[Plastic properties of the Purkinje cells of the paramedian lobe of the cerebellum].

The activity of 35 identified Purkinje cells was studied in rabbits in the process of elaboration of motor conditioned reflexes (fore-leg flexion) to clicks. 22 cells exhibited significant conditioned responses: 12 cells -- activation and 10 cells--inhibition ones. The elaboration of activation responses was due mainly (10 cells out of 12) to the excitatory effect of the unconditioned stimulus (electro-cutaneous stimulation) on the cell. The inhibitory responses in the majority of cells (7 out of 10) were elaborated in accordance with their responses to the conditioned stimulus. The Purkinje cells which responded to electro-cutaneous stimulation with "complex" spikes, throughout pairings acquired the ability to respond with the same spikes to the conditioned stimulus. The mechanisms of transformation of the response pattern of Purkinje cells to the conditioned and unconditioned stimuli in the course of the conditioning are discussed.