The dopamine receptors have been classified into two groups, the D1like and D2-like dopamine receptors, respectively, based on molecular biology and pharmacological studies. The D1-like dopamine receptors comprise the D1 and D5 dopamine receptors and the D2-like dopamine receptors include the D2, D3 and D4 dopamine receptors. The gene structures of these two classes of receptors are dissimilar ...

Whether amphetamine acts principally at the plasma membrane or at synaptic vesicles is controversial. We find that d-amphetamine injection into the Planorbis giant dopamine neuron causes robust dopamine release, demonstrating that specific amphetamine uptake is not required. Arguing for action at vesicles, whole-cell capillary electrophoresis of single Planorbis dopamine neurons shows that amph...

In eight mechanically ventilated patients in cardiogenic shock, we assessed the hemodynamic effects of an infusion of dopamine and dobutamine and evaluated its role in preventing the deleterious effects of administering each amine alone. Each patient received three infusions in a randomly assigned order: dopamine, 15 micrograms/kg/min; dobutamine, 15 micrograms/kg/min; and a combination of dopa...

Opiates, like other addictive drugs, elevate forebrain dopamine levels and are thought to do so mainly by inhibiting GABA neurons near the ventral tegmental area (VTA), in turn leading to a disinhibition of dopamine neurons. However, cholinergic inputs from the laterodorsal (LDT) and pedunculopontine (PPT) tegmental nucleus to the VTA and substantia nigra (SN) importantly contribute, as either ...

Dopamine is believed to contribute to the degeneration of dopamine-containing neurons in the brain. However, whether dopamine affects the survival of other neuronal populations has remained unclear. Here we document that mice with persistently elevated extracellular dopamine, resulting from inactivation of the dopamine transporter gene, sporadically develop severe symptoms of dyskinesia concomi...

Dopamine is thought to regulate learning from appetitive and aversive events. Here we examined how optogenetically-identified dopamine neurons in the lateral ventral tegmental area of mice respond to aversive events in different conditions. In low reward contexts, most dopamine neurons were exclusively inhibited by aversive events, and expectation reduced dopamine neurons' responses to reward a...

In the present study, interactive effects of D1 and D2 dopamine receptors antagonists and different periods of lithium pretreatment on morphine dependence in mice have been investigated. This study was designed to investigate whether the hypothesis that lithium and dopaminergic mechanisms via their effects on phosphoinositide pathways and calcium flux could influence morphine withdrawal respons...

20 Anatomical studies have demonstrated that the mesolimbic dopamine system receives a 21 substantial afferent input from a variety of regions ranging from the prefrontal cortex 22 through to the brainstem. However, how these afferents regulate dopamine neuron activity 23 is still largely unknown. The mesopontine tegmentum provides a significant input to ventral 24 tegmental area (VTA) dopamine...

PURPOSE Increased adrenergic activity in response to chronic stress is known to promote tumor growth by stimulating the tumor microenvironment. The focus of the current study was to determine whether dopamine, an inhibitory catecholamine, could block the effects of chronic stress on tumor growth. EXPERIMENTAL DESIGN Expression of dopamine receptors (DR1-DR5) was analyzed by reverse transcript...

The non-catechol, selective dopamine D2-agonist compound 3H-205-502 was used to localize dopamine D2 receptors by autoradiography after in vitro labeling of brain sections. The characteristics of the binding of this ligand to tissue sections were those expected from the labeling of dopamine D2 receptors. The binding of 3H-205-502 was inhibited selectively and stereospecifically by dopamine D2 a...