Release of dopamine from striatal synaptosomes: high pressure effects.

Adverse neurological manifestations of exposure to high hydrostatic pressure include tremor and convulsions, suggesting an alteration in synaptic transmission, particularly with inhibitory pathways. Because striatal transmission has been implicated in the high pressure neurologic syndrome (HPNS), we investigated the effect of pressure exposure on the release of a major inhibitory neurotransmitter in this region. Synaptosomes isolated from the guinea pig striatum were used to study the effect of compression to 67.7 ATA on [3H]dopamine release. Pressure was found to have a suppressive effect on the initial release of [3H]dopamine by synaptosomes isolated from the striatum of guinea pigs. This finding suggests that decreased inhibitory regulation at the level of the striatum contributes to the hyperexcitability associated with compression to high pressure.