O2-Sensing Neurons Control CO2 Response in C. elegans

摘要: Sensory behaviors are often flexible, allowing animals to generate context-appropriate responses changing environmental conditions. To investigate the neural basis of behavioral flexibility, we examined regulation carbon dioxide (CO2) response in nematode Caenorhabditis elegans. CO2 is a critical sensory cue for many animals, mediating food, conspecifics, predators, and hosts (Scott, 2011; Buehlmann et al., 2012; Chaisson Hallem, 2012). In C. elegans, regulated by polymorphic neuropeptide receptor NPR-1: with N2 allele npr-1 avoid CO2, whereas Hawaiian (HW) or an loss-of-function (lf) mutation appear virtually insensitive (Hallem Sternberg, 2008; McGrath 2009). Here show that ablating oxygen (O2)-sensing URX neurons npr-1(lf) mutants restores avoidance, suggesting NPR-1 enables avoidance inhibiting neurons. was previously shown be activated increases ambient O2 (Persson 2009; Zimmer Busch We find that, mutants, O2-induced activation inhibits avoidance. Moreover, both HW under low conditions, when inactive. Our results demonstrate determined activity O2-sensing suggest O2-dependent likely ecologically relevant mechanism which nematodes navigate gas gradients.