Serotonin is implicated in the regulation of complex sensory, motor, affective, and cognitive functions. However, the biochemical mechanisms whereby this neurotransmitter exerts its actions remain largely unknown. DARPP-32 (dopamine- and cAMP-regulated phosphoprotein of molecular weight 32,000) is a phosphoprotein that has primarily been characterized in relation to dopaminergic neurotransmissi...

In rat prefrontal cortex (the prelimbic area of medial frontal cortex), the induction of long-term depression (LTD) and long-term potentiation (LTP) of glutamatergic synapses is powerfully modulated by dopamine. The presence of dopamine in the bathing medium facilitates LTD in slice preparations, whereas in the anesthetized intact brain, dopamine released from dopaminergic axon terminals in the...

The prefrontal cortex (PFC) is crucial for maintaining relevant information in working memory and resisting interference. PFC neurons are strongly regulated by dopamine, but it is unknown whether dopamine receptors are involved in protecting target memories from distracting stimuli. We investigated the prefrontal circuit dynamics and dopaminergic modulation of targets and distractors in monkeys...

Dopamine (DA) is one of the main catecholamines in the brain and is crucial for movement coordination, endocrine function, reward, mood, memory and emotions. The dopaminergic system is the primary therapeutic target in the treatment of Parkinson’s disease (PD), drug addiction and schizophrenia. Notwithstanding, dysfunction of central dopaminergic neurotransmission has also been associated to de...

Young mice challenged with the neurotoxin 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP), which selectively destroys the substantia nigra dopaminergic neurons in the midbrain, exhibit spontaneous recovery of dopaminergic nerve terminals. However, such recovery becomes attenuated with age. Here we report that newly sprouted fibers originate from spared dopaminergic neurons in the ventral t...

Two families of G protein-coupled receptors of the neurotransmitter dopamine, i.e., dopamine 1-like family (D1-like receptor) and dopamine 2-like family (D2-like receptor), show dopaminergic activity in nerve cells. The D2-like receptor family, composed of D2, D3, and D4 receptors, downregulates the intracellular cAMP signaling pathway, and dopamine receptor agonists reduce the cAMP level in ne...

Dextromethorphan, a noncompetitive blocker of N-methyl-D- aspartate (NMDA) type of glutamate receptor, at 7.5-75 mg/kg, ip did not induce oral stereotypies or catalepsy and did not antagonize apomorphine stereotypy in rats. These results indicate that dextromethorphan at 7.5-75 mg/kg does not stimulate or block postsynaptic striatal D2 and D1 dopamine (DA) receptors. Pretreatment with 15 and 30...

Putative dopaminergic (pDAergic) ventral tegmental area neurons play an important role in brain pathways related to addiction. Extended exposure of pDAergic neurons to moderate concentrations of dopamine (DA) results in a time-dependent decrease in sensitivity of pDAergic neurons to DA inhibition, a process called dopamine inhibition reversal (DIR). We have shown that DIR is mediated by phospho...

Dopamine has been implicated in the modulation of working memory via its interactions with circuits located in the prefrontal cortex of rodents and non-human primates. However, the role that pathways triggered by dopamine receptor subtypes play in affecting processes of working memory remains unclear. In humans, the evidence for dopaminergic modulation of working memory is controversial and the...

The primate cortex represents and produces events in a distributed way, which calls for a mechanism that integrates their features into coherent structures. Visuomotor integration seems to be driven by dopaminergic (DA) pathways but which subsystems are involved is currently unknown. The present study compared the impact of the recreational use of two drugs on visuomotor integration: cannabis, ...