Antipsychotic drugs are extensively prescribed for the treatment of schizophrenia and other related psychiatric disorders. These drugs produced their action by blocking dopamine (DA) receptors, and these receptors are widely present throughout the brain. Therefore, extended antipsychotic use also leads to severe extrapyramidal side effects. The short-term effects include parkinsonism and the la...

The effects of putative retinal neurotransmitters and several neuropeptides on 3H-dopamine release from isolated perfused carp (Cyprinus carpio) retinas were studied. Of the transmitter candidates tested, only serotonin (5-HT) and the 5-HT agonist tryptamine released 3H-dopamine. However, the release evoked by these agents was calcium (Ca2+) independent and not blockable by the 5-HT antagonist ...

Acamprosate reduces the craving for alcohol by decreasing glutamate activity and increasing gamma-aminobutyric acid (GABA) action in patients with alcohol dependence. Acamprosate has tolerable side effects that include diarrhea, headache, dizziness and pruritus. In this study, we report acamprosate-induced extrapyramidal symptoms in an elderly patient with no history of neurologic disease. Seve...

Meige syndrome, which has been presented in tardive syndromes, is a form of blepharospasm accompanied by oromandibular dystonia with manifestations over the face, jaw, and neck. A blepharospasm can be induced by antihistamines, dopaminomimetic or sympathomimetic drugs, or long-term exposure to dopamine antagonists. Atypical antipsychotics have less extrapyramidal side effects because of a weak ...

This review addresses the relationship between modifications in membrane phospholipid composition (MPC) and alterations in dopaminergic, serotonergic and cholinergic neurotransmitter systems in schizophrenia. The main evidence in support of the MPC hypothesis of schizophrenia comes from post-mortem and platelet studies, which show that in schizophrenia, certain omega-3 and omega-6 polyunsaturat...

The dopamine hypothesis of schizophrenia is based on evidence that the major antipsychotic drugs act by blocking dopamine D2 receptors and that dopamine-releasing drugs worsen symptoms. In this issue of Neuron, Kellendonk et al. report an elegant conditional transgenic mouse overexpressing dopamine D2 receptors selectively in the striatum. Strikingly, these animals display selective cognitive i...

Dopamine receptors previously identified in corpora allata (CA) of Manduca sexta last instars on the basis of dopamine effects on JH (juvenile hormone)/JH acid biosynthesis and cyclic AMP (cAMP) accumulation, were characterized pharmacologically. For this study, a broad spectrum of agonists or antagonists of D1, D2, D3 or D4 dopamine receptors, together with the dopamine metabolite N-acetyl-dop...

The treatment pattern observed correlates with the worldwide changing trends in the treatment of schizophrenia. In recent years, the introduction of newer atypical antipsychotic agents like olanzapine, risperidone, quetiapine and ziprasidone have provided a better control of symptoms and reduced adverse effects especially the extrapyramidal ones in contrast with older drugs. The newer atypical ...

Repeated administration of antipsychotic drugs to normal rats has been shown to induce a state of dopamine neuron inactivation known as depolarization block, which correlates with the ability of the drugs to exhibit antipsychotic efficacy and extrapyramidal side effects in schizophrenia patients. Nonetheless, in normal rats depolarization block requires weeks of antipsychotic drug administratio...

In contrast to the conventional view of dopamine involvement in schizophrenia, which posits hyperactive dopaminergic transmission, we propose that for unknown developmental and/or biochemical reasons, a primary defect occurs in efficient, tight dopaminergic synaptic transmission, triggering feedback activation and receptor upregulation, and resulting in the well-characterized increase in dopami...