Association of antinociceptive action of botulinum toxin type A with GABA-A receptor.

The mechanism of botulinum toxin type A (BTX-A) antinociceptive action in the central nervous system is little known. The potential interaction between BTX-A and GABAergic system has not been investigated previously. In the present study, we demonstrate prevention of BTX-A antinociceptive effect on formalin-induced inflammatory pain and partial sciatic nerve transection-induced mechanical allodynia by GABA-A antagonist bicuculline, thus suggesting association of the GABA-A receptors and antinociceptive action of BTX-A.