistance ◽

Membrane Capacitance ◽

Membrane Properties ◽

Inward Rectification ◽

Resting Membrane Potential ◽

Depolarization Rate ◽

Ganglion Neurons

Intracellular recordings from neurons in the mouse trigeminal ganglion (TG) in vitro were used to characterize changes in membrane properties that take place from early postnatal stages (P0–P7) to adulthood (>P21). All neonatal TG neurons had uniformly slow conduction velocities, whereas adult neurons could be separated according to their conduction velocity into Aδ and C neurons. Based on the presence or absence of a marked inflection or hump in the repolarization phase of the action potential (AP), neonatal neurons were divided into S- (slow) and F-type (fast) neurons. Their passive and subthreshold properties (resting membrane potential, input resistance, membrane capacitance, and inward rectification) were nearly identical, but they showed marked differences in AP amplitude, AP overshoot, AP duration, rate of AP depolarization, rate of AP repolarization, and afterhyperpolarization (AHP) duration. Adult TG neurons also segregated into S- and F-type groups. Differences in their mean AP amplitude, AP overshoot, AP duration, rate of AP depolarization, rate of AP repolarization, and AHP duration were also prominent. In addition, axons of 90% of F-type neurons and 60% of S-type neurons became faster conducting in their central and peripheral branch, suggestive of axonal myelination. The proportion of S- and F-type neurons did not vary during postnatal development, suggesting that these phenotypes were established early in development. Membrane properties of both types of TG neurons evolved differently during postnatal development. The nature of many of these changes was linked to the process of myelination. Thus myelination was accompanied by a decrease in AP duration, input resistance ( R in), and increase in membrane capacitance (C). These properties remained constant in unmyelinated neurons (both F- and S-type). In adult TG, all F-type neurons with inward rectification were also fast-conducting Aδ, suggesting that those F-type neurons showing inward rectification at birth will evolve to F-type Aδ neurons with age. The percentage of F-type neurons showing inward rectification also increased with age. Both F- and S-type neurons displayed changes in the sensitivity of the AP to reductions in extracellular Ca2+ or substitution with Co2+ during the process of maturation.

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