TARGETED EXPRESSION OF TETANUS TOXIN LIGHT-CHAIN IN DROSOPHILA SPECIFICALLY ELIMINATES SYNAPTIC TRANSMISSION AND CAUSES BEHAVIORAL DEFECTS

Tetanus toxin cleaves the synaptic vesicle protein synaptobrevin, and the ensuing loss of neurotransmitter exocytosis has implicated synapto brevin in this process. To further the study of synaptic function in a genetically tractable organism and to generate a tool to disable neur onal communication for behavioural studies, we have expressed a gene e ncoding tetanus toxin light chain in Drosophila. Toxin expression in e mbryonic neurons removes detectable synaptobrevin and eliminates evoke d, but not spontaneous, synaptic vesicle release. No other development al or morphological defects are detected. Correspondingly, only synapt obrevin (n-syb), but not the ubiquitously expressed syb protein, is cl eaved by tetanus toxin in vitro. Targeted expression of toxin can prod uce specific behavioral defects; in one case, the olfactory escape res ponse is reduced.