Humans and animals take actions quickly when they expect that the actions lead to reward, reflecting their motivation. Injection of dopamine receptor antagonists into the striatum has been shown to slow such reward-seeking behavior, suggesting that dopamine is involved in the control of motivational processes. Meanwhile, neurophysiological studies have revealed that phasic response of dopamine ...

Aberrant dopaminergic signaling is a critical determinant in multiple psychiatric disorders, and in many disease states, dopamine receptor number is altered. Here we identify a molecular mechanism that selectively targets D2 receptors for degradation after their activation by dopamine. The degradative fate of D2 receptors is determined by an interaction with G protein coupled receptor-associate...

Intravenous cocaine intake in laboratory animals is characterized by periods of apparent drug satiety between regularly spaced earned injections. The reinforcing properties of cocaine are linked primarily to dopaminergic neurotransmission in the shell and not the core of nucleus accumbens. To determine whether the satiating effects of cocaine are similarly mediated, we perfused dopamine recepto...

Reduction of wavelength discrimination ability in the 560-640 nm range, but not in the 404-540 nm range, has been demonstrated in goldfish after intravitreal injection of D1-dopamine receptor antagonists. Intravitreal injection of the dopaminergic neurotoxin 6-OH-dopamine severely reduced wavelength discrimination ability in the 540-661 nm range within 3 days. Discrimination ability could be re...

The present study examined whether unilateral stimulation of acetylcholine or dopamine receptors in the nucleus accumbens induces an asymmetry in dopamine transmission in the ventrolateral striatum. For this purpose, a microdialysis technique was used to measure dopamine release in both sides of the ventrolateral striatum following unilateral injections of carbachol (5 micrograms/0.5 microliter...

Aberrant neuregulin-1 (NRG1) signals are suggested to associate with the neuropathophysiology of schizophrenia. Employing a mouse schizophrenia model established by neonatal neuregulin-1 challenge, we analysed postpubertal consequence of the NRG1 pretreatment for the electrophysiological property of nigral dopamine neurons. In vivo single unit recordings from anaesthetized NRG1-pretreated mice ...

The temporal course of yawning behavior elicited by increasing doses of apomorphine (APO), from 0.01 to 10 mg/kg, was studied experimentally in adult albino rats. In the higher dose range a great prolongation of drug induced yawning latency is observed. This result is explainable by postulating differences in sensitivity of two sets of dopaminergic (DA) receptors: low threshold presynaptic DA r...

Pain is a multidimensional experience, which includes sensory, cognitive, and affective aspects. Converging lines of evidence indicate that dopaminergic neurotransmission plays an important role in human pain perception. However, the precise effects of dopamine on different aspects of pain perception remain to be elucidated. To address this question, we experimentally decreased dopaminergic neu...

A recent study of dopaminergic neurons in the brain of larval zebrafish has important implications for interpreting the natural actions of neuromodulators in the spinal cord.

Anticipation and delivery of rewards improves memory formation, but little effort has been made to disentangle their respective contributions to memory enhancement. Moreover, it has been suggested that the effects of reward on memory are mediated by dopaminergic influences on hippocampal plasticity. Yet, evidence linking memory improvements to actual reward computations reflected in the activit...