Botulinum toxin in migraine: Role of transport in trigemino-somatic and trigemino-vascular afferents.

摘要: Abstract Migraine secondary to meningeal input is referred extracranial regions innervated by somatic afferents that project homologous in the trigeminal nucleus caudalis (TNC). Reported efficacy of botulinum toxin (BoNT) treating migraine surprising since a local effect BoNT cannot account for its upon input. We hypothesize intradermal acts through central transport afferents. Anesthetized C57Bl/6 mice (male) received unilateral supraorbital (SO) injections BoNT-B (1.5 U/40 μl) or saline. 3 days later, ipsilateral (ipsi)-SO capsaicin (20 μl 0.5 mM solution) (4 μl 0.35 μM). Pre-treatment with ipsi-SO i) decreased nocicsponsive wiping behavior following capsaicin; ii) produced cleavage VAMP V1 region ipsi-TG and TG neurons showing WGA after SO injection; iii) reduced expression c-fos ipsi-TNC iv) activation NK-1 internalization ipsi-meningeal vi) did not label dural conclude taken up peripheral transported terminals where it inhibits transmitter release resulting second order neurons. Further, this study supports hypothesis exerts trans-synaptic action on either neuron (which receives convergent from afferent) terminal/TG converging afferent.