INCREASE OF CORTICAL ACETYLCHOLINE-RELEASE AFTER SYSTEMIC ADMINISTRATION OF CHLOROPHENYLPIPERAZINE IN THE RAT - AN IN-VIVO MICRODIALYSIS STUDY

The changes in acetylcholine (ACh) release from the cortex of freely m oving rats after systemic administration of chlorophenylpiperazine (mC PP), a 5-HT2C agonist, were measured utilising microdialysis coupled t o high performance liguid chromatography. mCPP administered intraperit oneally (i.p.) increased cortical ACh release, but failed to do so whe n applied locally in the cortex. The effect of i.p. administered mCPP on cortical ACh release was prevented by i.p. injection of mesulergine , a 5-HT2A/2C receptor antagonist, and isoteoline, a compound previous ly shown to antagonize behavioural effects of mCPP. An increase of cor tical ACh release was also found after the local administration of mCP P in nucleus basalis magnocellularis (NBM). The results of the present work suggest that 5-HT2C receptors located in NBM are involved in the modulation of cortical ACh release in the rat. (C) 1997 Elsevier Scie nce Ireland Ltd.