Abigail Shtekler '21

Mentor: Ms. Kavya Devarakonda

Abstract: The hypothalamus and basal nucleus of the stria terminalis (BNST) regulate stress response and blood glucose levels. Glucose sensing neurons found in the medial amygdala (MeA) led our lab to question what the role of the MeA was in glucose regulation. The lab previously found high levels of cfos, a marker of neuronal activation, in the MeA of mice that were fasted and then refed, but it remained unclear what downstream circuits were involved in feeding behaviors leading to changes in glucose levels. Mice were injected with an adeno-associated virus tagged with GFP into their BNST, and tagged with RFP into their ventromedial hypothalamus (VMH). The viruses were retrograde so that GFP and RFP-tagged neurons in the MeA represented BNST- and VMH-projecting neurons. The mice were weight-matched and put into three groups: one fasted for 36 hours, one fed ad libitum, and one which would undergo a 36-hour fast followed by 1 hour of refeeding time. Once the mice were sacrificed, their brains were extracted and sliced. The tissue was then stained for cfos. Preliminary data from 8 brains showed RFP-positive neurons had the highest overlap with cfos when fasted and the lowest overlap when fed ad libitum. GFP-positive neurons had the highest overlap with cfos when refed and the lowest overlap when fed ad libitum. These results suggest that BNST-projecting MeA neurons are most active with an increase in blood glucose whereas VMH-projecting MeA neurons are most active with a decrease.