The Parabrachial Nucleus and Cellular Mechanisms for Eating for Pleasure
Friday, January 17, 2014
4:00 PM-5:30 PM
Kenny J. Simansky, PhD, vice dean for research, professor of pharmacology, Department of Pharmacology and Physiology, Drexel University College of Medicine, will discuss how obesity itself diminishes an individual’s quality of life and is associated with serious physiological and behavioral pathologies. In the US, 1/3 of the adults are obese and another 3rd are overweight. Rates are increasing for children and the global profile is similar across developed nations. This public health threat might be surprising given the multiple, redundant mechanisms that regulate energy intake, storage and utilization. It is well-established, however, that humans and non-human animals will eat foods that are highly preferred in amounts greater than needed to satisfy energy regulation. Overeating for pleasure (i.e., “non-homeostatic or hedonic eating”) is a prominent cause of obesity and relies upon neural circuits in the brain that serve reward-related behavior. Although these circuits are generally identified with the forebrain, we established such a role for the parabrachial nucleus (PBN) in the brainstem. In rats, the PBN receives input from taste, the viscera and other sensory modalities and projects to loci in the forebrain involved in autonomic regulation, cognitive function and reward. Local infusion of nanomole amounts of agonists for mu-opioid (MOPR) and cannabinoid (CBR) receptors activates G-protein coupling and increases eating. MOPR antagonists block acute stimulation of G-protein coupling within the PBN and the increase in food intake. We demonstrated that the (+)-isomer of the classical opioid antagonist naloxone could increase, rather than decrease opioid activity. This has therapeutic implications. In concert, the data support a function for this brainstem locus as an early site in the physiological pathways for reward and specific roles for parabrachial opioids and cannabinoids in the underlying cellular mechanisms. For more info, please visit: www.biomed.drexel.edu.
Papadakis Integrated Sciences Building (PISB), Room 120, located at the corner of 33rd and Chestnut Streets.
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