The action of botulinum A neurotoxin on the inhibition by antidromic stimulation of the lumbar monosynaptic reflex

Abstract

1. Botulinum toxin type A was injected into gastrocnemius muscles of cats and 2 days later its action on the monosynaptic gastrocnemius reflex and on the recurrent inhibition was investigated. 2. In early local botulism, no significant change in the monosynaptic gastrocnemius reflex was observed. 3. The inhibition by antidromic stimulation of the monosynaptic gastrocnemius reflex was significantly reduced. 4. During the early phases of local botulism an action of botulinum toxin on parts of the soma membrane of the alpha-motoneuron is suggested.

Botulinum toxin A, brain and pain

“…As suggested by some earlier studies, the toxin might penetrate into the central nervous system by axonal transport (Habermann et al, 1974;Wiegand et al, 1976;Wiegand and Wellhöner 1977). To trace the possible spread of BoNT/A into the CNS, the authors employed 125 I-radiolabelled BoNT/A injections into the cat gastrocnemius muscles.…”

Botulinum Toxin and Other New Approaches to Migraine Therapy

“…In earlier animal studies, retrograde transport of the toxin into the CNS was suggested (24). More recently, however, it was shown that only breakdown products of the toxin were transported in a retrograde manner (25).…”

How does botulinum toxin work?

“…One of the most convincing is the effect on the Renshaw cell, since the synaptic input onto it comes from a cholinergic recurrent collateral of the motor axon itself. 6 Such a mechanism has not been demonstrated for certain in humans.…”