Immunocytochemical evidence for tubulin in the presynaptic terminal of synaptosomes.

Ultrastructural studies of intact tissue rarely show presynaptic microtubules, and immunocytochemical studies on tissue sections have previously been unable to demonstrate tubulin in the nerve terminal. In contrast, a microtubular coil can be readily detected in the presynaptic nerve terminal of synaptosomes. We have developed an immunocytochemical procedure on the synaptosome preparation and demonstrated, using monoclonal antibodies, that in the presynaptic terminal alpha and beta tubulin subunits are specifically restricted to the equatorial microtubular coil.