Robert L. Patrick Associate Professor of Medical Science

I study psychoactive drugs such as amphetamine and cocaine for two main purposes: (1) to understand the alterations in the regulation of brain chemicals that can occur as a result of exposure to psychoactive drugs, and (2) to make use of possible animal models of psychiatric disorders. People who use stimulant drugs such as amphetamine and cocaine on a chronic basis can develop a psychosis that is similar to paranoid schizophrenia. This is of interest in light of our findings that chronic administration of amphetamine to rats can increase the utilization of dopamine, a brain neurotransmitter. To show this, we use microdialysis, a technique for analyzing neurotransmitter release in the brain. The alterations produced in transmitter utilization in the rat brain during chronic stimulant drug administration may be very similar to the changes occurring in the human brain exposed to stimulant drugs. These studies may provide insight into the biochemical changes occurring in the human brain that can contribute to the development of psychiatric disorders.

Brown Affiliations

scholarly work

Patrick, R.L. (2000) Synaptic clefts are made to be crossed: Neurotransmitter signaling in the central nervous system. Toxicologic Pathology, 28: 31-36.

Sanudo-Pena, M.C., Patrick, S.L., Khen, S., Patrick, R.L., Tsou, K. and Walker, J.M. (1998) Cannabinoid effects in basal ganglia in a rat model of Parkinson's disease. Neuroscience Letters, 248: 171-174.

Patrick, S.L., Thompson, T.L., Walker, J.M. and Patrick, R.L. (1991) Concomitant sensitization of amphetamine-induced behavioral stimulation and in vivo dopamine release from rat caudate nucleus. Brain Research, 528: 343-346.

Thompson, T.L., Colby, K.A. and Patrick, R.L. (1990) Activation of striatal tyrosine hydroxylase by in vivo electrical stimulation: Comparison with cyclic AMP-mediated activation. Neurochemical Research, 15: 1159-1166.

research overview

Our research is aimed at elucidating how alterations in neurotransmitter activity in the central nervous system influence behavior. We are especially interested in determining how chronic administration of a psychoactive drug, such as amphetamine, alters brain functioning from both a behavioral and transmitter point of view.

research statement

Our research is aimed at elucidating how alterations in neurotransmitter activity in the central nervous system influence behavior. We are especially interested in determining how chronic administration of a psychoactive drug, such as amphetamine, alters brain functioning from both a behavioral and transmitter point of view. In order to analyze the relationship between transmitter release and animal behavior, we use a microdialysis procedure that enables us to carry out concurrent measurements of transmitter release from the rat brain while monitoring animal behavior. In vivo release studies are complemented by in vitro studies of nerve ending (synaptosome) preparations isolated from discrete brain areas in order to study drug effects on transmitter synthesis, release, and uptake. Our hope is that these combined in vivo and in vitro studies will help elucidate the mechanisms via which chronic psychoactive drug administration alters the sensitivity of the brain to subsequent psychoactive drug exposure.

funded research

Research Grants Funded: Amounts Represent Direct Costs

A. Completed Grants

1978-1981 National Institute of Mental Health (NIMH). Catecholamine Regulation and Psychoactive Drugs: $120,000. PI: Robert L. Patrick.

1980 Brown University Biomedical Research Support Grant (BRSG): $5,370. PI: Robert L. Patrick.

1981-1982 American Heart Association, Rhode Island Affiliate. Stress, Catecholamines and Hypertension: $8,000. PI: Robert L. Patrick.

1982 Rhode Island Foundation. Stress, Catecholamines and Hypertension: $4,000. PI: Robert L. Patrick.

1982 Brown University BRSG: $35,654. PI: Robert L. Patrick.

1982-1984 NIMH. Catecholamine Regulation and Psychoactive Drugs: $100,000. PI: Robert L. Patrick.

1983 Rhode Island Foundation. Propranolol, Catecholamines and Hypertension: $3,500. PI: Robert L. Patrick.

1983-1984 American Heart Association, Rhode Island Affiliate. Propranolol, Catecholamines and Hypertension: $12,190. PI: Robert L. Patrick.

1984-1986 Scottish Rite Schizophrenia Research Program. Isolation and Characterization of Dopaminergic Nerve Endings: $29,583. PI: Robert L. Patrick.

1984-1987 American Heart Association. Propranolol Mechanisms in the Central Nervous System: $82,000. PI: Robert L. Patrick.

1986-1992 NIMH. Catecholamine Regulation and Psychoactive Drugs: $228,665. PI: Robert L. Patrick.

1988 Burroughs Wellcome Fund. Travel Grant: $2,950. PI: Robert L. Patrick.

1989-1990 Alcohol, Drug Abuse and Mental Health Administration (ADAMHA) Small Instrumentation Grant Program: $8,195. PI: Robert L. Patrick.

1992-1995 NIMH. Sigma Receptors and Dopamine Neurotransmission: $336,803. PI: J. Michael Walker, Psychology Department, Brown University; Co-Investigator: Robert L. Patrick.

1996-1999 National Institute on Drug Abuse (NIDA). Sigma Receptors and Dopamine Neurotransmission: $380,789. PI: J. Michael Walker, Psychology Department, Brown University; Co-Investigator: Robert L. Patrick.

1997-2000 National Institute on Drug Abuse (NIDA). Investigations of Precipitated Cannabinoid Withdrawal. $390,705. PI: J. Michael Walker, Psychology Department, Brown University; Co-Investigator: Robert L. Patrick.