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bioRxiv · 10.1101/2022.08.07.503074

Optogenetic activation of dorsal raphe serotonin neurons induces a brain-wide response in reward network

Hamada, H. T.·Abe, Y.·Takata, N.·Taira, M.·Tanaka, K. F.·Doya, K.
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Abstract

Serotonin is a neuromodulator that affects multiple behavioral and cognitive functions. Nonetheless, how serotonin causes such a variety of effects via brain-wide projections and various receptors remains unclear. Here we measured brain-wide responses to optogenetic stimulation of serotonin neurons in the dorsal raphe nucleus (DRN) of the male mouse brain using functional MRI with an 11.7T scanner and a cryoprobe. Transient activation of DRN serotonin neurons caused brain-wide activation, including the medial prefrontal cortex, the striatum, and the ventral tegmental area. The same stimulation under anesthesia with isoflurane decreased brain-wide activation, including the hippocampal complex. These brain-wide response patterns can be explained by DRN serotonergic projection topography and serotonin receptor expression profiles, with enhanced weights on 5-HT1 receptors. Together, these results provide insight into the DR serotonergic system, which is consistent with recent discoveries of its functions in adaptive behaviors.

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Hamada, H. T., Abe, Y., Takata, N., Taira, M., Tanaka, K. F., Doya, K.. 2022-08-08. Optogenetic activation of dorsal raphe serotonin neurons induces a brain-wide response in reward network. https://doi.org/10.1101/2022.08.07.503074

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