Effect of microiontophoretic application of acetylcholine on visual cortical evoked activity to direct cortical stimulation.

Responses of visual cortical neurons (area 17) to direct cortical stimulation of visual areas 18 and 19 were investigated in acute experiments on adult unanesthetized cats, immobilized with diplacin, under local anesthesia, after microiontophoretic application of acetylcholine. Selectivity of the action of acetylcholine on the individual components of the unit responses to direct cortical stimulation was established. The role of acetylcholine as mediator of information in the mechanisms of transcortical interneuronal interaction within the visual system is discussed.