The Department of Neuroscience Welcomes Stephanie Borgland.
Dr. Stephanie Borgland is a Professor and a Tier 1 Canada Research Chair in the Departments of Physiology & Pharmacology as well as Psychiatry at the University of Calgary.
The misuse of opioids and other prescription pain relievers has risen rapidly, becoming a major global health issue. Addiction is linked to neural circuit dysfunction, characterized by changes in synaptic transmission in the ventral tegmental area (VTA), a region involved in the incentive value of drug-related stimuli. The lateral hypothalamic (LH) neuropeptide, orexin (ox; also known as hypocretin), is necessary for the formation of morphine induced plasticity of VTA dopamine neurons. Orexins and dynorphin (dyn) are co-expressed LH neuropeptides that project to VTA. These peptides have opposing effects on the firing activity of VTA dopamine (DA) neurons via orexin 1 (Ox1) or kappa opioid (KOR) receptors, respectively. Therefore, it is unclear how the co-released peptides contribute to the activity of dopamine neurons in physiological and pathological states. This study aimed to determine how chronic morphine alters the contributions of LHox/dyn to the firing of VTA DA neurons. We found that repeated opioid treatment shifts the LHox/dyn regulation of VTA dopamine neurons that project to the BLA from inhibitory to primarily excitatory. This may influence the responsiveness of the mouse to opioid-related cues.