In postmortem studies of patients with schizophrenia, D2 dopamine receptors in the basal ganglia have been observed to be more numerous than in patients with no history of neurological or psychiatric disease. Because most patients with schizophrenia are treated with neuroleptic drugs that block D2 dopamine receptors in the caudate nucleus, it has been suggested that this increase in the number ...

Dopamine acts through two classes of G protein-coupled receptor (D1-like and D2-like) to modulate neuron activity in the brain. While subtypes of D1- and D2-like receptors are coexpressed in many neurons of the mammalian brain, it is unclear how signaling by these coexpressed receptors interacts to modulate the activity of the neuron in which they are expressed. D1- and D2-like dopamine recepto...

Abstract The ventral tegmental area (VTA) in the midbrain is important for food reward. High-fat containing palatable foods have reinforcing effects and accelerate obesity. We have previously reported that diet-induced obesity selectively decreased the spontaneous activity of VTA GABA neurons, but not dopamine neurons. The spontaneous activity of VTA dopamine neurons is regulated by D2 autorece...

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...

The activity patterns of subthalamic nucleus (STN) neurons are intimately related to motor function/dysfunction and modulated directly by dopaminergic neurons that degenerate in Parkinson's disease (PD). To understand how dopamine and dopamine depletion influence the activity of the STN, the functions/signaling pathways/substrates of D2-like dopamine receptors were studied using patch-clamp rec...

Chronic blockade or activation of dopamine receptors is critical for the pharmacological treatment of diseases like schizophrenia, Parkinson's or attention deficit and hyperactivity disorder. However, the long-term impact of such treatments on dopamine neurons is unclear. Chronic blockade of the dopamine D2 receptor in vivo triggers an increase in the axonal arborization of dopamine neurons [Eu...

D2-like dopamine autoreceptors regulate dopamine release and are implicated in important actions of antipsychotic drugs and rewarding behaviors. To directly observe the effects of D2 autoreceptors on exocytic neurotransmitter release, we measured quantal release of dopamine from pheochromocytoma PC12 cells that express D2 and D4 autoreceptors. High potassium-evoked secretion in PC12 cells produ...

ATTENUATION OF ANTAGONIST-INDUCED IMPAIRMENT IN DOPAMINE RECEPTOR ONTOGENY BY L-PROLYL-L-LEUCYL-GLYCINAMIDE by Mohamad Iqbal Saleh, M.D. It has been shown by others that the prenatal treatment of rats with haloperidol, a dopamine D2 receptor antagonist, leads to a permanent reduction in the number of striatal dopamine D2 receptors in adulthood. Conversely, postnatal treatment of lactating dams ...

Introduction: The protective and antisecretory effects of dopamine agonists on the stomach have been already reported, but the effect of bromocriptine (D2 dopamine agonist) on histamine stimulated gastric acid secretion (GAS) needs to be investigated. Methods: For gastric sampling, animals were anesthetized and a polyethylen tube was introduced into the stomach through esophagus. A cannula ...