Cannabis contains numerous cannabinoids, the most common of which are tetrahydrocannabinol (THC) and cannabidiol (CBD). While all current antipsychotics work by interfering with the action of dopamine on dopamine D2 receptors, two recent reports showed that between 800 and 1000 mg of cannabidiol per day alleviate the signs and symptoms of schizophrenia, although cannabidiol is not known to act on dopamine receptors. The Lupica (Lupica and Riegel 200) model of the cannabinoid modulation of dopamine neuronal activity is also relevant in the context of endocannabinoid signaling.Endocannabinoids differ from classic neurotransmitters because they are formed and released on demand during periods of high neuronal activity (Freund et al. Therefore, during episodes of phasic dopamine, intracellular Ca2+ increases precipitously, activating enzymes (p.
ex. Once synthesized, endocannabinoids cross the plasma membrane to the extrasynaptic space, where they retrograde the CB1 receptors of the cannabinoids in the presynaptic terminals (Wilson and Nicoll, 200). It is known that the binding of endocannabinoids to the CB1 receptors of the presynaptic cannabinoid causes the suppression of GABA-mediated inhibition (Wilson and Nicoll 200), a form of synaptic plasticity known as the suppression of inhibition induced by depolarization (Alger and Kim 201). Within the ventral tegmental area, the suppression of inhibition induced by depolarization should theoretically cause a net disinhibition of dopamine neuronal activity (cf.
There is increasing evidence to suggest that 2-arachidonoylglycerol is the main endocannabinoid involved in mediating these forms of synaptic plasticity (Melis et al.Because of its shape, CBD cannot bind to the C1 and C2 receptors in the brain like THC does. It would be like trying to stick a square peg into a round hole. Therefore, instead of binding to receptors, CBD influences and communicates with neurons in a more indirect way. When THC binds to CB1 receptors in the brain, it can influence aspects such as mood, memory, concentration, sensation and perception of time.
Studies have shown that THC consumption also causes a short-term increase in dopamine levels in the brain, which activates the brain's reward system.Some theorize that this plays a role in the euphoria that is often associated with THC consumption. In several studies, CBD has been shown to help regulate the dopamine present in the brain, either increasing it or decreasing it accordingly. Studies have found that CBD can communicate with a variety of nervous system receptors, including dopamine receptors, opioid receptors, and serotonin receptors. For example, studies have found that CBD can alleviate pain, reduce inflammation, provide neuroprotection, and alleviate mental health problems such as depression and anxiety.This includes examining how different cannabinoids, including THC and CBD, have an impact on dopamine levels.
Current research suggests that the interaction of THC with dopamine may contribute to its psychoactive effects, while CBD's unique way of interacting with dopamine could one day allow doctors to use it as a treatment for certain medical conditions. In a model of stimulant addiction in rats, CBD reduced the likelihood of relapses, reduced anxiety levels, and improved levels of endocannabinoid and dopaminergic machinery in the brain.Studies indicate that the two main cannabinoids in cannabis, THC and CBD, have effects on dopamine levels in the body, although in markedly different ways. The various benefits derived from high-quality CBD are the result of the impact that CBD oil has on neurotransmitters in the body. Unlike THC, cannabidiol (CBD) cannot directly bind to the CB1 or CB2 receptors in the brain; its shape does not allow it.
Rather than binding to cannabinoid receptors, CBD seems to communicate with neurons in a more indirect way.While more research needs to be done to fully understand the connection between cannabis and dopamine, there seems to be some interesting interaction between dopamine, THC and CBD. Only future research on the effects of cannabis will reveal precisely how THC and CBD interact with dopamine, but it seems safe to say that cannabis and dopamine are inherently interconnected.