Attenuated frontal and sensory inputs to the basal ganglia in cannabis users
Addiction Biology March 3, 2016 Laura Blanco‐Hinojo, Jesus Pujol, Ben J. Harrison et al. 52 citations
Chronic cannabis use is associated with reduced motivation, and this study examined how it affects functional connectivity between the basal ganglia and brain regions involved in internal (frontal cortex) and external (sensory cortices) motivation signals. Resting-state fMRI in 28 chronic cannabis users and 29 controls showed that cannabis exposure attenuated the positive correlation between the striatum and limbic frontal-basal ganglia circuits, and attenuated the negative correlation between the striatum and the fusiform gyrus, which is important for recognizing significant visual features. These connectivity alterations were linked to lower arousal in response to affective pictures. Changes tended to normalize after one month of abstinence, indicating that cannabis impairs fine-tuning of the motivation system, but this effect is reversible.