Carbachol-induced rhythmic slow activity (theta) in cat hippocampal formation slices

Application of the cholinergic agonist, carbachol, produced theta-like rhythmical waveforms, recorded in the stratum moleculare of the dentate gyrus in the cat hippocampal formation slices. This effect of carbachol was antagonized by atropine but not d-tubocurarine. These results provide first direct evidence that the hippocampal formation neuronal network in the cat is capable of producing synchronized slow wave activity when isolated from pulsed rhythmic inputs of the medial septum.