Abstract
Purpose :
Retinal ganglion cells (RGCs) send direct projections to several sub-regions of the Lateral Hypothalamus (LH) that appear to be conserved in mammals. Our lab has developed a nearly complete typology system for mouse RGC. Here, we aimed to discover what RGC types project to LH and what types of postsynaptic neurons receive retinal input.
Methods :
We used anterograde viral tracing from the retina to quantify the RGC axon density throughout LH. We also inject retrograde virus into LH to label RGCs of interest. RGC types were identified by both light responses and dendritic morphology. To identify the postsynaptic cells in LH receiving RGC input, we performed single-cell patch-clamp electrophysiology in acute brain slices of LH, combined with optogenetically stimulating the optical tract.
Results :
We have confirmed a robust projection from the retina to LH with a particular focus on the Tuberal Nucleus, a region implicated in homeostatic regulation for food consumption. We have successfully labeled individual RGCs in retrograde tracing experiments, and our efforts to assemble a histogram of RGC types in this projection are ongoing.
Conclusions :
A subset of mouse RGCs project to LH. We will present our quantification of this projection, a histogram of RGC types involved, and our progress in characterizing the postsynaptic target cells. These data will inform future studies of the retina’s role in innate behaviors associated with this brain region.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.