Drug abuse; Circadian Rhythm/Chronobiology; Gene Expression; Molecular and Cellular Biology; Neuropharmacology
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 projections from the cortex to the striatum influence drug seeking behaviors, and 2) how neurotransmitter receptors, particularly dopamine and cannbinoid receptors in these regions influence drug seeking. Our technical approaches include a number of basic behavioral models including measurements of locomotor activity, catalepsy, conditioned place preference and drug self-administration. In order to probe the circuitry of these brain regions, 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 expression using RNA interference. Gene delivery is accomplished using recombinant adeno-associated virus (rAAV) and several projects in the laboratory focus on improving this approach 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 for addiction.
Drug abuse; Behavioral pharmacology; Signal Transduction; Neuropharmacology; Circadian Rhythm/Chronobiology
My lab‘s research seeks to understand the mechanism of action of the hormone melatonin at the MT1 and MT2 G-protein coupled receptors. We study these receptors in the brain and through the body with the goal of identifying ligands that exhibit useful binding affinity and therapeutic potential. Our team of undergraduate and graduate students, postdoctoral fellows, technicians and senior scientists work with each other and with expert co-investigators in medicinal chemistry to discover and develop novel molecules that can mimic or counteract the actions of melatonin. These molecules may help treat a variety of diseases and conditions including insomnia, circadian sleep disorders, depression, seasonal affective disorders, and cardiovascular disease. Our laboratory pursues these investigations from several angles. We assess the localization of the melatonin receptors, examine their cellular and molecular signaling mechanisms,and investigate receptor fate following prolonged exposure to melatonin. We study the distinct roles of selective MT1 and MT2 melatonin receptor ligands in modulating circadian rhythms, methamphetamine‘s ability to induce both sensitization to prolonged exposure, and stimulation of the reward system. We also study cell proliferation, survival, and neurogenesis in the brain, and the changes in gene expression underlying all these processes. Our research ultimately aims to discover novel drugs with differential actions at the MT1 and MT2 receptors. We use molecular-based drug design, computer modeling and medicinal chemistry to design and synthesize small molecules that target these receptors as agonists, inverse agonists and/or antagonists. We then pharmacologically and functionally characterize these molecules using cell-based assays and bioassays and test them in circadian and behavioral animal models.