Department of Biological Sciences
The Khan laboratory is focused on the neural mechanisms underlying food intake control, body weight regulation and glucosensation.
Significance of the work: Diabetes and obesity have reached epidemic proportions in the U.S. and México, and complications arising from these illnesses are believed to involve, among other factors, a dysfunction of critical brain circuits. Despite intensive study, very little is known about how the brain controls food intake or responds to changes in blood sugar levels. For example, overeating and obesity occur, in part, by disruptions in the brain’s circuitry controlling food intake, yet the exact mechanisms by which overeating occurs at the level of brain circuits are virtually unknown. Additionally, diabetics are known to suffer from a condition known as hypoglycemia associated autonomic failure (HAAF), in which they fail to respond appropriately to sudden drops in blood sugar. Although this condition partly involves defective sensing or processing of signals by the brain, the exact mechanisms underlying this metabolic disorder are unknown.
Methods to be learned: The students in this project will be introduced to behavioral, biochemical, anatomical, physiological and computational approaches to studying brain circuits. Additionally, depending on the projects assigned, students can also be part of larger teams studying the in vivo effects of appetite stimulation or hypoglycemia on brain chemistry and the activation of functional circuits subserving glucosensing and food intake control. Techniques employed in the Khan laboratory include: vascular catheterization, stereotaxic surgery, ex vivo tissue slice physiology, central and peripheral injections of hormones and neurotransmitters, fluorescence and immunoperoxidase immunocytochemistry, brain microdissection, immunoblotting of brain tissue, high resolution microscopy and confocal imaging, image analysis (deconvolution and three-dimensional rendering), and neuroinformatics database querying / inference construction.