The nicotinic acetylcholine receptor Da7 is required for an escape behavior in Drosophila

Acetylcholine is the major excitatory neurotransmitter in the central nervous system of insects. Mutant analysis of the Dα7 nicotinic acetylcholine receptor (nAChR) of Drosophila shows that it is required for the giant fiber-mediated escape behavior. The Dα7 protein is enriched in the dendrites of the giant fiber, and electrophysiological analysis of the giant fiber circuit showed that sensory input to the giant fiber is disrupted, as is transmission at an identified cholinergic synapse between the peripherally synapsing interneuron and the dorsal lateral muscle motor neuron. Moreover, we found that gfA¹, a mutation identified in a screen for giant fiber defects more than twenty years ago, is an allele of Dα7. Therefore, a combination of behavioral, electrophysiological, anatomical, and genetic data indicate an essential role for the Dα7 nAChR in giant fiber-mediated escape in Drosophila. Copyright: