4.2a Serotonin. Even though increased dopamine in the brain reward system is generally thought to be the final common pathway for the reinforcing properties of drugs, other neurotransmitters such as serotonin are involved in the modulation of both drug self-administration and dopamine levels.ike other drugs of abuse, stimulants increase dopamine concentrations in the brain reward pathway (1,2,3,4,7). Stimulants such as cocaine, amphetamines, caffeine and nicotine all stimulate the brain reward pathway through slightly different mechanisms and increase dopamine to different extents.
1 Gout is a form of arthritis caused by excess uric acid in the bloodstream. 2  The symptoms of gout are due to the formation of uric acid crystals in the joints. 3  Gout most commonly affects the joint in the base of the big toe.4  Gout attacks often occur without warning in the middle of the night.ore detail and supporting information is in the main article. 1  Gout is a form of arthritis caused by excess uric acid in the bloodstream. 2  The symptoms of gout are due to the formation of uric acid crystals in the joints.
Gout is caused by a build-up of a substance called uric acid in the blood. If you produce too much uric acid or your kidneys don't filter enough out, it can build up and cause tiny sharp crystals to form in and around joints. These crystals can cause the joint to become inflamed (red and swollen) and painful. Things that may increase your chances of getting gout include: