We have two main lines of research at the moment:
1. Food reward and metabolic hormones. We are interested in the ability of metabolic hormones, secreted when we eat, to act on brain areas to modulate food reward. Specifically, we are investigating the actions of insulin and leptin on the hypothalamus and reward areas such as the nucleus accumbens and ventral tegmental area. Our studies include the neuroanatomical mapping of receptor expression, post-receptor biochemical and cellular events, and behavioral studies that include self-administration and the conditioning of a preference for a place where rats receive food treats. We are interested in how rats' performance in these paradigms may be altered by their ambient diet and its fat composition. These studies should shed light on the non-adaptive eating patterns of people in the U.S. and other Westernized societies who have virtually unlimited access to tasty, high caloric density food.
2. Brain mechanisms of impaired neuroendocrine responses to hypoglycemia. We are characterizing the pattern of impaired activation of brain circuitry which organizes and initiates neural/hormonal responses to stressors. Specifically we are studying hypoglycemia stress, a problem in diabetic patients who self-administer insulin or oral agents. With frequent bouts of low blood sugar occurring closely in time, there is a response failure of the critical hormones which turn on very rapid biochemical responses for correction of blood glucose levels. Our lab has identified several vulnerable brain areas and we are beginning to characterize the neurochemical basis(es) for this impaired response.
Recent articles of interest:
AM Naleid, JW Grimm, DA Kessler, AJ Sipols, S Aliakbari, JL Bennett, J Wells, and DP Figlewicz. Deconstructing the vanilla milkshake: the dominant effect of sucrose on self-administration of nutrient-flavor mixes. Appetite 50: 128-138, 2008.
S Al-Noori, NM Sanders, GJ Taborsky, Jr., CW Wilkinson, A Zavosh, C West, CM Sanders, and DP Figlewicz. Recurrent hypoglycemia alters hypothalamic expression of the regulatory proteins FosB and synaptophysin. American Journal of Physiology 295: R1446-R1454, 2008.
DP Figlewicz and SB Benoit. Insulin, leptin, and food reward: Update 2008. American Journal of Physiology 296: R9-R19, 2009.