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Unformatted text preview: or no cannabinoid receptors in the dopaminergic neurons
of the ventral tegmental area (the reward pathway)
- However, marijuana does activate central reward
pathways, leading to dopamine release in the nucleus
- Therefore, marijuana’s effect on the reward system are
indirect THC causes DA release in the NAc THC decreases GABA inhibition of VTA neurons.
Therefore, increased firing of DA neuron and increased release
into the nucleus accumbens.
How might this system affect natural rewards? Endocannabinoids and Appetite
Endocannabinoids Mechanism of Action – Cannabidiol
• While THC is the predominant psychoactive component in
cannabis, the other chemicals can modify its effects.
• Cannabidiol (CBD) is a CB1/2 antagonist, and prevents THC
• CBD is also a serotonin receptor agonist, giving it antidepressant effects.
• Marijuana that has higher CBD:THC ratio (Indica as opposed
to Sativa) produce less anxiety and are more sedating.
• Pure CBD can relieve nausea, convulsions, anxiety, and
may be a potent anti-cancer agent by turning off cancer
genes or by stimulating the immune system to kill cancerous
cells in our bodies.
cells Medical Uses
• Marijuana (where legal) or Marinol (synthetic THC)
• Treatment of nausea and vomiting from drug treatment
in cancer and HIV/AIDS patients
- used when conventional drugs fail
• Tolerance to cannabinoids does develop, but
many users do not notice it at first
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- Fall '08