Investigating the Response Time for Mechanosensory Reflexes in Wild Type Caenorhabditis elegans
Soroush Shabani, Jennifer Chen, Henry Ma, Marie Bae, Javier Carmona
Principal Investigator: Dr. Katsushi Arisaka
2018.2 - 2018.6
Abstract. Although several behavioral studies with Caenorhabditis elegans have determined the proportion of responses for tactile stimuli, they have not yet definitively established a consistent time range to consider the reflex as a direct effect of the stimulus. It has been suggested that the sensory neurons for harsh and head stimuli differ, while the interneurons involved in the respective pathways overlap. Specifically, a previous model indicates that the following touch sensory neurons, PVD for harsh touch and ALM for head touch, relay information directly to the same interneuron, AVA, which then fires a signal to the motor neurons. By deducing the time interval of the touch responses and using the accepted rate of 0.25 seconds per neuron fire from previous phototaxis data, we were able to determine whether the previous proposed model was sound. In order to investigate the time of reversal in C. elegans in response to a tactile stimulus, our laboratory utilized wild type (N2) worms plated with both 2% and 1% agar gels. By tracking individual worms with an imaging system, we quantified the range of the average response time for N2 worms. With this data, we were able to establish a time threshold expected as a response for mechanosensory reversal in wild type worms, which can then be utilized for future experiments investigating the proposed neural pathway in C. elegans.