Some teens' marijuana use has been linked to disrupted communication between two key regions in the brain’s reward circuitry at age 20. Disrupted communication between the regions was associated with poorer psychosocial functioning at age 22.
People with cannabis dependence have changes in neural circuitry in brain regions related to reward processing, habit formation, and psychopathology. These changes in neural circuitry may provide a useful marker for tracking psychopathology associated with cannabis misuse.
Cocaine produces a portion of its rewarding effects by increasing levels of granulocyte-colony stimulating factor (G-CSF) in the brain’s reward center. Treatments that prevent G-CSF signaling in the nucleus accumbens might reduce motivation to use cocaine.
October 2017 High-frequency electrical stimulation of neurons deep in the brain can reduce rats’ relapse-like behavior and motivation to take heroin. The finding strengthens hope that deep brain stimulation might offer a new treatment alternative for opioid addiction, particularly for patients who have not benefited from other treatments.
This research traced the effects of cocaine-induced disruption of serotonin regulation in the ventral pallidum and orbitofrontal cortex. The findings suggest that these effects may contribute to drug-seeking and cocaine-associated cognitive impairments.
Rats with a disrupted transcription factor 7-like 2 (Tcf7l2) gene in the medial habenula showed markedly greater nicotine intake than control rats. Reduced Tcf7l2 expression in the medial habenula reduced the normally observed increase in blood sugar in response to nicotine.