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:
“No further evidence is needed to show that “mental illness” is not the name of a biological condition whose nature awaits to be elucidated, but is the name of a concept whose purpose is to obscure the obvious.”
—Thomas Szasz (b. 1920)
“Certainly parents play a crucial role in the lives of individuals who are intellectually gifted or creatively talented. But this role is not one of active instruction, of teaching children skills,... rather, it is support and encouragement parents give children and the intellectual climate that they create in the home which seem to be the critical factors.”
—David Elkind (20th century)
“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)