COGNITIVE NEUROSCIENCEHeroin-induced neuronal activation in rat brain assessed by functional MRIXu, Haiyun1; Li, Shi-Jiang1,3; Bodurka, Jerzy1; Zhao, Xiaoli1; Xi, Zheng Xiong2; Stein, Elliot A.1Author Information 1Biophysics Research Institute, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA 2Department of Psychiatry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA 3Corresponding Author: Shi-Jiang Li Acknowledgements: Authors wish to thank Drs Antal Hudetz and Hui Shen for valuable discussion, and Ms Hollis Brunner for editorial assistance. This work was supported by National Institutes of Health grant DA10124 (S.J.L.). Received 5 January 2000; accepted 28 January 2000 NeuroReport: April 7, 2000 - Volume 11 - Issue 5 - p 1085-1092 Buy Abstract The present study demonstrates the application of fMRI technology to neuropharmacology and the interaction of drug/receptor in the rat brain. Specifically, we have observed two different types of fMRI signal changes induced by acute i.v. heroin administration in rat brains under conditions of spontaneous and artificial respiration. Under spontaneous respiration, a global decrease in fMRI signal was observed; under artificial respiration, a region-specific increase in fMRI signal was identified and the activation sites are consistent with the distribution of opiate μ-receptors in rat brain as previously reported by autoradiography. Both heroin-induced fMRI signal changes were suppressed by pretreatment of naloxone, an opiate μ-receptor antagonist, and reversed by injection of naloxone following heroin infusion. These results suggest that fMRI has specific advantages in spatial and temporal resolution for studies of neuropharmacology and drugs of abuse. © 2000 Lippincott Williams & Wilkins, Inc.