Migraine is a common, disabling problem with three phases: premonitory, main headache attack, and postdrome. The headache phase is thought to involve activation of trigeminal neurons, whereas the premonitory and postdrome phases may involve dopaminergic mechanisms. In animal studies, dopamine has been found to cause vasodilation of cranial arteries at very low doses. Using intravital microscopy...

The purpose of this study was to determine the mechanisms of dopamine regulation of phosphate uptake in opossum kidney (OK) cells, a model of proximal renal tubules. Dopamine stimulated cAMP generation and inhibited radiolabeled phosphate uptake into OK cell monolayers by 14.4 +/- 1.8%. The effect of dopamine was transient, as phosphate uptake returned toward control level by 3 h despite the co...

The interaction of dopaminergic antagonists with the D(1A) dopamine receptor was assessed in PC2 cells that transiently express this receptor. The maximal binding and dissociation constants for the D(1A) dopamine receptor, using the ligand [(125)I]SCH23982 were 0.38 +/- 0.09 nM and 1 to 4 pmol/mg, respectively, when assessed 48 h after transfection with cDNA encoding the rat D(1A) receptor. Bas...

In the striatum many neurotransmitters including GABA, glutamate, acetylcholine, dopamine, nitric oxide and adenosine interact to regulate synaptic transmission. Dopamine release in the striatum is regulated by a number of pre- and postsynaptic receptors including adenosine. We have recently shown using isolated rat striatal slices, and the technique of fast cyclic voltammetry, that adenosine A...

Extensive evidence suggests that the hypocretins/orexins influence cocaine reinforcement and dopamine signaling via actions at hypocretin receptor 1. By comparison, the involvement of hypocretin receptor 2 in reward and reinforcement processes has received relatively little attention. Thus, although there is some evidence that hypocretin receptor 2 regulates intake of some drugs of abuse, it is...

The present study demonstrates that repeated administration of SKF-38393, a D1-dopamine agonist, is necessary for maximal behavioral supersensitivity of D1-dopamine receptor responses in neonatal 6-OHDA-lesioned rats, confirming earlier work. This repeated administration of SKF-38393, which is referred to as priming of D1-dopamine receptor responses, resulted in a progressive increase in locomo...

Rats were treated for 21 d with the selective D1 dopamine receptor antagonist SCH23390, the selective D2 dopamine receptor antagonist spiperone, the nonselective dopamine receptor antagonist cis-flupentixol, or a combination of SCH23390 and spiperone. In addition, a group of rats received L-prolyl-L-leucyl-glycinamide (PLG) for 5 d after the 21 d chronic spiperone treatment. Chronic treatment w...

Circadian rhythm describes the physical, psychological, and behavioural patterns of living organisms that respond to day night light levels. The important bodily functions like hunger, sleep, gastrointestinal motility, mood, coordination, body temperature, gene transcription, sensory perceptions, sleep-wake cycles hormone release etc are influenced by circadian rhythm. Abnormal may result obesi...

GABA neurons of the cerebral cortex and other telencephalic structures are produced in the basal forebrain and migrate to their final destinations during the embryonic period. The embryonic basal forebrain is enriched in dopamine and its receptors, creating a favorable environment for dopamine to influence GABA neuron migration. However, whether dopamine receptor activation can influence GABA n...

BACKGROUND Dopamine signaling is mediated by Gs protein-coupled "D1-like" receptors (D1 and D5) and Gi-coupled "D2-like" receptors (D2-4). In asthmatic patients, inhaled dopamine induces bronchodilation. Although the Gi-coupled dopamine D2 receptor is expressed and sensitizes adenylyl cyclase activity in airway smooth muscle (ASM) cells, the Gs-coupled dopamine D1-like receptor subtypes have ne...