NEUROCHEMICAL CHANGES IN DOPAMINE AND SEROTONIN TURNOVER RATE IN DISCRETE REGIONS OF RAT-BRAIN AFTER THE ADMINISTRATION OF GLYCINERGIC COMPOUNDS

Recent experimental data suggest that glycinergic drugs possessing a c entral action might potentiate the effect of neuroleptics and be usefu l in the treatment of memory disorders and Alzheimer's disease. An act ion of these glycinergic compounds on strychnine insensitive sites, po tentiating the response of N-methyl-D-aspartate receptors, was propose d to explain these effects. However it has also been shown that seroto nin (5-HT) and dopamine (DA) are involved in the mnemonic process and in the pathophysiology of psychosis, respectively. N-palmitoyl glycine (PG), a new glycinergic prodrug, demonstrated nootropic effects and p otentiated the action of neuroleptics. Similar effects were recently o btained with D-cycloserine (DCS). We therefore investigated whether gl ycinergic drug-induced changes in brain 5-HT and DA levels, could be i nvolved in the production of these effects. Wistar rats received PG in doses of 2, 10, 150 mg/kg i.p. An increase in 5-HT turnover in the co rtex of rat brain was observed, a result similar to that seen after DC S administration (5, 50 mg/kg i.p.). A decrease in DA turnover was obs erved in the striatum after DCS treatment. Monoamine function might th erefore be involved in these glycinergic drug-induced effects.