Biological Role and Disorders
The rate at which DAT removes dopamine from the synapse can have a profound effect on the amount of dopamine in the cell. This is best evidenced by the severe cognitive deficits, motor abnormalities, and hyperactivity of mice with no dopamine transporters. These characteristics have striking similarities to the symptoms of ADHD.
Differences in the functional VNTR have been identified as risk factors for bipolar disorder and ADHD. Data has emerged that suggests there is also an association with stronger withdrawal symptoms from alcoholism, although this is a point of controversy. Interestingly, an allele of the DAT gene with normal protein levels is associated with non-smoking behavior and ease of quitting. Additionally, male adolescents particularly those in high-risk families (ones marked by a disengaged mother and absence of maternal affection) who carry the 10-allele VNTR repeat show a statistically significant affinity for antisocial peers.
Increased activity of DAT is associated with several different disorders, including clinical depression. Decreasing levels of DAT expression are associated with aging, and likely underlie a compensatory mechanism for the decreases in dopamine release as a person ages.
Read more about this topic: Dopamine Transporter
Famous quotes containing the words biological, role and/or disorders:
“It is not the literal past that rules us, save, possibly, in a biological sense. It is images of the past.... Each new historical era mirrors itself in the picture and active mythology of its past or of a past borrowed from other cultures. It tests its sense of identity, of regress or new achievement against that past.”
—George Steiner (b. 1929)
“The Declaration [of Independence] was not a protest against government, but against the excess of government. It prescribed the proper role of government, to secure the rights of individuals and to effect their safety and happiness. In modern society, no individual can do this alone. So government is not a necessary evil but a necessary good.”
—Gerald R. Ford (b. 1913)
“It no longer makes sense to speak of “feeding problems” or “sleep problems” or “negative behavior” is if they were distinct categories, but to speak of “problems of development” and to search for the meaning of feeding and sleep disturbances or behavior disorders in the developmental phase which has produced them.”
—Selma H. Fraiberg (20th century)