Desensitized states prolong GABAA channel responses to brief agonist pulses

Mathew V. Jones, Gary Westbrook

Research output: Contribution to journalArticle

503 Citations (Scopus)

Abstract

We studied the role of desensitization at inhibitory synapses by comparing nonequilibrium GABAA channel gating with inhibitory postsynaptic currents (IPSCs). Currents activated by brief pulses of 1-10 mM GABA to outside-out patches from cultured hippocampal neurons mimicked GABA-mediated IPSCs. Although the average open time of single GABAA channels following brief pulses was less than 10 ms, channels entered long (τ = 38-69 ms) closed states and subsequently reopened. Movement through these states resulted in paired-pulse desensitization. The time required for deactivation after removal of agonist also increased in proportion to the extent of desensitization. These results suggest that visits to desensitized states buffer the channel in bound conformations and underlie the expression of long-lasting components of the IPSC. Reopening after GABAA receptor desensitization may thus enhance inhibitory synaptic transmission by prolonging the response to a brief synaptic GABA transient.

Original languageEnglish (US)
Pages (from-to)181-191
Number of pages11
JournalNeuron
Volume15
Issue number1
DOIs
StatePublished - 1995

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Inhibitory Postsynaptic Potentials
gamma-Aminobutyric Acid
GABAergic Neurons
GABA-A Receptors
Synaptic Transmission
Synapses
Buffers

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Desensitized states prolong GABAA channel responses to brief agonist pulses. / Jones, Mathew V.; Westbrook, Gary.

In: Neuron, Vol. 15, No. 1, 1995, p. 181-191.

Research output: Contribution to journalArticle

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