CROSS-TALK BETWEEN 5-HT <sub>1A</sub> AND 5-HT <sub>7</sub> RECEPTORS: ROLE IN THE AUTOREGULATION OF THE BRAIN SEROTONIN SYSTEM AND IN MECHANISM OF ANTIDEPRESSANTS ACTION
Recent studies considerably extended our knowledge of the mechanisms and physiological role of the interaction between different receptors in the brain. Current review summarizes data on the formation of receptor complexes and the role of such complexes in the autoregulation of the brain serotonin system, behavioral abnormalities and mechanism of antidepressants action. Particular attention is paid to 5-HT <sub>1A</sub> and 5-HT <sub>7</sub> receptor heterodimers. The results described in the present review indicate that: i) dimerization and formation of mobile receptor complexes is a common feature for the members of G-protein coupled receptor superfamily; ii) 5-HT <sub>7</sub> receptor appears to be a modulator for 5-HT <sub>1A</sub> receptor - the key autoregulator of the brain serotonin system; iii) 5-HT <sub>1A</sub>/5-HT <sub>7</sub> receptor complexes formation is one of the mechanisms for inactivation and desensitization of the 5-HT <sub>1A</sub> receptors in the brain; iv) differences in the 5-HT <sub>7</sub> receptor and 5-НТ <sub>1A</sub>/5-НТ <sub>7</sub> heterodimers density define different sensitivity of pre- and postsynaptic 5-HT <sub>1A</sub> receptors to chronic treatment with selective serotonin reuptake inhibitors.