LTP IN CINGULATE CORTEX OF FREELY MOVING RATS - DURATION AND MGLUR INDEPENDENCE

The role of metabotropic glutamate receptors (mGluR) in synaptic trans mission and plasticity of field potentials (fEPs) evoked by subicular stimulation of the cingulate cortex was investigated in freely moving adult rats. Tetanic stimulation with 100 Hz trains caused an enhanceme nt of synaptic transmission in the cingulate cortex which lasted at le ast 24 hours, and can thus, be regarded as long-term potentiation (LTP ). I.c.v. injection of the metabotropic glutamate receptor (mGluR) ant agonist (R,S)-alpha-methyl-4-carboxyphenylglycine (MCPG) did not influ ence either baseline synaptic transmission or LTP of the fEPs. In cont rast to the hippocampus mGluRs of the cingulate cortex seem not to be critically involved in the development of late LTP stages. (C) 1997 Jo hn Wiley & Sons, Ltd.