[Activity of neurons of the motor-sensory cortex of the cat during natural locomotion while stepping over obstacles].

During locomotion on flat surface and while walking with stepping over obstacles the activity of 68 motor cortex neurons in cat (there were 12 pyramidal tract neurons (PTN) among them) was modulated in the rhythm of steps, i.e. it increased in one phase of a step and decreased in the other. The results of complication of locomotion task by the necessity to swing of the limbs over obstacles were as follows: an increase of average activity of 34 neurons by 75 +/- 15% and a decrease of the activity of 20 neurons by 30 +/- 4%; growth of modulation depth of 40 neurons (9 PTN) by 35 +/- 5% on the average for non-PTN and by 67 +/- 32% on the average for PTN; temporary distribution of the activity of 81 neurons in the step cycle while walking with stepping over obstacles was that of walking on the flat surface.