(+)-MCPG blocks induction of LTP in CA1 of rat hippocampus via an agonist
action at an mGluR group II receptor..
N.A. BREAKWELL, M.J. ROWAN and R.ANWYL. .
Depts of Physiology and Pharmacology and Therapeutics, Trinity College
Dublin, Dublin 2, Ireland
APStracts 4:303N, 1997.
ABSTRACT
We investigated the effect of mGluR ligands on the induction of long-term
potentiation (LTP) of field EPSPs in CA1 of rat hippocampus, in particular the
manner by which the non-subtype selective metabotropic glutamate receptor
(mGluR) ligand (+)-MCPG blocks LTP induction. Normalised control LTP was
blocked by (+)-MCPG (250 M), but not by the mGluR group I selective antagonist
4-CPG, the mGluR group II selective antagonist MCCG or the mGluR group III
antagonist MAP4. In contrast the mGluR group II agonist (1S,3S)-ACPD (10,
25M) completely and consistently blocked LTP. The block of LTP by both
(1S,3S)-ACPD and (+)-MCPG could be prevented by pre-incubation with the mGluR
group II antagonist MCCG. These studies demonstrate that (+)-MCPG blocks LTP
induction through an agonist action at an mGluR group II receptor and not
through a non-selective antagonist action.
Received 24 June 1997; accepted in final form 28 October 1997.
APS Manuscript Number J528-7.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 14 November 1997