Effects of postnatal blockage of cortical activity with tetrodotoxin upon lesion-induced reorganization of vibrissae-related patterns in the somatosensory cortex of rat.

Previous studies have shown that postnatal blockade of thalamocortical activity with either tetrodotoxin (TTX) or the NMDA receptor antagonist DL-2-amino-5-phosphonovalerate (APV) does not prevent the formation of vibrissae-related patterns. In the present study, blockade of cortical activity with TTX was combined with ablation of a row of vibrissae follicles or transection of the infraorbital nerve (ION, the trigeminal nerve branch that supplies the vibrissae follicles) to determine whether the cortical reorganization that follows these lesions in otherwise untreated animals was dependent upon neuronal activity that could be blocked with TTX. The results demonstrated that cortical TTX implants had no quantitative or qualitative effects upon the cortical reorganization that followed either vibrissae follicle cauterization or ION transection.