BEHAVIORAL AND NEUROCHEMICAL ACTIONS OF THE STRYCHNINE-INSENSITIVE GLYCINE RECEPTOR ANTAGONIST, 7-CHLOROKYNURENATE, IN RATS

The present study investigated if blockade of the modulatory glycine r eceptor of the NMDA receptor complex influences the expression of beha vior (sniffing stereotypy and locomotion) and dopamine metabolism in r ats as it has been shown for NMDA receptor antagonists. The glycine re ceptor antagonist, 7-chlorokynurenate (7-chloro-4-hydroxyquinoline-2-c arboxylic acid), induced a dose-dependent sniffing stereotypy but had no effect on locomotion when it was given i.c.v. The glycine receptor agonist, D-cycloserine (D-4-amino-3-isoxazolidinone), antagonized the sniffing stereotypy. 7-Chlorokynurenate had no influence on dopamine m etabolism in the striatum and the nucleus accumbens, but moderately de creased the metabolism in the prefontal cortex. Comparison of behavior al and neurochemical outcomes suggests that the failure to induce loco motion correlates with the unchanged dopamine metabolism in the basal ganglia, while sniffing stereotypy does not. These result show that bl ockade of the glycine receptor of the NMDA receptor complex induces a behavioral and neurochemical profile similar to that of competitive NM DA receptor antagonists.