James R. Fadel

Associate Professor

Email: jim.fadel@uscmed.sc.edu

Phone:  803-216-3505 
FAX: 803-216-3538

Website: jfadel.htm

Postdoctoral:  Vanderbilt University, Nashville, TN

PhD:  Ohio State University, Columbus, OH.

BS: Wheaton College, Wheaton, IL.

Research Interests:

Our interests are diverse but may be broadly grouped into the following categories.  We combine anatomical, neurochemical, behavioral and molecular approaches to these studies, which are funded by a combination of federal (NIH), charitable advocacy organization, and industry sources:

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.

Recent Publications:

• Frederick-Duus, D., Guyton, M.F. and Fadel, J. (2007)  Food-elicited increases in cortical acetylcholine release require orexin transmission.  Neuroscience 149:499-507.
• Reznikov, L.R., Reagan, L.P. and Fadel, J. (2008)  Activation of phenotypically distinct neuronal subpopulations in the rat basolateral amygdala following acute and repeated stress.  Journal of Comparative Neurology 508:458-472.
• Fadel, J. and Burk, J.A. (2010) Orexin/hypocretin modulation of the basal forebrain cholinergic system: role in attention. Brain Research 1314:112-123.
• Pasumarthi, R.K. and Fadel, J.  (2010) Stimulation of lateral hypothalamic glutamate and acetylcholine efflux by nicotine: implications for mechanisms of nicotine-induced activation of orexin neurons. Journal of Neurochemistry, In press.
• Fadel, J. (2010) Regulation of cortical acetylcholine release: insights from in vivo microdialysis studies. Behavioural Brain Research, In press.

Left: Orexin fibers (black) innervate basal forebrain cholinergic neurons (brown). Right: GFP-expressing neuron in the basal forebrain (left panel) is also positive for orexin A (right panel) following prepro-orexin lentivirus administration.