ROLE OF 5-HT1B RECEPTOR IN THE PRESSURE-INDUCED BEHAVIORAL AND NEUROCHEMICAL DISORDERS IN RATS

When human divers and experimental animals are exposed to increasing e nvironmental pressure, they develop the high-pressure neurologic syndr ome (HPNS) that has been recently demonstrated to include an increase in striatal dopamine (DA) release. This increase has been correlated w ith enhanced locomotor and motor activity (LMA). In the present study, we investigated the effect of the 5-HT1b receptor antagonist (+/-)cya nopindolol, which has been shown to block at normal pressure the incre ase in striatal DA release induced by the administration of the 5-HT1b receptor agonist CGS 12066B. Our data clearly showed that the adminis tration of (+/-)cyanopindolol partially blocked both the pressure-indu ced increase in striatal DA release and the development of LMA. These results suggest the contribution of the 5-HT neurotransmission in the DA-related neurochemical and behavioral disorders that occur in rats e xposed to high pressure.