Dissertations, Theses, and Capstone Projects

Date of Degree


Document Type


Degree Name



Cognitive Neuroscience


Jeff Beeler

Subject Categories

Animal Studies | Behavioral Neurobiology


high fat diet, dendritic spines, striatum, addiction, obesity


Obesity rates have been dramatically rising in recent years and in 2017-2018 more than 42% of adults in the United States were obese. Obesity is associated with numerous health problems, including cardiovascular disease, stroke, insulin resistance, and type II diabetes. The prevalence of highly palatable and calorically dense foods high in fats and sugars is a significant factor in the increase in obesity rates. Many suggest that palatable food affects the brain in ways similar to drugs of abuse, reinforcing the consumption of highly palatable foods in the same way drugs reinforce drug use. While numerous weight loss programs and diets suggest that simply reducing caloric intake will result in weight loss, the weight loss is usually difficult to maintain long term and results in rebound of weight gain, reflective of a similar behavioral phenotype observed in drugs of abuse. The persistence of the condition suggests that persistent changes in neural circuits may be occurring that result in the long-term maintenance of increased body weight. The neural circuitry involved in drugs of abuse and obesity overlaps as well, with the dopamine pathway system being critically implicated in both. In this study, we focused on the dorsolateral striatum, an area in the dopamine system known to be involved in habit formation, and addictive and compulsive behaviors. We sought to investigate the effect of a high fat diet on alterations in dendritic spines, a synaptic modification that may be involved in shaping dorsolateral striatal activity and properties, contributing to the behavioral phenotype observed in obesity. To do this we used DiOlistics to label the two main cell types in the dorsolateral striatum, D1 and D2 medium spiny neurons, and analyze the differences in dendritic spines between high fat diet fed mice and control chow fed mice.