Marijuana craving in the brain

Abstract

Craving is one of the primary behavioral components of drug addiction, and cue-elicited craving is an especially powerful form of this construct. While cue-elicited craving and its underlying neurobiological mechanisms have been extensively studied with respect to alcohol and other drugs of abuse, the same cannot be said for marijuana. Cue-elicited craving for other drugs of abuse is associated with increased activity in a number of brain areas, particularly the reward pathway. This study used functional magnetic resonance imaging (fMRI) to examine cue-elicited craving for marijuana. Thirty-eight regular marijuana users abstained from use for 72 h and were presented with tactile marijuana-related and neutral cues while undergoing a fMRI scan. Several structures in the reward pathway, including the ventral tegmental area, thalamus, anterior cingulate, insula, and amygdala, demonstrated greater blood oxygen level dependent (BOLD) activation in response to the marijuana cue as compared with the neutral cue. These regions underlie motivated behavior and the attribution of incentive salience. Activation of the orbitofrontal cortex and nucleus accumbens was also positively correlated with problems related to marijuana use, such that greater BOLD activation was associated with greater number of items on a marijuana problem scale. Thus, cue-elicited craving for marijuana activates the reward neurocircuitry associated with the neuropathology of addiction, and the magnitude of activation of these structures is associated with severity of cannabis-related problems. These findings may inform the development of treatment strategies for cannabis dependence.cannabis ͉ cue ͉ fMRI ͉ reward

The cerebellum in drug craving

“…Traditionally, craving has been associated with brain areas related to reward, motivation and memory, including prefrontal cortical areas (Grant et al, 1996); the striatum and ventral pallidum (Filbey et al, 2009;Wetherill et al, 2013); mesolimbic dopamine structures such as the ventral tegmental area (Goudriaan et al, 2013); and reward memory areas like the amygdala or the hippocampus (Kilts et al, 2001;Volkow et al, 2004).…”

“…Numerous human neuroimaging studies have demonstrated activation in the cerebellum during the presentation of drug-associated cues (Anderson et al, 2006;Filbey et al, 2009;Grant et al, 1996). In almost every study, craving was elicited by the presentation of the cue.…”

“…Interestingly, activation of the cerebellum was a common finding in the aforementioned imaging studies (Anderson et al, 2006;Bonson et al, 2002;Filbey et al, 2009;Grant et al, 1996;Kilts et al, 2001;Smolka et al, 2006;Tomasi et al, 2015). However, this region has been habitually overlooked probably because of the firmly established view of the cerebellum as a region exclusively committed to motor-related functions.…”

“…The frontal zones involved in craving seem to be the anterior cingulate cortex, orbitofrontal cortex, dorsolateral prefrontal cortex, and the inferior frontal gyrus (Grant et al, 1996;Bonson et al, 2002). The 7 anterior cingulate cortex, a brain area related to self-control (Tang et al, 2015) and to rewardrelated cognitive processes (Shidara and Richmond, 2002) has been found to be active when drug-related cues are presented (Filbey et al, 2009;Myrick et al, 2004). Activity in the anterior cingulum seems to act as a predecessor of the onset of craving, being linked to the emotional response triggered by drug-related cues (Robbins et al, 2008;Wexler et al, 2001).…”

“…Subcortical activity during craving experience has been described in brain areas traditionally related to emotional memory and reward processing, including hippocampus (Volkow et al, 2004), amygdala (Kilts et al, 2001), and ventral striatum (Filbey et al, 2009). Dorsal striatal activity, which can be associated with habitual behavior and its maintenance (Everitt and Robbins, 2016), has been reported to predict cocaine craving (Volkow et al, 2006).…”