High molecular weight microtubule-associated proteins are preferentially associated with dendritic microtubules in brain.

Abstract

The distributions of tubulin and high MW microtubule-associated proteins (HMWP) in rat brain were determined by immunoperoxidase histochemistry with specific antisera. Tubulin was found in microtubules of both neurons and glia and both axons and dendrites. HMWP were found only in neurons where, in all cases examined, they were associated with dendritic microtubules but not those in axons. Both tubulin and HMWP were found in postsynaptic densities. Brain microtubules apparently vary in chemical composition. The preferential association of HMWP with dendritic microtubules suggests that they may play a role in distinguishing between dendritic and axonal export routes from the cell body.