Evidence for mu opiate receptors on inhibitory terminals in area CA1 of rat hippocampus.

Title

Evidence for mu opiate receptors on inhibitory terminals in area CA1 of rat hippocampus.

Creator

Lambert N A; Harrison N L; Teyler T J

Publisher

Neuroscience letters

Date

1991
1991-03

Description

The mechanism of disinhibition produced by opioid peptides was studied using intracellular recording in area CA1 of rat hippocampal slices. The mu-selective opioid peptide [D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin (DAGO) reversibly depressed directly-activated, monosynaptic inhibitory postsynaptic potentials (IPSPs) evoked in the presence of the excitatory amino acid receptor antagonists 6,7-dinitroquinoxaline-2,3-dione (DNQX) and D,L-2-amino-5-phosphonovalerate (APV) in a naloxone-sensitive manner. Depression of monosynaptic inhibitory postsynaptic potentials (IPSPs) by DAGO was not prevented by 1-2 mM Ba2+. DAGO reversibly depressed monosynaptic IPSPs when applied locally close to the recording site, but was ineffective when applied close to the stimulating site in stratum radiatum. These results suggest that DAGO disinhibits pyramidal neurons in area CA1 of the rat hippocampus by activating mu opiate receptors located on the terminals of inhibitory neurons, and by a Ba(2+)-insensitive mechanism.

Subject

Animals; Rats; Action Potentials/drug effects; Quinoxalines/pharmacology; Bicuculline/pharmacology; 2-Amino-5-phosphonovalerate/pharmacology; Ion Channel Gating/drug effects; Barium/pharmacology; Dendrites/chemistry; Enkephalins/metabolism/pharmacology; Hippocampus/*chemistry/ultrastructure; Naloxone/pharmacology; Nerve Endings/chemistry; Potassium Channels/drug effects; Receptors; Enkephalin; Opioid; Ala(2)-MePhe(4)-Gly(5)-; GABA-A/drug effects/physiology; mu; Opioid/*analysis

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

101–104

Issue

1

Volume

124

Citation

Lambert N A; Harrison N L; Teyler T J, “Evidence for mu opiate receptors on inhibitory terminals in area CA1 of rat hippocampus.,” NEOMED Bibliography Database, accessed December 7, 2021, https://neomed.omeka.net/items/show/5502.

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