Changes in the responsive ability of parietal associative cortex neurons to stimulation of associative thalamic nuclei during development of inhibition]

Neuronal responses of area 7 of the parietal associative cortex (PAC) to paired stimulation of the nLD and nLP thalamic nuclei were investigated by extra- and intracellular recording methods. It was found out that testing stimulation of the associative nuclei resulted in inhibition, facilitation or absence of clear neuronal responses. Inhibition was observed more often then other types of reactions. The intracellular recording has shown that inhibition of responses to testing stimuli developed during the initial phase of IPSP, while in the repolarization phase a facilitation was possible. The reversion of a Cl- -dependent component of IPSP did not lead to inhibition of responses to the testing stimulation in that period. It is suggested that inhibition of responses to the testing stimulus occurs in the presence of inward Cl- -dependent current, while facilitation of responses may be a result of activation of the late EPSPs.