James R. Fadel

Assistant Professor

Postdoctoral: Vanderbilt Univ Medical Center
Ph.D.: Ohio State University, Columbus, OH.
B.S. Wheaton College, Wheaton, IL

Research Focus:

Our interests are diverse but may be broadly grouped into the following categories. We combine anatomical, neurochemical, behavioral and molecular approaches to these studies:
   1. The neural basis for age-related changes in cognitive and homeostatic function. We focus primarily on interactions between hypothalamic neuropeptides (particularly orexin/ hypocretin) and acetylcholine and dopamine systems. Orexins play a prominent role in activation of the basal forebrain cholinergic system in response to stimuli related to homeostasis and regulate attentional function (collaborations with Dr. Josh Burk, William and Mary). Old animals show marked loss of orexin innervation of cholinergic neurons, which may link age-related changes in homeostatic function with cognitive decline. We are also attempting to restore orexin function in aged animals through virus-mediated gene transfer (collaboration with Dr. Steve Wilson of PPN).

   2. Anatomical and neurochemical substrates of stress and anxiety. The amygdala is implicated in the etiology and expression of affective disorders. Our collaborations with Drs. Larry Reagan and Marlene Wilson (both of PPN) focus on cellular and neurochemical alterations in the amygdala that accompany these phenomena and how pharmacological treatments may prevent or ameliorate these changes.

   3. HIV effects on CNS function. Increased evidence supports the hypothesis that HIV/AIDs-associated cognitive deficits reflect deleterious effects of HIV-related proteins (e.g. Tat) on selected brain regions and transmitter systems. Through collaborations with Dr. Rose Booze (Psychology) and colleagues we are investigating the effects of these proteins on forebrain dopamine systems.

Recent Publications

• Frederick-Duus D, Guyton MF, Fadel J (2007) Food-elicited increases in cortical acetylcholine release require orexin transmission. Neuroscience 149:499-507.
• Pasumarthi RK, Reznikov LR, Fadel J (2006). Activation of orexin neurons by acute nicotine. Eur J Pharmacol 535:172-176.
• Burghardt P, Pasumarthi R, Wilson MA, Fadel J (2006) Chronic wheel running modifies contextual fear-elicited fos expression in the rat amygdala. Pharm Biochem Behav 84:306-312.
• Reznikov LR, Reagan LP, Fadel J (in press). Activation of phenotypically distinct neuronal subpopulations in the basolateral amygdala following acute and repeated stress. J Comp Neurol.