Neural circuits and substrates underlying opioid and cocaine abuse. 

The Dobbs lab takes a systems-level approach to identify the neural substrates, circuits and behavioral motivations driving substance use disorders. Our current research focuses on how cocaine and opioids synergize in specific brain circuits to facilitate their rewarding effects.  To this end, we use transgenic mouse models to probe how specific opioid peptides and receptors in certain cell-types and brain regions contribute to cocaine seeking and taking. We use a variety of behavioral approaches to measure drug reward in the mouse, including self-administration approaches and conditioned place preference.  We also use brain slice electrophysiology to probe the plasticity of neural circuits in the brain's reward pathway after a history of drug exposure.

We are also interested in how synthetic opioids, like fentanyl, synergize with cocaine to facilitate their co-use. Reports from human drug users and preclinical studies suggest this may occur through multiple effectors and impact various aspects of reinforcement. For instance, cocaine may increase the rewarding properties of opioid drugs, or even curb the negative affective state induced by opioid withdrawal.  These different motivational causes for cocaine-opioid co-use may be mediated by distinct neural substrates and circuits.  To answer these questions, we use a variety of behavioral approaches to test the rewarding and aversive aspects of drugs of abuse, and employ other techniques like brain slice electrophysiology and in vivo optogenetics to assess how activity of specific cell types and circuits relates to these behaviors.

For more information on our research, see our .