Effects of melanostatine (MIF-1) on focal potentials in slices of rat brain cortex.
The effects of tripeptide melanostatine (Melano-Inhibitory Factor--MIF-1) in concentrations 10(-7)-10(-5) M on parameters of focal potentials (FPs) were studied in slices of rat olfactory and parietal cortex. The addition of MIF-1 to perfusion fluid caused in olfactory cortex the primary depression of FP amplitudes evoked by stimulation of the lateral olfactory tract (LOT); this depression was replaced by restoration and prolonged (30-40 min) enhancement of FP amplitudes and by appearance of additional FP components, such as disynaptic EPSPs and IPSPs. In parietal cortex slices MIF-1 caused the elevation of FP amplitudes evoked by stimulating adjoining points. The repetitive perfusion of slices with MIF-1 potentiated the peptide effect on the increase of FP amplitudes. During excitatory period MIF-1 influenced specifically the functional plasticity in olfactory cortex, having facilitated the induction and sustaining of post-tetanic potentiation (PTP). Data observed support the idea of the activatory influence of MIF-1 on the CNS at the cellular level, which is likely to lie in the ground of antidepressant properties of this peptide.
Mokrushin
A A
AA
I.P. Pavlov Institute of Physiology USSR Academy of Science, Leningrad.
Emelyanov
N A
NA
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D007700:Kinetics; D009075:MSH Release-Inhibiting Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010296:Parietal Lobe / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains
D009075:MSH Release-Inhibiting Hormone