EFFECTS OF POSTNATAL BLOCKADE 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 antagoni st DL-2-amino-5-phosphonovalerate (APV) does not prevent the formation of vibrissae-related patterns. In the present study, blockade of cort ical activity with TTX was combined with ablation of a row of vibrissa e follicles or transection of the infraorbital nerve (ION, the trigemi nal nerve branch that supplies the vibrissae follicles) to determine w hether the cortical reorganization that follows these lesions in other wise untreated animals was dependent upon neuronal activity that could be blocked with TTX. The results demonstrated that cortical TTX impla nts had no quantitative or qualitative effects upon the cortical reorg anization that followed either vibrissae follicle cauterization or ION transection.