[
International C. elegans Meeting,
2001]
C.elegans is a desirable model organism to inquire into the role of chemicals on the nervous system. Numerous chemicals influencing on C.elegans behavior have been studied. On the other hand response to mechanical touch or tap stimuli remains to be described. We are now developing a method to access the role by systematic survey of drugs affecting habituation and its retention. TV camera images of C.elegans behavior under a stereomicroscope are captured to a personal computer by using tapping pulses as tirgger. A future target is to develop the image processing of sequential images. We applied the apparatus to pharmacological screening affecting on tap response, especially habituation and recovery from the habituation by changing ISI, pulse or tap number. We have begun with the method to study actions of various drugs including baclofen, barbital, caffeine, chlorpromazine, chlorzoxazone, diazepam, haloperidol, imipramine, mephenesin, perphenazine, phenobarbital, theophylline and (RS)-CPP. Of these, we found that mephenesin causes rapid habituation but slow recovery from habituation. We are especially interested in the long term habituation. Therefore, in parallel with the work, we are now trying to extend time at the habituated state.