Research:
Brain Regulation of Food Intake and Energy Metabolism, Obesity.

Teaching:
Human Nutrition.

Interests:
The control of body weight is a complex process that appears to involve the interplay of many mechanisms, some as yet undefined. Recent research advances have highlighted the crucial role of brain circuitry in body weight regulation, but for every advance in this area new questions have risen.

My research interests focus on brain regulation of food intake and energy metabolism, how food intake is regulated and what signals are involved in hunger or satiety. I am also interested in research related to palatability or reward consummatory behavior. We are studying several neuroregulators such as opioid peptides and the melanocortins brain pathways regulating energy balance.

A corollary research interest is regulation of the uncoupling proteins, which influence energy expenditure and may provide feedback information to the brain. The uncoupling proteins uncouple ATP-formation during normal cellular respiration and energy consumed is expended as heat rather than stored. Alterations in the activity of some or all of the uncoupling proteins can dramatically influence energy expenditure. The activity of these uncoupling proteins are influenced by all known brain regulators of feeding, and thus the regulation of feeding and energy expenditure are closely linked in normal individuals. It is conceivable that uncoupling proteins could be targeted to enhance energy expenditure in obese individuals, or to decrease energy expenditure in anorexic individuals.

The identification of neural pathways, which interact to alter feeding, and energy expenditure will provide a "road map" to follow when considering therapeutic approaches for eating disorders and/or obesity.

Education:

Selected Publications/Presentations:
Shrestha, Y.B., Wickwire, K. and S.Q. Giraudo. Action of MT-II on ghrelin-induced feeding in the paraventricular nucleus of the hypothalamus. Neuroreport 15(7): 1365-1367. 2004

Grossman, H.C., Hadjimarkou, M.M., Silva, R.M. Giraudo, S.Q. and R.J. Bodnar. Interrelationships between m opioid and melanocortin receptors in mediating food intake in rats. Brain Research 991:240-244. 2003

Olszewski, P.K., Wickwire, K., Wirth, M.M., Levine, A.S. and S. Q. Giraudo. Agouti-related protein: Appetite or Reward? Annals of the New York Academy of Sciences 994: 187-191. 2003.

Wirth MM, Olszewski PK, Levine AS, Giraudo SQ. Effect of Agouti-related protein on development of conditioned taste aversion and oxytocin neuronal activation. Neuroreport. 13(10): 1355-8, Jul 2002

Olszewski PK, Wirth MM, Shaw TJ, Grace MK, Billington CJ, Giraudo SQ, Levine AS. Role of alpha-MSH in the regulation of consummatory behavior: immunohistochemical evidence. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. 281(2): R673-80, Aug 2001

Olszewski PK, Wirth MM, Grace MK, Levine AS, Giraudo SQ. Evidence of interactions between melanocortin and opioid systems in regulation of feeding. Neuroreport. 12(8): 1727-30, Jun 2001

Wirth MM, Giraudo SQ. Effect of Agouti-related protein delivered to the dorsomedial nucleus of the hypothalamus on intake of a preferred versus a non-preferred diet. Brain Research. 897(1-2): 169-74, Apr 2001

Wirth MM, Olszewski PK, Yu C, Levine AS, Giraudo SQ. Paraventricular hypothalamic alpha-melanocyte-stimulating hormone and MTII reduce feeding without causing aversive effects. Peptides. 22(1): 129-34, Jan 2001

Wirth MM, Giraudo SQ. Agouti-related protein in the hypothalamic paraventricular nucleus: effect on feeding. Peptides. 21(9): 1369-75, Sep 2000

Giraudo SQ, Grace MK, Billington CJ, Levine AS. Differential effects of neuropeptide Y and the mu-agonist DAMGO on 'palatability' vs. 'energy'. Brain Research. 834(1-2): 160-3, 1999