Medicine and Health Sciences Commons^™

Expectation Modulates Human Brain Responses To Acute Cocaine: A Functional Magnetic Resonance Imaging Study, Peter Kufahl, Zhu Li, Robert C. Risinger, Charles Rainey, Linda B. Piacentine, Gaohong Wu, Alan S. Bloom, Zheng Yang, Shi-Jiang Li

College of Nursing Faculty Research and Publications

Background

Human expectation of psychoactive drugs significantly alters drug effects and behavioral responses. However, their neurophysiological mechanisms are not clear. This study investigates how cocaine expectation modulates human brain responses to acute cocaine administration.

Methods

Twenty-six right-handed non–treatment-seeking regular cocaine abusers participated in this study. Changes in blood oxygenation level-dependent (BOLD) signals were measured, and online behavioral ratings during cocaine expectation and acute cocaine administration were recorded.

Results

Distinct regional characteristics in BOLD responses to expected and unexpected cocaine infusions were observed in the medial orbitofrontal gyrus (Brodmann area [BA] 11), frontal pole (BA 10), and anterior cingulate gyrus regions. …

Stressor- And Corticotropin Releasing Factor-Induced Reinstatement And Active Stress-Related Behavioral Responses Are Augmented Following Long-Access Cocaine Self-Administration By Rats, John R. Mantsch, David A. Baker, David M. Francis, Eric S. Katz, Michael A. Hoks, Joseph P. Serge

Biomedical Sciences Faculty Research and Publications

Rationale Stressful events during periods of drug abstinence likely contribute to relapse in cocaine-dependent individuals. Excessive cocaine use may increase susceptibility to stressor-induced relapse through alterations in brain corticotropin-releasing factor (CRF) responsiveness.

Objectives This study examined stressor- and CRF-induced cocaine seeking and other stress-related behaviors in rats with different histories of cocaine self-administration (SA).

Materials and methods Rats self-administered cocaine under short-access (ShA; 2 h daily) or long-access (LgA; 6 h daily) conditions for 14 days or were provided access to saline and were tested for reinstatement by a stressor (electric footshock), cocaine or an icv injection of CRF and …