Current Research Interests and Projects:
The Laboratory of Neuropharmacology is located at the VA Medical Center in 7000sq ft of space dedicated to Neuroscience research. Research focuses on the role of the brain in regulating energy homeostasis in the body. All work begins in animal models in which various physiologic and neuroendocrine responses are assessed in vivo. Further in vitro studies in these animals involve molecular, physiologic and biochemical procedures. There are two major, interrelated foci of study. The brain senses and integrates metabolic signals (e.g. glucose, fatty acids, leptin, insulin) relating to bodily energy stores using a specialized class of metabolic sensor-integrator neurons. These neurons contain ion channels and receptors for such metabolic signals. They are part of larger neural networks involved in arousal, reward, motivation, stress, autonomic, hypothalamo-pituitary activity and ingestive behavior. We study the effect of diseases such as obesity and diabetes on the function, development and plasticity of these metabolic sensing neurons. Animal models of these diseases are used to perturb the maternal, perinatal and adult environment to examine the effects on these neurons and the physiologic processes they regulate. Specific emphasis centers on brain monoamine and neuropeptide systems involved in energy homeostasis and select neurons that use glucose as a signaling molecule (glucosensing neurons). Techniques include: genetic models of obesity and diabetes, in vivo monitoring of plasma constituents by indwelling catheters in awake animals, cerebral microdialysis, HPLC for monoamines, receptor binding autoradiography, in situ hybridization, immunocytochemistry, single cell Ca2+ imaging combined with single cell PCR, RNAi, radioimmunoassay and a variety of molecular biological techniques.

Representative Publications:
Levin,B.E. and Routh,V.H. "Role of the brain in energy balance and obesity". Am. J. Physiol. 271: R491-R500, 1996.

Levin,B.E., Dunn-Meynell,A.A., Balkan,B. and Keesey,R.E., "Selective breeding for diet-induced obesity and resistance in Sprague-Dawley rats.", Am. J. Physiol. 273: R725-R730, 1997.

Levin, B.E. and Keesey, R.E., "Defense of differing body weight set-points in diet-induced obese and resistant rats.", Am. J. Physiol. 274: R415-R419, 1998.

Levin, Barry E., Arcuate NPY neurons and energy homeostasis in diet-induced obese and resistant rats, Am. J. Physiol. , 276: R382-R387, 1999.

Levin, B.E., Dunn-Meynell, A.A. and Routh, V.H., "Brain glucosensing and body energy homeostasis: role in obesity and diabetes", Am. J. Physiol. 276: R1223-R1231, 1999.

Tkacs , N.C. , Dunn-Meynell, A.A., and Levin, B.E., "Apoptosis and reduced arcuate nucleus NPY and POMC mRNA in non-coma hypoglycemia", Diabetes. 49: 820-826, 2000.

Levin, B.E., Richard, D., Michel, C and Servatius, R., "Differential stress responsivity in diet-induced obese and resistant rats", Am. J. Physiol. 279: R1357-R1364, 2000.

Levin, B.E., "The obesity epidemic: metabolic imprinting on genetically susceptible neural circuits", Obes. Res. 8: 342-347, 2000.

Levin, B.E., "Metabolic sensors: viewing glucosensing neurons from a broader perspective", Physiol.Behav. 76: 397-401, 2002.

Dunn-Meynell, A.A., Routh, V.H., Kang, L., Gaspers, L. and Levin, B.E., "Glucokinase is the likely mediator of glucosensing in both glucose excited and glucose inhibited central neurons", Diabetes 51: 2056-2065, 2002.

Levin, B.E. and Dunn-Meynell, A.A., "Reduced Central Leptin Sensitivity in Rats with Diet-induced Obesity", Am J. Physiology. Am. J. Physiol. 283: R941-R948, 2002.

Levin, B.E. and Dunn-Meynell, A.A., "Maternal Obesity Alters Adiposity and Monoamine Function in Genetically Predisposed Offspring", Am. J. Physiol. 283: R1087-R1093, 2002..

Levin, B.E., "Metabolic imprinting and the obesity epidemic", Opin. Endocrinol. Diabetes, 9: 375-380, 2002.
Levin, B.E. and Dunn-Meynell, A.A., "CNS sensing and regulation of peripheral glucose levels", Int. Rev. Neurobiol. 51: 219-258, 2002.

Levin, B.E., Dunn-Meynell, A.A., Ricci, M.R. and Cummings, D.E., "Abnormalities of leptin and ghrelin regulation in obesity-prone juvenile rats", Am.J.Physiol. 285: E949-E957, 2003.

Michel, C., Levin, B.E. and Dunn-Meynell, A.A., "Stress facilitates body weight gain in genetically predisposed rats on medium fat diet", Am.J.Physiol. 285: R791-R799, 2003.

Levin, B.E., Dunn-Meynell, A.A. and Banks, W.A., "Defective central leptin signaling antedates the development of diet-induced obesity in rats", Am.J.Physiol. 286: R143-R150, 2004.

Kang, L., Routh, V.H., Kuzhikandathil, E.V., Gaspers, L.D. and Levin, B.E., "Physiological and molecular characteristics of rat hypothalamic ventromedial nucleus glucosensing neurons", Diabetes 53: 549-559, 2004.

Levin, B.E. and Dunn-Meynell, A.A., "Chronic exercise lowers the defended body weight gain and adiposity in diet-induced obese rats", Am. J. Physiol. 286: R771-R778, 2004.