Zinc enhances GABAergic transmission in rat neocortical neurons

Fuming Zhou, J. J. Hablitz

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

1. Intracellular recordings were made in layer II-III neurons of rat neocortical slices maintained in vitro. The effect of bath application of zinc (50-300 μM) on evoked synaptic activity and passive membrane properties was examined. 2. Excitatory postsynaptic potentials (EPSPs) mediated by N- methyl-D-aspartate (NMDA) and non-NMDA receptors were recorded in response to electrical stimulation. Zinc did not affect either type of EPSP. Resting membrane potential, repetitive firing properties, and input resistance were not altered by zinc. 3. Inhibitory postsynaptic potentials (IPSPs) were enhanced after zinc application. Zinc also induced generation of large amplitude spontaneous γ-aminobutyric acid-(A) (GABA(A))- and GABA(B)- mediated IPSPs. Postsynaptic responses to iontophoretically applied GABA were unaffected. In the presence of zinc, GABAergic synaptic potentials could result in generation of action potentials. 4. Directly evoked IPSPs recorded in the presence of the excitatory amino acid receptor blockers 6-cyano-7- nitroquinoxaline-2,3-dione and 2-amino-5-phosphonovaleric acid were enhanced by zinc. Under these conditions spontaneous IPSPs with superimposed action potentials were present. Baclofen, in the presence of zinc, reduced the amplitude of evoked IPSPs. 5. These results indicate that zinc may be an endogenously occurring neuromodulator. Zinc appears to enhance GABAergic IPSPs by increasing the excitability of inhibitory interneurons, thus resulting in increased GABA release.

Original languageEnglish (US)
Pages (from-to)1264-1269
Number of pages6
JournalJournal of neurophysiology
Volume70
Issue number3
StatePublished - Jan 1 1993

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Zinc
Inhibitory Postsynaptic Potentials
Neurons
gamma-Aminobutyric Acid
Excitatory Postsynaptic Potentials
Action Potentials
Miniature Postsynaptic Potentials
6-Cyano-7-nitroquinoxaline-2,3-dione
2-Amino-5-phosphonovalerate
Aminobutyrates
D-Aspartic Acid
Synaptic Potentials
Baclofen
Glutamate Receptors
Interneurons
N-Methylaspartate
Baths
Membrane Potentials
Electric Stimulation
Neurotransmitter Agents

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Physiology

Cite this

Zinc enhances GABAergic transmission in rat neocortical neurons. / Zhou, Fuming; Hablitz, J. J.

In: Journal of neurophysiology, Vol. 70, No. 3, 01.01.1993, p. 1264-1269.

Research output: Contribution to journalArticle

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