مختصر البحث:
Dopamine (DA) is the predominant catecholamine neurotransmitter in the
mammalian brain, where it controls a variety of functions including locomotor
activity, cognition, emotion, positive reinforcement, food intake, and endocrine
regulation. T…
Dopamine (DA) is the predominant catecholamine neurotransmitter in the
mammalian brain, where it controls a variety of functions including locomotor
activity, cognition, emotion, positive reinforcement, food intake, and endocrine
regulation. This catecholamine also plays multiple roles in the periphery as a
modulator of cardiovascular function, catecholamine release, hormone secretion,
vascular tone, renal function, and gastrointestinal motility[1]
.
The dopaminergic systems have been the focus of much research over the past 30
years, mainly because several pathological conditions such as Parkinson's disease,
schizophrenia, Huntington’s disease (HD), and Addiction. Dopamine receptor
antagonists have been developed to block hallucinations and delusions that occur in
schizophrenic patients, whereas DA receptor agonists are effective in alleviating the
hypokinesia of Parkinson's disease. However, blockade of DA receptors can induce
extrapyramidal effects similar to those resulting from DA depletion, and high doses of
DA agonists can cause psychoses. The therapies of disorders resulting from DA
imbalances are thus associated with severe side effects. Increased activity of brain
dopamine (DA) induces euphoria and approach motivation, while decreased DA
activity induces dysphoria and withdrawal-like conditions[2,3]. This view of DA’s
functions has been derived, in part ,from research on drugs of abuse, and thus DA is
thought to play a key role in reward action of abused drugs [4,5]. In addition, DAergic
dysfunction has been implicated in affective disorders[6,7]
