In natural world, it is necessary that animals can not only respond to various stimuli, but also change the way of response according to context.
The nervous system of C.elegans consists of 302 neurons, and all the synaptic connections were described at EM resolution. Ease of genetic manipulation and the transparent body make it possible to control/monitor activity of specific neurons in vivo with genetically-encoded tools. Despite simplicity, its nervous system generates various behavior including taxis, avoidance and learning. All these characteristics make C.elegans a good model to study multisensory processing in its simple form, at multiple levels from gene to behavior.
We are studying how sensory stimuli affect the nervous system of C.elegans, and how those changes affect sensory processing in other modalities. As input, we use ‘real’ sensory stimuli, and also light-induced direct activation of sensory neurons using channelrhodopsin-2, allowing precise control. To analyze effects of inputs, behavioral quantification and live-imaging with genetically-encoded calcium indicators are used. Preliminary results showed that sensory stimuli can transiently activate the nervous system, and during that period response of worms to other stimuli is promoted. In future we will characterize these changes further in cellular, behavioral and genetic levels.