Environmental CO2 inhibits Caenorhabditis elegans egg-laying by modulating olfactory neurons and evokes widespread changes in neural activity.

摘要: Carbon dioxide (CO2) gradients are ubiquitous and provide animals with information about their environment, such as the potential presence of prey or predators. The nematode Caenorhabditis elegans avoids elevated CO2, previous work identified three neuron pairs called "BAG," "AFD," "ASE" that respond to CO2 stimuli. Using in vivo Ca(2+) imaging behavioral analysis, we show C. can detect independently these sensory pathways. Many neurons examined, including AWC olfactory neurons, ASJ ASK gustatory ASH ADL nociceptors, a rise Ca(2+). In contrast, glial sheath cells harboring endings elegans' major chemosensory exhibit strong sustained decreases response high CO2. Some responses appear be cell intrinsic. Worms therefore may couple detection other cues at earliest stages processing. We persistently suppresses oviposition Hermaphrodite-specific (HSNs), executive driving egg-laying, tonically inhibited when is elevated. modulates egg-laying system partly through neurons: High activates by cGMP-dependent mechanism, output inhibits HSNs. Our shows more complex cue for than previously thought, both terms behavior neural circuitry.