Long-latency responses to conditioned stimulus in the cat motor cortex can be generated through the enhancement of efficiency excitatory collaterals of pyramidal neuron

The long-latency excitatory components are the characteristic feature of neuronal responses to conditional stimuli in the motor cortex of the cat. The data presented suggest that the neuronal machine that generates these reactions is that, generating long-latency epileptiform discharges in epileptogenic cortex. The long-latency component generation is based on NMDA-receptor activation in the recurrent excitatory collaterals of the cortical pyramidal neurons. The response delay is dependent on initial activation of inhibitory GABA(A) receptors. The emergence of the late components in the course of motor learning take place as a result of efficiency enhancement of recurrent collaterals synaptic linkage with pyramidal neurons.