The two pathways marijuana uses to affect the brain is dopamine and THC. Dopamine is known to be a neurotransmitter, which is involved in controlling the brain’s sensational centers. It helps maintain movement and emotional responses, high levels of dopamine may raise your movement and emotional responses, which is affected by marijuana, while THC or also referred to as Tetrahydrocannabinol is one of the main contents of marijuana, it is considered to be a psychoactive essential ingredient in marijuana.