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The motor functions of dopamine are linked to a separate pathway, with cell bodies in the substantia nigra that manufacture and release dopamine into the dorsal striatum. Inside the brain, dopamine plays important roles in executive functions , motor control , motivation , arousal , reinforcement , and reward , as well as lower-level functions ...
Dopaminergic cell groups, DA cell groups, or dopaminergic nuclei are collections of neurons in the central nervous system that synthesize the neurotransmitter dopamine. [1] In the 1960s, dopaminergic neurons or dopamine neurons were first identified and named by Annica Dahlström and Kjell Fuxe , who used histochemical fluorescence . [ 2 ]
The latter was thus demonstrated to be an autoreceptor on cells that release dopamine. TAAR1 is a presynaptic intracellular receptor that is also colocalized with DAT and which has the opposite effect of the D2 autoreceptor when activated; [ 15 ] [ 24 ] i.e., it internalizes dopamine transporters and induces efflux through reversed transporter ...
The substantia nigra is located in the ventral midbrain of each hemisphere. It has two distinct parts, the pars compacta (SNc) and the pars reticulata (SNr). The pars compacta contains dopaminergic neurons from the A9 cell group that forms the nigrostriatal pathway that, by supplying dopamine to the striatum, relays information to the basal ganglia.
The dopamine neurons of the dopaminergic pathways synthesize and release the neurotransmitter dopamine. [2] [3] Enzymes tyrosine hydroxylase and dopa decarboxylase are required for dopamine synthesis. [4] These enzymes are both produced in the cell bodies of dopamine neurons. Dopamine is stored in the cytoplasm and vesicles in axon terminals.
The release of dopamine from the mesolimbic pathway into the nucleus accumbens regulates incentive salience (e.g. motivation and desire for rewarding stimuli) and facilitates reinforcement and reward-related motor function learning; [3] [4] [5] it may also play a role in the subjective perception of pleasure.
The most common drugs of abuse stimulate the release of dopamine, which creates both their rewarding and the psychomotor effects. Compulsive drug-taking behaviors are a result of the long-lasting or permanent [ 30 ] [ 31 ] functional changes in the mesolimbic dopamine system arising from repetitive dopamine stimulation.
The adrenal medulla is the principal site of the conversion of the amino acid tyrosine into the catecholamines; epinephrine, norepinephrine, and dopamine. Because the ANS, specifically the sympathetic division, exerts direct control over the chromaffin cells, the hormone release can occur rather quickly. [2]