Chapter 14 Opener State initiatives such as the 2012 Oregon Cannabis Tax Act are aimed at decriminalizing or even legalizing the possession and use of small amounts of cannabis Figure 14.1 Poster advertising the 1936 film Reefer Madness Figure 14.2 Cannabis plants Figure 14.3 The potent form of cannabis called hashish Figure 14.4 An 8000-year time line of cannabis use around the world Figure 14.5 Chemical structure of 9-tetrahydro-cannabinol (THC) Figure 14.6 Mean time course of plasma THC concentrations Figure 14.7 Autoradiogram of a horizontal section through a rat brain Figure 14.8 Hippocampal CB1 receptors are responsible for memory impairment Figure 14.9 Chemical structures of the endocannabinoids anandamide and 2-arachidonoylglycerol (2-AG) Figure 14.10 Retrograde signaling by endocannabinoids Box 14.1, Figure A CB1 receptors are widely expressed in the neural circuitry of the human brain that regulates mood Figure 14.11 Food intake and body weight gain are reduced in rats Figure 14.12 Role of the endocannabinoid system in extinction of auditory fear conditioning Figure 14.12 Role of the endocannabinoid system in extinction of auditory fear conditioning (Part 1) Figure 14.12 Role of the endocannabinoid system in extinction of auditory fear conditioning (Part 2) Figure 14.13 Reduction in the subjective and physiological effects of smoked marijuana Figure 14.14 Time course of plasma THC concentrations Figure 14.14 Time course of plasma THC concentrations (Part 1) Figure 14.14 Time course of plasma THC concentrations (Part 2) Figure 14.15 Oral THC produces a dose-dependent impairment in explicit memory Figure 14.16 Acquisition of THC self-administration by squirrel monkeys Figure 14.17 Probability of initiating marijuana use as a function of age Figure 14.18 Trajectories of marijuana use from the adolescent period to approximately age 37 Figure 14.19 Desensitization of cannabinoid receptors produced by chronic THC exposure Figure 14.20 Time course of overall withdrawal discomfort in heavy marijuana users undergoing abstinence Figure 14.21 Time course of relapse to first marijuana use after the first 30 days of treatment Box 14.2, Figure A Increased probability of developing psychosis in heavy cannabis users