RT Journal Article
SR Electronic
T1 Characterization of a thalamic nucleus mediating habenula responses to change in illumination
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 047936
DO 10.1101/047936
A1 Ruey-Kuang Cheng
A1 Seetha Krishnan
A1 Qian Lin
A1 Caroline Kibat
A1 Suresh Jesuthasan
YR 2017
UL http://biorxiv.org/content/early/2017/08/02/047936.abstract
AB Background Neural activity in the vertebrate habenula is affected by changes in ambient illumination. The nucleus that links photoreceptors with the habenula is not well characterized. Here, we describe the location, inputs and potential function of this nucleus in larval zebrafish.Results High-speed calcium imaging shows that onset and offset of light evokes a rapid response in the dorsal left neuropil of the habenula, indicating preferential targeting of this neuropil by afferents mediating response to change in irradiance. Injection of a lipophilic dye into this neuropil led to bilateral labeling of a nucleus in the anterior thalamus that responds to onset and offset of light, and that receives innervation from the retina and pineal organ. Lesioning the neuropil of this thalamic nucleus reduced the habenula response to light. Optogenetic stimulation of the thalamus with channelrhodopsin-2 caused depolarization in the habenula, while manipulation with anion channelrhodopsins inhibited habenula response to light and disrupted climbing and diving that is evoked by irradiance change.Conclusions A nucleus in the anterior thalamus of larval zebrafish innervates the dorsal left habenula. This nucleus receives input from the retina and pineal, responds to increase and decrease in irradiance, enables habenula responses to change in irradiance, and may function in light-evoked vertical migration.