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College of Osteopathic Medicine of the Pacific

Neurobiology

Neurobiology

Xiaoning Bi Xiaoning Bi, MD, PhD
Professor of Physiology
COMP-Pomona
xbi@westernu.edu
Office#: (909) 469-5487 – Lab#: (909) 469-5471
Research Interests: Research in my laboratory seeks to understand how neurons develop, mature, and function properly, and how they die when challenged by natural aging process, intrinsic genetic defects, or various insults. We hope that, by understanding the basic molecular and cellular mechanisms that govern these processes, we can develop better preventive and therapeutic strategies for central nervous system disorders in children as well as in elders. Current Research Projects: 1. Signaling pathways in learning and memory and other brain functions. Signal transmission at junctions between neurons, the synapses, is regulated by multiple signaling pathways. One of my lab projects for the last few years has focused on the mTOR (mechanistic/mammalian target of rapamycin) signaling pathway. The mTOR network consists of two complexes mTORC1 and mTORC2 and integrates signals from nutrients, energy levels, growth factors, and stress status. We have recently found that mTORC1 activity is increased while mTORC2 activity is decreased in a mouse model of Angelman syndrome (AS), a disease caused by maternal UBE3A deficiency. Furthermore, the imbalanced mTORC1 and mTORC2 activity is causally related to learning and memory impairment and motor dysfunction in AS mice. These results suggest that mTOR signaling is regulated by UBE3A. Since abnormal mTOR signaling has been reported in other neurological disorders, including Alzheimer’s disease and autism spectrum disorders, our findings may have broad implications. 2. Regulation of potassium channels by UBE3A Small conductance calcium-activated potassium channels (SK1-3) are widely distributed throughout the brain and other organs. SK2 channels play important roles in learning and memory and in abnormal brain functions, such as seizures. We have demonstrated that synaptic SK2 levels are regulated by UBE3A and the lack of this regulation resulting from UBE3A deletion contributes to learning impairment in Angelman syndrome mice. Since SK2 channels are widely expressed in mammalian brain, these findings have significant implications for a vast array of neurologic/neuropsychiatric disorders.
Portrait of Nissar A. Darmani Nissar A. Darmani, PhD
Associate Dean for Basic Sciences and Research Chair, Basic Medical Sciences
COMP-Pomona
ndarmani@westernu.edu
Office#: (909) 469-5654 – Lab#: (909) 469-5218
Research Interests:

  • Developmental effects of drugs of abuse on the newborn.
  • Serotonergic mechanisms of cocaine’s actions.
  • Mode of action of antidepressant drugs.
  • Adaptive mechanisms of serotonergic 5-HT2 receptor functions.
  • The role of delta-9 -THC and synthetic cannabinoids on chemotherapy- and radiotherapy-induced vomiting. His laboratory had the first opportunity to demonstrate the mechanisms of antiemetic actions of marijuana.
  • Role of 5-HT3-, Dopamine D2/3-, Lekotriene CysLT1- and NK1- receptors in emesis and application of their antagonists as antiemetics.
  • Another of his research interests involves the role of osteopathic manipulative medicine on the blood levels of endogenous cannabinoid-like compounds and other pain markers in patients with back pain. He had been successful in obtaining several million dollars of research grants from numerous funding agencies including the Pharmaceutical industry, the National Institute of Drug Abuse, the National Institute of Cancer, the Department of Defense and the Environmental Protection Agency.
Edward Wagner Edward Wagner, PhD
Professor of Physiology
COMP-Pomona
ewagner@westernu.edu
Office/Lab#: (909) 469-5239
Research Interests: My research interests focus on how cannabinoids regulate the hypothalamic feeding circuitry to affect changes in feeding behavior and energy homeostasis in male and female subjects, and how gonadal steroids modulate this interaction. I use state-of-the-art instrumentation to assess cannabinoid-induced changes in daily and hourly food intake, as well as meal size, frequency and duration, core body temperature and weight gain/loss, and how these changes correlate with alterations in neurotransmitter release and cell excitability at anorexigenic proopiomelanocortin (POMC) synapses within the hypothalamic arcuate nucleus. I recently have discovered that males are much more sensitive to the appetite-modulating properties of CB1 receptor agonists and antagonists than females, which correlates with marked sex differences in the pre- and post synaptic actions of cannabinoids at POMC synapses. These findings indicate that gender should be taken into account when considering the use of cannabinoids in the treatment of HIV/AIDS- or cancer-related cachexia, or obesity.