Dual cholinergic and serotonergic excitatory pathways mediate oxygen sensing in the zebrafish gill.

ABSTRACT: The evolution of oxygen sensing included a transition from a diffuse distribution of respiratory chemoreceptors in the gills of water-breathing vertebrates to chemoreceptor clusters confined to the pulmonary epithelium and carotid body in air-breathers. Since the excitatory neurotransmitters mediating oxygen sensing in anamniotes have never been confirmed, the origins of oxygen sensing in vertebrates have remained controversial. In gills isolated from Tg(elavl3:GCaMP6s) zebrafish expressing a genetically encoded reporter of intracellular Ca²⁺ concentration ([Ca²⁺]_i), we demonstrate that acetylcholine (ACh) and nicotine induced a dose-dependent increase in [Ca²⁺]_i in postsynaptic sensory neurons innervating oxygen-chemoreceptive neuroep

SUBMITTER: Reed M 

PROVIDER: S-EPMC12645548 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature