Calcium dynamics regulating the timing of decision-making in C. elegans

• Main Authors: Yuki Tanimoto, Akiko Yamazoe-Umemoto, Kosuke Fujita, Yuya Kawazoe, Yosuke Miyanishi, Shuhei J Yamazaki, Xianfeng Fei, Karl Emanuel Busch, Keiko Gengyo-Ando, Junichi Nakai, Yuichi Iino, Yuishi Iwasaki, Koichi Hashimoto, Koutarou D Kimura
• Format: Article
• Language: English
• Published: eLife Sciences Publications Ltd 2017-05-01
• Series: eLife
• Subjects: calcium imaging; mathematical modeling; olfaction; navigation; molecular genetics; decision-making
• Online Access: https://elifesciences.org/articles/21629

Brains regulate behavioral responses with distinct timings. Here we investigate the cellular and molecular mechanisms underlying the timing of decision-making during olfactory navigation in Caenorhabditis elegans. We find that, based on subtle changes in odor concentrations, the animals appear to choose the appropriate migratory direction from multiple trials as a form of behavioral decision-making. Through optophysiological, mathematical and genetic analyses of neural activity under virtual odor gradients, we further find that odor concentration information is temporally integrated for a decision by a gradual increase in intracellular calcium concentration ([Ca2+]i), which occurs via L-type voltage-gated calcium channels in a pair of olfactory neurons. In contrast, for a reflex-like behavioral response, [Ca2+]i rapidly increases via multiple types of calcium channels in a pair of nociceptive neurons. Thus, the timing of neuronal responses is determined by cell type-dependent involvement of calcium channels, which may serve as a cellular basis for decision-making.