OVERLAP OF SENSORY REPRESENTATIONS IN RAT BARREL CORTEX AFTER NEONATAL VIBRISSECTOMY

Cortical representation of the common fur of mystacial pad is situated outside postero-medial barrel subfield (PMBSF) in rat primary somatos ensory cortex. Following neonatal vibrissectomy, stimulation of the co mmon fur activates the neurones in PMBSF. We examined if sparing of on e mystacial vibrissa from the neonatal ablation, which results in a ve ry extensive increase of its cortical representation, would prevent th e invasion of the common fur inputs into the PMBSF. The cortical repre sentations were mapped with 2-deoxyglucose (2DG). It was found that si x weeks after neonatal vibrissectomy sparing C3 vibrissa and common fu r inputs were represented in the PMBSF. Their representation shifted f rom its normal location into the barrel field. This effect was observe d in cortical layers II/III, IV and V.