The endocannabinoid system is a crucial player in regulating nearly all physiological processes in the body, including the brain. It has been shown to be a primary regulator of dopamine neurotransmission, a major neurotransmitter in the brain, which are involved in cognitive, emotional, and motor aspects of goal-directed behavior. This 2017 scientific review highlights the existing knowledge on how the endocannabinoid system controls dopamine neuron function through modifications in synaptic strength at midbrain and striatal sites, suggesting these two systems are even more unified than previously thought.
The endocannabinoid system is a vast signaling network that controls synaptic transmission throughout the brain and periphery, and its interactions with the dopamine system are critical for several behaviors and neuropsychiatric disorders that were previously considered 'dopamine-dependent.' The review emphasizes the importance of the the endocannabinoid system in controlling dopamine neuron function and raises important questions on the subject.
Studies have shown that endocannabinoids play a critical role in regulating dopamine neurotransmission in the brain. They do this by filtering dopamine input from midbrain and forebrain regions, where they are processed and transmitted downstream. The endocannabinoid system acts locally at the midbrain and terminal regions, shaping how incoming information is processed by dopamine neurons and transmitted to output targets. It helps to control the firing patterns of dopamine cells, the release of dopamine, and its effects on the brain's synapses. Cannabinoid receptors in the brain modulate the strength of excitatory and inhibitory synapses, allowing them to control the release of neurotransmitters like dopamine.
The importance of the endocannabinoid system in regulating reward and motivation is further underscored by its involvement in drug reinforcement. Addictive drugs target the brain's reward circuits, leading to the release of dopamine and the hijacking of normal reward learning mechanisms. The endocannabinoid system plays a critical role in this process, with mounting evidence identifying it as an important conduit by which addictive drugs access brain reward circuits. By manipulating the endocannabinoid system, it may be possible to develop new therapies that can help to restore normal dopamine function in these disorders.
In conclusion, the endocannabinoid system is a crucial regulator of dopamine neurotransmission in the brain, affecting both midbrain and striatal sites. This review provides an important overview of the existing knowledge on the role of the endocannabinoid system in regulating dopamine neurotransmission, and highlights the importance of further research in this area for the development of potential therapies for neuropsychiatric disorders.
Study Title: Endocannabinoid modulation of dopamine neurotransmission
Study Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5608040