PHARMACOLOGICAL CHARACTERIZATION OF BOTULINUM TOXIN FOR BASIC SCIENCEAND MEDICINE

The use of Botulinum neurotoxin (BoNT) is increasing in both clinical and basic science. Clinically, intramuscular injection of nanogram qua ntities of BoNT is fast becoming the treatment of choice for a spectru m of disorders including movement disorders such as torticollis, bleph arospasm, Meige Disease, and hemifacial spasm (Borodic er al., 1991, 1 994a; Jankovic and Brin, 1991; Clarke, 1992). Neuroscientists are usin g BoNTs as tools to develop a better understanding of the mechanisms u nderlying the neurotransmitter release process, Consequently, our abil ity to accurately and reliably quantify the biologic activity of botul inum toxin has become more important than ever. The accurate measureme nt of the pharmacologic activity of BoNTs has become somewhat problema tic with the most significant problems occurring with the clinical use of the toxins, The biologic activity of BoNTs has been measured using a variety of techniques including assessment of whole animal response s to in vitro effects on neurotransmitter release. The purpose of this review is to examine the approaches employed to characterize, quantif y and investigate the actions of the BoNTs and to provide a guide to a id investigators in determining which of these methods is most appropr iate for their particular application or use. (C) 1997 Elsevier Scienc e Ltd.