Dopamine long term control

Luetje CW, Patrick J (1991) Both alpha- and beta-subunits contribute to the agonist sensitivity of neuronal nicotinic acetylchohne receptors. J Neurosci 11 837-845 MameU-EngvaU M, Evrard A, Pons S, Maskos U, Svensson TH, Changeux JP, Faure P (2006) Hierarchical control of dopamine neuron-firing patterns by nicotinic receptors. Neuron 50 911-921 Mansvelder HD, McGehee DS (2000) Long-term potentiation of excitatory inputs to brain reward areas by nicotine. Neuron 27 349-357... 

Administration of levodopa plus carbidopa (or benserazide) remains the most effective treatment, but does not provide benefit beyond 3-5 y and is followed by gradual loss of symptom control, on-off fluctuations, and development of orobuccofacial and limb dyskinesias. These long-term drawbacks of levodopa therapy may be delayed by early monotherapy with dopamine receptor agonists. Treatment of advanced disease requires the combined administration of antiparkinsonian agents. 

Even when effective in controlling behavior, Ritalin and other stimulants have side effects common with use of amphetamines. These include nervousness, insomnia, and perhaps some more long-term problems such as dependency, slowed growth, or depression. Critics sometimes note the similarity between cocaine and the active chemical ingredient in Ritalin, methylphenidate. Both stimulate the dopamine system of the brain, but cocaine does so quickly and methylphenidate does so slowly. The similarities show in the abuse of Ritalin for its pleasure-inducing qualities. 

All the pharmacological and behavioural effects elicited by dopamine agonists and antagonists in the brain can only be explained if such an interaction occurs at the level of the dopamine receptor (D2 receptor site) the site still remains in search of a function. Bovine parathyroid cells were reported to possess dopamine sites which should be involved in the control of parathormone secretion. However, the very poor pharmacological characterization and the lack of in vivo evidence do not allow to assess the dopaminergic nature of this hormone secretion. Dopamine-sensitive adenylate cyclase is thus not a receptor directly implicated in the dopaminergic neurotransmission it is an enzyme which could have an important role in the control of long term metabolic effects such as the synthesis of neuronal constituents. 

Haloperidol is a phenylbutylpiperadine derivative antipsychotic, apparently cansed by dopamine-receptor blockage in CNS. It is indicated in the management of psychotic disorders control of Tonrette s disorder in children and adults management of severe behavioral problems in children short-term treatment of hyperactive children and long-term antipsychotic therapy (haloperidol decanoate). 

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