Ulrich-Lai Laboratory - Research Focus

Overview

Our research goal is to identify the neural and hormonal substrates that are responsible for the interactions among diet, obesity, and stress.  Obesity is a major health problem affecting 30% of adults in the United States.  Despite public health efforts to combat obesity, it continues to rapidly increase in incidence, along with obesity-related diseases and health costs.  Similarly, stress-related psychiatric disorders, including depression and anxiety, affect large segments of the population and place a substantial toll on patients, families, and communities.  Notably, there is a high co-morbidity between obesity/metabolic disorders and stress-related psychiatric disorders, supporting the idea that there are complex interactions among stress, obesity, and diet.  For instance, stress generally increases the intake of palatable ‘comfort’ foods (which can promote obesity), and the ingestion of these foods improves mood and decreases emotional and behavioral responses to stress.  However, the mechanisms underlying these interactions among are unknown, and this knowledge is needed to identify novel therapeutic targets for the prevention and treatment of obesity, as well as other stress-related disorders.

Research Projects

Stress relief by ‘comfort foods’:

This project seeks to understand how eating tasty foods curbs stress, and further asks if this stress relief becomes less effective in obesity.  More specifically, the project identifies the forebrain endocannabinoid mechanisms by which “comfort” food (sucrose) intake reduces hypothalamic-pituitary-adrenocortical (HPA) axis and metabolic responses to an acute stress challenge, and further determines how Western diet interferes with these stress-dampening endocannabinoid mechanisms.  This has important implications, as it suggests a vicious cycle whereby obese individuals continually increase their comfort food consumption in order to maintain effective stress relief, at the cost of worsening metabolic health.  Our work on this project is in collaboration with Dr. Matia Solomon (University of Cincinnati), Dr. Jeff Tasker (Tulane University), and Dr. Matt Hill (University of Calgary).

Stress resilience by natural rewards: neurocircuit mechanisms:

This project explores the idea that altered activity in brain stress-reward circuits drives the stress-buffering effects of pleasurable behaviors, and provides new information that will be critical for generating strategies to enhance stress resilience.  More specifically, the project identifies the neurocircuit mechanisms by which chronic engagement with a natural reward protects from the adverse consequences of chronic stress on anxiety- and sociability-related behaviors.  Collaborators on this project include Drs. James Herman, Seongho Song and Xia Wang from the University of Cincinnati.

Role of the gastrointestinal lymphatic system in hormonal signaling:

The overall purpose of this project is to determine the physiological relevance of (1) high lymph incretin concentrations, (2) high glucocorticoid levels in intestinal lymph, and (3) sex and the estrous cycle in intestinal lymph physiology. This is a collaborative project with Drs. Patrick Tso and Min Liu at the University of Cincinnati.