Date of Defense


Date of Graduation



Biological Sciences

First Advisor

John Spitsbergen

Second Advisor

Monica McCullough

Third Advisor

Alberto Cintron-Colon


Hypertension is a condition that affects nearly 75 million people in the United States (Merai et al, 2017). To better understand this mostly idiopathic condition, the role of survival factors on arterial innervation must be understood. Nerve growth factor (NGF) and glial cell-line derived neurotrophic factor (GDNF) have been shown to support development and maintenance of the sympathetic nervous system. The aim of this study was to reveal how density of sympathetic innervation changes in mesenteric arteries over time and with six-months of exercise. Additionally, this study aimed to reveal the localization of GDNF and NGF alongside these changes in innervation. To accomplish this, density of sympathetic innervation was measured using ImageJ software in Sprague Dawley rats. Densities were measured in an exercised and sedentary group of one-year-old rats, an exercised and sedentary group of 18-month-old rats, and a group of four-week-old sedentary rats. The experiment revealed no significant changes in density of sympathetic innervation with exercise in both the one-year-old and 18-month-old groups. The density of sympathetic innervation was significantly less in the sedentary 18-month-old group than in the four-week-old group. There was no difference in density of innervation between the four-week-old group and the 18-month-old exercised group suggesting that exercise blocked the decrease in sympathetic innervation. There was also no difference in the density of innervation between the four-week-old group and either of the one-year-old groups. GDNF and NGF do not appear to be localized within sympathetic innervation. NGF appears to be localized around adipocytes but more research must be conducted to confirm this result and its implications.

Access Setting

Honors Thesis-Open Access