Acute and chronic effects of pentobarbital in relation to postsynaptic GABA receptors: A study with muscimol

Subbiah Sivam, T. Nabeshima, I. K. Ho

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Muscimol, a GABA agonist, enhanced pentobarbital sleeping time in a dose dependent manner. The GABA antagonists such as bicuculline and picrotoxin, and the CNS stimulant such as pentylenetetrazol, inhibited pentobarbital sleeping time; however, all except picrotoxin produced less than 35% maximum inhibition. Picrotoxin, an agent which blocks the chloride ionophore of GABA-receptor complex, exhibited a parallel dose-response curve with respect to muscimol. Chronic administration of pentobarbital by pellet implantation induced tolerance as evidenced by decreased sleeping time; the tolerance receded gradually upon abrupt withdrawal. Muscimol enhanced pentobarbital sleeping time both in tolerant and withdrawal mice. Na+-independent GABA receptor binding, using [3H]muscimol as a ligand, was increased after acute and chronic pentobarbital administration; withdrawal of the pentobarbital reversed the increase in receptor population. None of the treatments altered the affinity of [3H]muscimol binding. These results support the contention that pentobarbital (a) directly acts on the postsynaptic chloride ionophore and (b) augments GABA-mediated postsynaptic effects. The functional significance of the increase in GABA receptor population after pentobarbital treatment is unclear.

Original languageEnglish (US)
Pages (from-to)37-47
Number of pages11
JournalJournal of Neuroscience Research
Volume7
Issue number1
StatePublished - 1982
Externally publishedYes

Fingerprint

Muscimol
Pentobarbital
GABA-A Receptors
Picrotoxin
GABA Receptors
Ionophores
Chlorides
GABA Antagonists
GABA Agonists
Pentylenetetrazole
Bicuculline
gamma-Aminobutyric Acid
Population
Ligands

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Acute and chronic effects of pentobarbital in relation to postsynaptic GABA receptors : A study with muscimol. / Sivam, Subbiah; Nabeshima, T.; Ho, I. K.

In: Journal of Neuroscience Research, Vol. 7, No. 1, 1982, p. 37-47.

Research output: Contribution to journalArticle

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