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Leonard L. Howell, PhD

Psychiatry and Behavioral Sciences and Pharmacology

Division of Neuropharmacology and Neurologic Diseases

Director, Imaging Center
Yerkes National Primate Research Center

Phone: 404-727-7786


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Leonard Howell, PhD, studies behavioral neuro­pharmacology with a focus on central nervous system stimulants and the development of medications to treat stimulant addiction. Dr. Howell’s ongoing studies at the Yerkes Research Center investigate nonhuman primate models of the neurochemical mechanisms that mediate drug effects on behavior. Recent efforts have focused on drug-induced changes in brain neurochemistry with in vivo microdialysis in behaving monkeys trained to self-administer cocaine.  

As Chief of the Division of Neuropharmacology and Neurologic Disease, Dr. Howell oversees the administrative functions of the division. This entails oversight of the administrative staff, approving grant submissions by division faculty and trainees, ensuring appropriate allocation of division resources and mentoring junior faculty. Dr. Howell is involved in reporting division research activities to the National Center for Research Resources (NCRR) and preparing progress and plan descriptions of division research activities for the Yerkes Research Center’s P51 base grant renewal. Dr. Howell also serves as the liaison between division staff and the Yerkes administration, and advises the director on issues related to the scientific mission of the Center.

In addition, Dr. Howell serves as Director of the Yerkes Imaging Center. His neuroimaging program includes drug receptor occupancy, pharmacokinetics, brain metabolism and functional magnet resonance imaging (fMRI) in awake, behaving monkeys. The long-range goal is to develop a unique, multidisciplinary research program in substance abuse that effectively integrates behavior, neurochemistry and functional brain imaging in nonhuman primates.

Dr. Howell collaborates with a number of researchers at Yerkes, including Drs. Jocelyne Bachevalier, Heather Kimmel, Mike Kuhar, Chris Muly, Mar Sanchez, Kerry Ressler, Yoland Smith, Mark Wilson and Xiaodong Zhang.