[
International Worm Meeting,
2019]
Animals tune their foraging strategies by using past experience to estimate current resource availability and distribution. Previous studies have reported plasticity in foraging strategies in C. elegans over short time scales over a few hours in response to environmental fluctuations. Genetic variation between different wild isolates are also known to affect foraging decisions, with the lab wild-type N2 strain being the least exploratory and the wild HW CB4856 strain being the most exploratory. We explored whether foraging behavior can be tuned over the time scale of the lifetime of an individual. Stressful environmental conditions like scarcity of food in early larval stages directly affect C. elegans development inducing entry into the dauer developmental arrest phase. We examined adult foraging strategies in post-dauer animals of different genetic backgrounds. Our results show that HW post-dauers have permanently reduced adult foraging behavior, but this long-term plasticity is absent in the lab adapted N2 strain. We also observed changes in the temporal pattern of food search in HW post-dauers, coupled with a high propensity of reversals and turns. We then investigated the neural correlates of this permanent change in behavior, and simultaneously imaged calcium transients in AVA, AIB and RIM which form a local interneuron circuit controlling reversal output. Our results indicate that post-dauer HWs have higher dynamic activity in this circuit in both presence and absence of food cues. We next examined known polymorphisms between the N2 and HW strains to determine the genetic basis of between-strain differences in long-term plasticity. Our work shows that adult foraging behaviour is tuned by developmental experience and involves altering the dynamics of a core navigation circuit, and this plasticity is dependent on the genetic background and life history of the strain.