[Activity of neurons of the motor-sensory cortex of the cat during natural walking on the rungs of a horizontal ladder].

During locomotion on a flat surface and walking on crosspieces of a horizontal ladder the activity of 56 motor cortex neurons in the cat (5 identified cortico-spinal and 6 cortico-rubral neurons 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 of putting paws right on the support (fulcrum) while walking on the horizontal ladder were as follows: an increase of average activity of 19 neurons by 60 +/- 8% and a decrease of average activity of 19 neurons by 29 +/- 4%; growth of the modulation depth of 41 neurons (5 cortico-spinal and 6 cortico-rubral neurons) on the average by 68 +/- 19% for CS, 34 +/- 18% for CR and 36 +/- 5% for nonidentified neurons; temporary distribution of activity of 88% neurons in the step cycle while walking on the crosspieces of a horizontal ladder was that of walking on the flat surface.