Behavioral Neuroscience Lab

Our overall research program is aimed at identifying the roles of various neural signaling pathways in the controls of food intake and body weight. The current research takes a number of approaches. The first involves the identification of the neural representation of meal-related satiety signals. Multiple feedback signaling pathways are activated by food ingestion and the gastrointestinal presence of digestion products. We are examining how signals from multiple sites and stimulus modalities are integrated within specific brain nuclei and, in an effort to model eating disorders, how alterations in feeding patterns can influence these neural representations.

The second approach involves the identification of interactions between peripheral, within-meal, satiety signals and hypothalamic peptide systems involved in overall energy balance. We are currently examining how the activity of hypothalamic leptin, NPY, CCK, CFR, CART and melanocortin systems interact with ascending satiety pathways to alter meal size. We are also investigating how alteration in cellular energy availability and production are transduced into changes in food intake and body weight. These experiments focus on the de novo fatty acid synthesis pathway in critical hypothalamic sites and take advantage of a novel group of chemicals that inhibit the production of fatty acids and/or stimulate fatty acid oxidation. We are examining how exercise not only increases energy expenditure but also reduces food intake. These experiments focus on the regulation of peptide gene expression in hypothalamic systems involved in energy balance.

Finally, we are examining how gestational factors can bias metabolic programming to contribute to altered feeding and obesity. Experiments are conducted at multiple levels and employ behavioral, physiological and molecular in vivo and in vitro paradigms.

Lab Members

FACULTY
	Timothy H. Moran, Ph.D. Paul R. McHugh Professor of Motivated Behaviors Vice Chair for Research tmoran@jhmi.edu 410-955-2344 Faculty Profile

	Ellen E. Ladenhiem, Ph.D., Associate Professor laden@jhmi.edu 410-614-1750 My research interests involve delineating the role of bombesin-like peptides in the control of food intake. Bombesin-like peptides are found in the mammalian gastrointestinal tract and central nervous system and have been shown to suppress food intake when administered to a variety of mammalian species, including humans. The overall objective of this research program is to determine the neural pathways and mechanisms utilized by mammalian BN-like peptides to inhibit feeding and examine how these peptides interact with other peptides that participate in energy balance and body weight regulation. Faculty Profile

	Sheng Bi, M.D., Associate Professor sbi@jhmi.edu 410-502-4789 The goal of my research is to understand how hypothalamic peptide signaling affects food intake and energy balance by using various techniques such as in situ hybridization, immunohistochemistry, central peptide administration and recombinant adeno-associated virus system for delivering genes or RNA interference with short interfering RNA (siRNA). In addition, we do in vitro studies to understand the regulation of energy metabolism at molecular biological levels using techniques such as cell culture, gene transfection, Western blotting, Northern blotting and real time RT-PCR. Faculty Profile

	Kellie L. K. Tamashiro, Ph.D., Associate Professor ktamashiro@jhmi.edu 410-955-2996 Overweight and obesity is a growing public health problem worldwide, particularly among children. My current studies examine how environmental manipulations during development, specifically the intrauterine and early postnatal environments, influence the metabolic phenotype of the offspring. We are using a rat model to study the short- and long-term behavioral, neuroendocrine, and metabolic consequences of prenatal stress and changes in maternal nutrition. Faculty Profile

POSTDOCTORAL FELLOWS
	Gretha Boersma, Ph.D. gjboersma@hotmail.com 410-955-2996 My overall research goal is to investigate the neurobiological mechanisms underlying individual differences in both metabolic and stress-related disorders. My previous studies have shown that the stress coping style predicts the vulnerability for obesity and associated insulin resistance. My current work focuses on the developmental aspects of individual difference in metabolic phenotype using behavioral, physiological and molecular techniques to investigate the complicated interactions between genes and environment. Determining the interactions between the early pre-and post-natal environment and the stress coping style will help unravel the mechanism(s) underlying increased vulnerability for metabolic disturbances.

	Megan Dailey, Ph.D. mdailey5@jhmi.edu 410-955-2996 Have you ever just finished dinner at your favorite restaurant and feel very full, but decide to eat a dessert anyway? When the clock strikes noon, do you pull out your lunch and eat even if you are not hungry? Do you ever have a craving for a specific food – crunchy, salty, soft, sweet – that no other food will suffice? I am interested in the physiological factors that determine the decision when to eat, how much to eat and what to eat. The need for calories is a powerful drive to initiate food intake, but is clearly not the only reason why we eat. The importance of food intake to our survival ensures that there are multiple systems that drive the decision to eat. My research utilizes rodent models to understand the underlying mechanisms driving feeding behavior with a focus on two main areas of research: the circadian rhythm of feeding behavior and the influence of environmental cues in the potentiation of feeding.

	Nu-Chu Liang, Ph.D. nlaing2@jhmi.edu 410-955-2996 I study the underlying mechanisms of the effects of exercise on food intake and diet preference with a rat wheel running model. I am also interested in studying the neural mechanisms of anorexia, and the models used for this include activity based anorexia, conditioned taste aversion, and chronic variable stress.

	Yada Treesukosol, Ph.D. yadatree@jhmi.edu 410-955-2996 Taste interacts with post-oral physiology to control feeding and drinking behavior. Thus, understanding the gustatory signal processing can provide a useful tool for understanding more complex behaviors related to nutrition and obesity. My overarching research interests involve an integrated approach of taste psychophysics and techniques to discern the neurobiological effects that influence energy balance.

STUDENT
	Jenny Albertz jalbertz66@gmail.com 410-955-2996 Anorexia nervosa has the highest mortality rate of any psychiatric disorder, can be found within all cultures, and has no widely effective treatment. However, the neurological mechanism(s) are poorly understood. To study this illness in the lab, my research utilizes a rodent model of anorexia, termed activity-based anorexia, which closely mimics many of the human physiological symptoms of anorexia. Using this model, I am investigating hormones and neurotransmitters that play a role in food intake and energy balance (such as leptin, AgRP, and α-MSH) which could be contributing to, or sustaining, anorexia.