Meeting Abstract
Though C. elegans is a tiny, 1mm, nematode with fewer than 400 neurons in its nervous system, it nevertheless faces the same challenges of finding resources, staying safe, and reproducing that all animals do. Uniquely in C. elegans, it is possible to completely define the neural circuitry that governs the decision-making required for successfully navigating this set of goals. Well-fed C. elegans males will prioritize finding a mate over remaining with a food source and will wander and search around their environment. Wandering away from a food source that lacks mates is stimulated by male-specific sensory neurons in the tail copulatory apparatus, which communicate to the motor system via male-specific interneurons, as well as by signals from the gonad. Male sexual drive, including mate-searching behavior, is stimulated by an oxytocin-related neuropeptide and a PDF (pigment-dispersing factor) neuropeptide. Receptors for these peptides are expressed by multiple neurons throughout the nervous system. Male-specific interneurons in the head dictate associative learning preferences of the male. When a normally attractive cue, salt, is presented together with an aversive cue, starvation, both males and hermaphrodites (females), adults and juveniles, learn to avoid salt. But for sexually-mature males, if mating partners are also present when the two conflicting cues are presented, the sex cue trumps the starvation signal and salt remains attractive. These studies represent just the beginning of a holistic understanding of how drives, environmental cues, and internal physiology are integrated for an individual’s best advantage in the game of survival and reproduction.
