LONG-TERM POTENTIATION WITHIN THE CAT MOTOR CORTEX

SYNAPTIC plasticity in the motor cortex of anesthetized cats was exami ned using intracellular recording and labeling techniques. Intracortic al microstimulation (ICMS) was delivered in the superficial layers and recordings were made from cells in layer V. When the neuron responded to ICMS with an excitatory postsynaptic potential (EPSP), tetanic ICM S (100-200 Hz, 10-20 s) was delivered to the same site. Five of 19 cel ls which were examined and labeled with biocytin showed long-term pote ntiation (LTP) of the EPSP, and 12 cells showed post-tetanic following the tetanic stimulation. All were pyramidal neurons. These results de monstrate that plasticity exists within the intracortical connection o f the motor cortex that may be involved in motor learning.