Sade Spencer, Ph.D.

Assistant Professor, Department of Pharmacology

Assistant Professor, Department of Pharmacology


Summary

Research

Research Summary/Interests

Chronic drug use results in a variety of maladaptive neuroadaptations that set the stage for drug relapse even after protracted abstinence periods. It is our hope that a better understanding of the trajectory of the neuroplasticity, physiology, neurochemistry and behavior over the course of the development of relapsing, remitting addiction will aid in the rational design of new, more effective treatments for drug addiction. In the Spencer lab we have a broad interest in studying mechanisms related to the development of addiction as well as relapse in the late stages of the disease. We also want to better understand risk factors and psychiatric comorbidities associated with drug addiction. We are currently pursuing studies in two general project areas (outlined below).

Project 1. Examination of dopamine and glutamate interactions during cue-induced cocaine seeking and taking. We aim to validate a specific role of mesolimbic dopamine in controlling the key biological adaptations in the nucleus accumbens that underlie cue-induced relapse to cocaine use using viral mediated delivery of designer receptors exclusively activated by designer drugs (DREADDs) or optogenetics to activate and silence ventral tegmental area dopamine transmission during behavior. Surprisingly, earlier research has largely failed to consider the impact of voluntary resumption of drug intake during relapse on plasticity, which our model allows us to do. It remains to be seen what impact repeated drug relapse events might have on circuit function or long-term treatment outcomes.

Project 2: Identifying neural circuits encode the rewarding versus the aversive properties of THC. THC is the most widely used illicit drug worldwide, but enduring health consequences of its use are largely unknown. The drug displays a narrow dose reward window, but produces enduring neuroadaptations following chronic self-administration that resemble other drugs of abuse. Moreover, preliminary data indicate that the rostromedial tegmental nucleus (RMTg) may mediate some of the aversive properties of this drug. Understanding how both reward and aversion is encoded with use of this drug will help guide development of therapeutics for treating cannabis use disorder as well as designing non-addictive cannabinergic therapies for other disorders. We use genetic and behavioral pharmacology approaches to probe the underlying mechanisms contributing to THC reward and aversion during drug seeking and reinstatement.