High resolution imaging to study sympathetic nervous system patterning

Authors

• NG Burns
• W Li
• Y Mukouyama

Abstract

In mice, the sympathetic ganglia are formed as early as embryonic day 10.5 (E10.5) and begin to project their axons throughout the body at E13.5 in order to help regulate various biological process in their target organs such as pili muscles in the skin or the muscularis externa in the gut. Sympathetic axons extend along the vasculature in the forelimb skin at E15.5 and begin to innervate the vasculature at E17.5 – E18.5 to help maintain process such as temperature, blood pressure, and oxygen availability. Interestingly, blood vessels are both routes for axon extension as well as sympathetic axon targets for vascular functions. This study seeks to determine if the innervating sympathetic axon comes from the same origin as the nerve bundle that follows along the same vasculature route, or if they come from separate ganglia. With high-resolution whole-mount immunohistochemical analysis along with tissue clearing using an antibody for Tyrosine Hydroxylase (TH) as a sympathetic marker, we are able to map the patterning of the sympathetic nerves in the skin as they develop. Additionally, an inducible TH-CreER mouse line crossed with a Cre-mediated tdTomato reporter line is able to be used to trace single axon projections from the sympathetic ganglia. Currently, our tentative conclusion is that the sympathetic axons branch into the vasculature from the parent axon en route to the pili muscles in the forelimb. We believe this will lead to a better understanding of the interactions between the sympathetic and vascular systems as well as sympathetic nervous system development.

Scientific Focus Area: Developmental Biology

This page was last updated on Friday, March 26, 2021