Dissecting Neural Circuitries Underlying Responses to Ascarosides

We have shown that coordination of two sensory classes, the general and sex-specific circuitries, is necessary for proper execution of motor responses and social behaviors (Srinivasan et al., 2008b). To understand the role on information processing of these two different sensory classes in social behaviors, we will use the wiring diagram of the worm to identify downstream candidate interneurons. Using laser ablation studies, we will test the hypothesis that both general and sex-specific neurons modulate the same motor command neurons in response to social cues.

Additionally, we seek to answer how sensory integration of different ascarosides occurs within one sensory class. Preliminary data suggests that the male-specific sensory neuron, CEM, is required for sensing two different ascarosides. To understand the functional dynamics of how a single sensory neuron senses different ascarosides, we conducted electrophysiology experiments on this neuron. The results revealed that the CEM neuron shows a variety of responses to different ascarosides. We are currently following up on these results using calcium imaging and optogenetic manipulations to further characterize this male sensory circuit in response.

We intend to extend these methods of investigation to downstream neurons in order to unveil the circuitry of integrated sex and non-sex specific neuron classes.