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bioRxiv · 10.1101/712091

A novel subtype of pineal projection neurons expressing melanopsin share a common developmental program with classical projection neurons

Sapede, D.·Chaigne, C.·Blader, P.·Cau, E.
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Abstract

The zebrafish pineal organ is a photoreceptive structure containing two main neuronal populations (photoreceptors and projections neurons). Here we describe a new pineal cell type that harbors both characteristics of projection neurons and photoreceptors. Indeed, a subpopulation of projection neurons expresses the melanopsin gene opn4xa suggesting photoreceptive properties. This population of hybrid cell fates, share a similar behaviour regarding dependency for BMP and Notch signalling pathways with classical non-photosensitive projection neurons (PNs) suggesting they are closer to the PN population. We describe two distinct types of activity within PNs: an achromatic LIGHT OFF activity in opn4xa- PNs and a LIGHT ON activity elicited by green and blue light in opn4xa+ PNs. Altogether the discovery and characterization of opn4xa+ PNs suggest a previously unanticipated heterogeneity in the projection neuron population.

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Sapede, D., Chaigne, C., Blader, P., Cau, E.. 2019-07-23. A novel subtype of pineal projection neurons expressing melanopsin share a common developmental program with classical projection neurons. https://doi.org/10.1101/712091

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