Role of the neural cell adhesion molecule [n-cam] in maintaining the integrity of the neuromuscular junction

ABSTRACT

The present study investigated the role of the neural cell adhesion molecule [N-CAM] in maintaining the integrity of the neuromuscular junction. Immunohistochemical localization of this molecule in muscle tissue of the rat was examined through double immunostaining of longitudinal cryostat sections for synaptophysin [a synaptic vesicle marker] and N-CAM. In addition, immunoelectron microscopy was performed to view the localization of N-CAM at the ultrastructural level. The results showed that N-CAM immunoreactivity at the neuromuscular junction was exclusively restricted to the contact area between the terminal Schwann cells and the nerve terminals. No reaction product could be seen between the pre-and postsynaptic membranes. Such localization of NCAM implies that this molecule is not adequately positioned to play a role in maintaining the integrity of the neuromuscular junction, but rather mediates the axon-Schwann cell interactions