title: Activation and inhibition of tph2 serotonergic neurons operate in tandem to influence larval zebrafish preference for light over darkness.
abstract: Serotonergic neurons have been implicated in a broad range of processes, but the principles underlying their effects remain a puzzle. Here, we ask how these neurons influence the tendency of larval zebrafish to swim in the light and avoid regions of darkness. Pharmacological inhibition of serotonin synthesis reduces dark avoidance, indicating an involvement of this neuromodulator. Calcium imaging of tph2-expressing cells demonstrates that a rostral subset of dorsal raphe serotonergic neurons fire continuously while the animal is in darkness, but are inhibited in the light. Optogenetic manipulation of tph2 neurons by channelrhodopsin or halorhodopsin expression modifies preference, confirming a role for these neurons. In particular, these results suggest that fish prefer swimming in conditions that elicits lower activity in tph2 serotonergic neurons in the rostral raphe.
authors: Neural Circuitry and Behavior Laboratory, Institute of Molecular and Cell Biology, Singapore.
authors: Ruey-Kuang
authors: RK
authors: Cheng
authors: NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore.
authors: Seetha
authors: S
authors: Krishnan
authors: Neural Circuitry and Behavior Laboratory, Institute of Molecular and Cell Biology, Singapore.|Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School, Singapore.|Department of Physiology, National University of Singapore, Singapore.
authors: Suresh
authors: S
authors: Jesuthasan
mesh_terms: D000818:Animals; D002755:Choice Behavior; D003624:Darkness; D065847:Dorsal Raphe Nucleus / Q000378:metabolism / Q000528:radiation effects; D007814:Larva / Q000378:metabolism / Q000528:radiation effects; D008027:Light; D062308:Optogenetics; D059326:Serotonergic Neurons / Q000378:metabolism* / Q000528:radiation effects*; D012701:Serotonin / Q000096:biosynthesis; D015027:Zebrafish / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000378:metabolism*
chemical_list: D029961:Zebrafish Proteins; D012701:Serotonin