The effect of muscimol on hippocampal pyramidal cells.

The effects of muscimol on rabbit hippocampal pyramidal cell firing were studied and compared after iontophoretic, topical, and intravenous administration of the drug. All modes of application resulted in a bicuculline-sensitive, strychnine-insensitive, depression of the monosynaptically activated population spike evoked by micro-stimulation of the contralateral hippocampal field. These findings indicate that systemically administered muscimol selectively activates hippocampal GABA receptors suggesting that this compound may be useful for studying limbic system physiology.