[Role of raphe nuceli in the development of somatosensory cortex neuronal activity in the kitten].

The formation of background and evoked unit activity in the I somatosensory cortical zone was traced in acute experiments on 5 to 20 days old kittens. Stimulation of anterior (median, dorsal) raphe nuclei inhibits the spike activity of cortical units in kittens beginning with the age of 11 to 12 days and modulates evoked responses. This is manifested in the transformation of immature tonic reactions into phasic, which are inherent in a more definitive type of reaction. The role of the serotoninergic mechanisms in the formation of recurrent inhibition in the cortex is discussed, as well as heterochroneous formation of monoaminergic brain systems in the process of postnatal development.