NeurochemistryMarked decrease of immunolabelled 68 kDa neurofilament (NF-L) proteins in brains of opiate addictsGarcí-Sevilla, Jesús A.1,3,4; Ventayol, Pere3; Busquets, Xavier3; Harpe, Romano La2; Walzer, Claude1; Guimón, José1Author Information 1Department of Psychiatry, Faculty of Medicine, University of Geneva, Switzerland 2Institute of Forensic Medicine, Faculty of Medicine, University of Geneva, Switzerland 3Laboratory of Neuropharmacology, Department of Biology, University of the Balearic Islands, Cra. Valldemossa Km 7.5, E-07071 Palma de Mallorca (Balears), Spain 4Corresponding Author and Address: Jesús A. Garcí-Sevilla, Laboratory of Neuropharmacology, Department of Biology, University of the Balearic Islands, Cra. Valldemossa Km 7.5, E-07071 Palma de Mallorca (Balears), Spain ACKNOWLEDGEMENTS: This study was supported by grant 3100–043258.95 (J.G.) from the FNRS, Bern, Switzerland, and by grant PB 94-0002-Mod C (J.A.G.-S.) from DGICYT, Madrid, Spain. P.V. was supported by a fellowship from MEC (Madrid, Spain). We thank the staff members of the Institut Universitaire de Médecine Légale, Université de Genève, for their cooperation, and Dr Ch. Staub of the Unité de Toxicologie who supplied the toxicological data. J.A.G.-S. is a member of the Institut d'Estudis Catalans. Received 10 January 1997; accepted 6 March 1997 NeuroReport: May 6, 1997 - Volume 8 - Issue 7 - p 1561-1570 Buy Abstract NEUROFILAMENT (NF) proteins, the major components of the neuronal cytoskeleton, have been shown to represent previously unknown targets for the chronic effects of morphine in rats. This study was designed to evaluate the abundance of immunoreactive NF-L (68 kDa) proteins in post-mortem brains of chronic opiate addicts who had died of a heroin or methadone overdose. Levels of NF-L proteins were assessed by immunoblotting techniques. Levels of immunoreactive NF-L proteins were markedly decreased (47%, n = 17) in the frontal cortex. The reduced abundance of brain NF-L proteins was not related to the post-mortem delay or to the plasma concentrations of opiates, suggesting that the observed changes represent a specific long-term effect of opiate drugs. Because of the functions associated with NF proteins (e.g. axonal transport), this finding suggests that opiate drugs may induce neuronal damage after chronic abuse in humans. © Lippincott-Raven Publishers.