Taxol stabilizes synaptosomal microtubules without inhibiting acetylcholine release.

Synaptosomes assemble an equatorial coil of microtubules during incubation at 37 degrees C. Stimulation of synaptosomes by veratridine or A23187 for 5 min results in disassembly of the microtubules. The role of microtubule disassembly in neurotransmitter release was investigated using the microtubule-stabilizing drug taxol. Taxol stimulates microtubule assembly in synaptosomes and prevents microtubule disassembly caused by A23187. However, taxol has no effect on the release of [3H]acetylcholine triggered by veratridine or A23187. These results suggest that microtubule turnover is not necessary for neurotransmitter release.