Unresponsiveness to Cannabinoids and Reduced Addictive Effects of Opiates in CB1 Receptor Knockout Mice Ledent, Catherine ; Valverde, Olga ; Cossu, Gregorio ; Petitet, Francois ; Aubert, Jean-Francois ; Beslot, Francoise ; Bohme, Georg A. ; Imperato, Assunta ; Pedrazzini, Thierry ; Roques, Bernard P. ; Vassart, Gilbert ; Fratta, Walter ; Parmentier, Marc Abstract Publication: Science Pub Date: January 1999 DOI: 10.1126/science.283.5400.401 Bibcode: 1999Sci...283..401L