The effects of the delta-opioid receptor agonist PN6047 on sucrose preference in rats – UROP Symposium

The effects of the delta-opioid receptor agonist PN6047 on sucrose preference in rats

Omosiuwa Enakpene

Research Mentor(s): Emily Jutkiewicz
Program: Biomed
Authors: Omosiuwa Enakpene, Emily M Jutkiewicz, Ph.D.

Abstract

Delta-opioid receptor (DOR) agonists have been shown to have antidepressant-like and anxiolytic-like effects in animal models (Chung and Kieffer, 2013); however, DOR agonists can also produce convulsive adverse effects. The novel DOR agonist PN6047 is a G protein-biased agonist that produces antidepressant-like effects without seizure activity (Conibear et al., 2020). Therefore, we are evaluating whether or not PN6047 reverses anhedonic-like effects produced by withdrawal from repeated administration of mu-opioid receptor agonists. The sucrose preference test is used to gauge anhedonic-like behaviors, which is the diminished capacity for pleasure since rats readily consume sucrose. In this assay, rats are presented with two volumetric sipper tubes, one with tap water and one with a sucrose concentration (0.01-1%), for 24 hr, and then the location of the sipper tubes is altered for 24 hr. Volume consumed over 24 hr from each sipper tube is recorded. Sucrose preference is calculated as the volume (ml) of sucrose solution consumed as a percent of the total liquid consumed (water and sucrose) over 24 hr. We predict that withdrawal from repeated morphine administration decreases sucrose preference as compared with repeated saline treatment. We also predict that PN6047 will increase sucrose preference 24 hr after the last repeated saline or repeated morphine injection. These data will demonstrate that PN6047 has antidepressant-like effects and reverses opioid withdrawal-induced anhedonia in rats.

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