Spontaneous activities of SI cortical neurons contribute to the somatotopic reorganization in awake rats

Abstract

In the central nervous system of awake animals, spontaneous activities of neurons participate in multiple functions for learning and performing behavior tasks and in abnormal processings such as epileptic seizure through their synaptic correlations with neighboring neurons. This suggests a possibility that spontaneous activities of SI cortical neurons may contribute to somatotopic reorganization. which is targeted by correlations of neuronal firing among receptive field (RF and boundary neurons. In this study. we investigated changes of spontaneous activities of SI cortical neurons induced by TD in awake rats, and characterized their functional properties correlated with somatosensory plasticity. TD-induced changes of evoked response of RF center (RFC), RF boundary (RFB) and outside (RFO) neurons in SI cortex of an awake rat did show normal plastic changes during TD However， spontaneous activities of all neurons including RFC were gradually facilitated and then recovered to initial value during TD. These results indicate that spontaneous activities of RFC neurons actively compensate the loss of somalosensory inputs from periphery to maintain neural communications with neighboring neurons.