Ongoing Projects

Investigating the Behavioural Synergism and Sex Differences Between Mu Opioid Receptor Agonism and Positive Allosteric Modulation in Rats

Opioid analgesics have become the most commonly prescribed treatment for moderate to severe acute pain, and while efficacious, they possess an exceptional abuse potential resulting from their sedative, potent analgesic, and euphoric properties. Thus, the need for drugs that can provide adequate analgesia, but lack the adverse effects common to exogenous opioid administration is great and is an emerging area of research. A recent study has determined that the Mu opioid receptor (MOR) positive allosteric modulator (mu-PAM) BMS-986122 (BMS) can enhance endogenous opioid peptide activity while producing decreased levels of morphine-like adverse effects due to its lack of binding at the MOR orthosteric site. Thus, the purpose of this study is to begin to elucidate if and how interoceptive stimuli differ upon administration of morphine and the mu-PAM, BMS.

The effects of punishment contingency on oral morphine consumption in male and female Sprague-Dawley rats

Altering opioid circuitry through uncontrollable stress could expose an overlap in analgesic and reinforcement systems through the manifestation of the oprm1 gene that is highly expressed in the periaqueductal gray (PAG) area of the brain. The simultaneous activation of both analgesic and reinforcement systems impacts the mesocorticolimbic circuit that mediates a variety of behaviours ranging from reinforcement learning to a conditioned preparatory response that is evident in controlled stress. Fundamental research into how stressors interact with opiate reinforcement to promote neuroplasticity is important to further our understanding of the basal role of these systems and how they help to integrate environmental exposures. The goal of this project is to expand on current understanding by manipulating the psychological variable of controllability of foot shocks in combination with Mu Opioid Receptor (MOR) activation by virtue of oral morphine self-administration in male and female rats to study the behavioural and brain circuit changes arising from these manipulations.

An Investigation of the Role of Dopamine in Morphine as an Occasion Setter

The current study seeks to identify the role of dopamine in Pavlovian occasion setting, using morphine as an occasion setter; additionally, the study is intended to establish a more inclusive dose-response curve in male and female rats during morphine dose generalization testing.

The Non-Discrimination Between Nicotine and Cigarette Smoke Extract in Rats

The goal of this project is investigating whether animals can discriminate between nicotine alone and nicotine in cigarette smoke extract based on interoceptive cues. Next steps include proteomic analysis to determine if there is differential expression between these two substances in regions of the brain involved in addiction and reward. Avery and Brandon contributed to this work during their time in the lab; Davin, Jessica and McKenna are currently helping on this project.