Effect of GABA muscimol and picrotoxin on electrical activity of the medial preoptic area in unanesthetized rats.

Intracranial cannula along with electrodes was stereotaxically implanted in medial preoptic area of male rats. The electrical activity of mPOA was recorded before and after microinjection of GABA (0.5 micrograms/02 microliters), muscimol (0.5 micrograms/0.2 microliter), picrotoxin (0.25 micrograms/0.2 microliter) and their respective controls. Generalized slowing with an increase in amplitude appeared with GABA and muscimol, while picrotoxin produced just the reverse, i.e. fast activity. Thus the mPOA seems to be vulnerable to GABAergic compounds and supports the diversity of physiological and behavioral functions.