[Postactivation changes in the ultrastructure of motor neurons].

The prolonged high-frequency synaptic activation of the frog spinal motoneurons suppressing their firing, leads to an increase in the size of synapses and to a considerable shift in their ultrastructure. Restoration of the functional and morphological alterations in the cells after cessation of their rhythmical activation proceeds with different speed: the restoration of neurons' ability to generate synaptic and spike potentials in response to testing stimulation of afferents occurs much earlier than the restoration of the cells' ultrastructure and size. Neurons with obviously changed ultrastructure of soma and synaptic apparatus are capable of generating synaptic and spike potentials in response to stimulation. At the same time, the size of the neurons returns to normal either than the normalizing of cell ultrastructures whose speed of restoration varies as well.