Possible neutron mechanisms of tactile discrimination in the rat S1 cortex during vibrissa movements

The somatosensory cortex of rats is an important object for investigation of neuron mechanisms of tactile analysis, because there is precise topical representation of vibrissae (barrel subfield) in the S1. Responses of rat barrel field cortex neurons were recorded during vibrissa deflection, voluntary movements of whiskers, and vibrissa movements produced by stimulation of the motor cortex and facial muscles. Experiments showed that there are three groups of neurons in the S1: with responses only during passive vibrissa deflection, only during voluntary movements of vibrissa, and during both passive deflection and voluntary vibrissa movements. Changes in the patterns of responses of the three groups of neurons were revealed during the performance of active vibrissa movements: neurons with short-latency responses, neurons with long latency responses, and neurons with changes in the activity occurred early before the onset of the movements. It is suggested that somatosensory cortical neurons receive peripheral as well as central inputs that modulate their activity