Reversibility of microtubule inhibitor-induced transganglionic degenerative atrophy of central terminals of primary nociceptive neurons.

Microtubule inhibitor Vinca alkaloids applied around a peripheral nerve induce transganglionic degenerative atrophy of the central terminals of primary nociceptive neurons. This effect is reversible: 40-50 days later the original histochemical structure of the central terminals is restored. Restoration of fluoride-resistant acid phosphatase activity (the marker enzyme of primary nociceptive neurons) in the Rolando substance is due to regenerative sprouting of the formerly atrophied central terminals. Since peripherally-applied Vinca alkaloids induce transganglionic degenerative atrophy of the central terminals without inducing Wallerian degeneration of the peripheral nerve, and since this effect (virtually a synaptic uncoupling) is only temporary, this approach may be used in the treatment of otherwise intractable neuralgias without inducing irreparable alterations.