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 appears to come on suddenly, often in the form of a painfully swollen big toe or lower body joint. In reality, itâs the end result of a process thatâs been taking place in the body for a while. The underlying cause of gout is different from those things that trigger a gout attack. Gout is the result of excess uric acid in the body, a condition called hyperuricemia. Uric acid is a substance that normally forms when the body breaks down purines, which are found in human cells and in many foods. Uric acid is transported by the blood to the kidneys and eliminated in the urine.