[Neurotropic effects of heptapeptide mystixin studied on brain tissue sections].

Neurotropic effects of heptapeptide mystixin have been studied on olfactory cortex neurons in rat brain tissue sections. The application of mystixin onto brain section produced a dose-dependent inhibition of AMPA- and NMDA-receptor-dependent processes. The peptide suppressed the activity of inhibitory processes only at small doses (10, 25, and 50 mg/ml) and potentiated these processes at greater doses (100 and 250 mg/ml). These effects of mystixin are reversible: after washing, the activities of both exciting (except for NMDA-related) and inhibitory mechanisms were restored.