
Associate Professor
Department of Pharmacology and Toxicology
Jacobs School of Medicine & Biomedical Sciences
Addictions; Addictions; Behavioral Neuroscience; Behavioral pharmacology; Brain Research; Drug Abuse; Drug abuse; Gene Expression; Gene Therapy; Molecular and Cellular Biology; Neurobiology; Neuropharmacology; Neuropsychiatric Disorders; Neuroscience; Pain
My laboratory seeks to understand the neurobiology of motivation and how these systems can be "highjacked" by abused substances. Substance abuse and addiction are wide-spread problems that have an enormous economic and emotional toll. Reports indicate that it costs the US upwards to $600 billion a year to deal with the health and criminal consequences and loss of productivity from substance abuse. Despite this, there are few effective treatments to combat this illness.
The brain has natural systems responsible for motivating an organism to participate in behaviors that are necessary for survival, such as eating, exercise and reproduction. These same brain regions are highly sensitive to drugs of abuse, including cocaine, heroin and marijuana. My laboratory seeks to understand how these brain regions are affected by exposure to abused drugs, and in particular how the motivation to take drugs is altered by various molecular mediators in the neurons on these regions. The two basic questions we are interested in are 1) how the ventral segmental area, nucleus accumbens and prefrontal cortex interact to influence reward-seeking behaviors, and 2) how do dopamine and GABA neurotransmission in these regions influence drug seeking. We are currently focused on understanding how VTA GABA projections coordinate activity in and between the NAc and PFC in adaptive decision-making when weighing the relative cost and benefit of pursuing rewards. Such behavioral mechanisms are necessary to ensure animals have the best chance of survival in an environment where resources are constantly shifting.
A secondary focus of the laboratory is how these mesocorticolimbic circuits mediate the effects of mood on pain perception. Pain is a complex experience that can be heavily influenced by executive function and mood. Using behavioral models of pain affect such as the place escape avoidance paradigm (PEAP), we have demonstrated that the endocannabinoid system modulates the affective components of pain moreso than the sensory, and indicating that medical marijuana may be alleviating pain via the affective pain circuits.
Our technical approaches includes preclinical behavioral models such as locomotor activity, catalepsy, conditioned place preference, PEAP and food and drug self-administration. In order to probe the mesocorticolimbic circuitry, we use a number of advanced molecular techniques to activate and inactivate neuronal populations including optogenetics and artificial receptors. We probe the molecular pathways within the neurons by over expressing genes or knocking down their expression using RNA interference and CRISPR approaches. Gene delivery is accomplished using recombinant adeno-associated virus (rAAV) and several projects in the laboratory focus on improving viral gene delivery and exploring potential gene therapy applications for these vectors. The ultimate goal is to understand the basic neurobiology and molecular biology of addiction in order to develop more effective treatments.