[Retrograde changes in the giant pyramids of the motor area of the isolated cortex]

Retrograde changes in the giant pyramids of the layer V in the motor area of the cortex isolated neuronally at different dates after operation were followed by Nissl method. The cortex isolation was surgically performed by sectioning projection fibres which connect the cortex with subcortical structures after M. M. Hananashvily method (1961). Characteristic retrograde changes appeared in the giant pyramids on the third postoperative day: moderate swelling of cellular bodies, chromatolysis and nuclear displacement towards the periphery. In the following days the retrograde changes progressed rapidly and by the 10th day resulted in a partial destruction of the giant pyramids. One month later in the layer V, only separate cellular shadows were visible; from one month to one year period the giant pyramids in the layer V disappeared completely. Neurons of other layers in this area, as well as small and middle size neurons of the layer V are preserved and show no signs of pathological changes.