NEONATAL INFRAORBITAL NERVE TRANSECTION AND BLOCKADE OF AXOPLASMIC-TRANSPORT REDUCE EXPRESSION OF ACETYLCHOLINESTERASE BY THALAMOCORTICAL AXONS

Acetylcholinesterase (AChE) is transiently expressed by ventrobasal th alamic neurons and their axons in the primary somatosensory cortex and this enzyme has been used as a marker for these axons in studies conc erned with cortical development and plasticity. The present experiment evaluated the effects of both peripheral nerve transection and blocka de of axoplasmic transport upon the expression of AChE in thalamic axo n terminals in the primary somatosensory cortex. Both manipulations re sulted in marked reductions in the density of AChE in thalamocortical axons and less dramatic decreases in the density of this enzyme in tha lamic neurons. These results indicate that AChE may not invariably pro vide unequivocal information about the distribution of somatosensory t halamocortical axon terminals in developing rodents.