[The long-term potentiation of the late NMDA-dependent components of the responses of the cat motor cortex neurons to stimulation of the direct cortical input of area 5 in the parietal cortex].

Activity of neurons in the motor cortex was recorded in anesthetized cats with glass micropipettes filled with bicuculline solution (bicuculline methiodide, 10 mM in 1 M NaCl). Under these conditions, the minimal (near-threshold) electrical stimulation of the area 5 of the parietal cortex evoked the late neuronal discharges (in 30-200-ms poststimulus interval) in the motor cortex. Such discharges resembled the late NMDA-dependent discharges recorded in the motor cortex of awake cats in response to stimulation of the parietal cortex, which produced the preliminary elaborated conditioned forepaw placing. Under the same conditions, tetanic stimulation of the parietal cortex (100 Hz, 10-20s) led to the long-term potentiation of the late response, which manifested itself as response amplitude augmentation and latency shortening.