[Reactivity of the cortical neurons to acetylcholine in rats]

Activity of 55 neurons of the sensorimotor cerebral cortex of rats was recorded at iontophoretic application of acetylcholine. 36% of neurons exhibited an excitatory reaction, 30%--inhibitory-excitatory, 18%--inhibitory-excitatory-inhibitory and 16%--excitatory-inhibitory reactions; the type of reaction, in contrast to its expressiveness, did not depend on the the type of reaction, in contrast to its expressiveness, did not depend on the strength of phoresis current. Duration of the excitatory components entering reactions of all neurons formed a continuous series of values in the range of 1.4 to 16 s and had 2 maxima--at the 4-th and 8-th seconds. It is suggested that duration of this component of reaction reflects important functional properties of the nerve cell.