Ca2+ imaging of identifiable neurons labeled by electroporation in insect brains.

Identifiable neurons in the silkmoth brain were studied physiologically after loading of Ca indicator by local electroporation. Small groups of neurons with projections in confined regions of the antennal lobe were labeled, and Ca imaging showed differences in the dose-response characteristics between projection neurons of the macroglomerular complex that responded to different pheromone components. Compared with projection neurons, local interneurons showed shorter response latencies. Targeted labeling of neurons innervating restricted regions of neuropil by local electroporation is a powerful method that will be generally useful for elucidating details of the functional circuitry in insect brains.