1. Zebrafish Dark‐Dependent Behavior Requires Phototransduction by the Pineal Gland.
- Author
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Wexler, Yair, Huang, Dengfeng, Medvetzky, Adar, Armbruster, Daniel, Driever, Wolfgang, Yan, Jun, and Gothilf, Yoav
- Abstract
Located dorsally underneath a thin translucent skull in many teleosts, the pineal gland is a photoreceptive organ known as a key element of the circadian clock system. Nevertheless, the presence of additional routes of photoreception presents a challenge in determining its specific roles in regulating photic‐related behavior. Here, we show the importance of the pineal gland in mediating a prolonged motor response of zebrafish larvae to sudden darkness, both as a photodetector and as a circadian pacemaker. This was evident by a reduced motor response of Bsx‐deficient larvae, lacking a pineal gland, to sudden darkness. Moreover, the typical daily rhythm of the intensity of this response was lost in the pineal‐less larvae. In contrast, motor response to a sudden increase in illumination was unaffected. Furthermore, we show that the pineal‐mediated behavioral response to darkness requires two elements: the photoreceptor cells and the projecting neurons. Dark response was impaired in larvae whose pineal photoreceptor cells were genetically ablated and in larvae whose pineal projecting neurons had undergone laser‐axotomy. This study thus establishes the pineal gland as a mediator of dark‐dependent behavior and reveals underlying cellular components involved in transducing information about darkness to the brain. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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