Dendritic Ca2+ response in cercal sensory interneurons of the cricket Gryllus bimaculatus

In order to understand dendritic information processing, we examined spatio-temporal pattern of intracellular Ca2+ changes in cercal sensory interneurons of the cricket. We used a fluorescent imaging technique with confocal laser-scanning microscopy and a fluorescent calcium indicator, "Calcium Green 1'. Electrical stimulation of cercal sensory nerves induced Ca2+ increase on local dendritic regions in these interneurons. The Ca2+ responses in several dendritic arborizations differed from each other in their amplitude, latency and duration, depending on direction that the cercal nerve was stimulated. These results suggest that synaptic inputs coding directional wind signals are topographically arranged on the dendrite, and that the dynamics of Ca2+ accumulation contribute to integrative processing of the synaptic inputs.