Target type: biologicalprocess
The regulated release of dopamine from the somatodendritic compartment (cell body or dendrites) of a neuron. [GOC:bf, GOC:PARL, PMID:21576241]
Somato-dendritic dopamine secretion is a specialized form of neurotransmitter release that occurs in dopaminergic neurons, particularly those in the substantia nigra and ventral tegmental area. Unlike the conventional axonal release, which involves vesicles traveling down the axon to the synapse, this process allows for dopamine release directly from the soma and dendrites of the neuron.
The process begins with the synthesis of dopamine within the neuron. Dopamine is produced from the precursor L-dopa through the action of the enzyme tyrosine hydroxylase. Once synthesized, dopamine is packaged into synaptic vesicles.
In somato-dendritic secretion, these vesicles are transported to the soma and dendrites, where they accumulate near the plasma membrane. These sites are often characterized by the presence of specialized release sites known as "non-synaptic" or "extra-synaptic" sites, distinct from the traditional synaptic terminals.
Dopamine release from these sites is triggered by a variety of stimuli, including neuronal activity, calcium influx, and neurotransmitter interactions. These stimuli can activate different signaling pathways and ultimately lead to the fusion of the dopamine-filled vesicles with the plasma membrane, releasing dopamine into the extracellular space.
Somato-dendritic dopamine secretion is believed to play several important roles in brain function. It is thought to contribute to:
- **Dopaminergic autoreceptor modulation:** Dopamine released from the soma and dendrites can activate dopamine receptors on the same neuron, regulating its own release and activity.
- **Volume transmission:** Dopamine released from non-synaptic sites can diffuse over relatively long distances, affecting a wider population of neurons compared to traditional synaptic transmission.
- **Plasticity and learning:** Somato-dendritic dopamine release may play a role in synaptic plasticity and learning, potentially contributing to the modulation of neuronal circuits.
While the exact mechanisms of somato-dendritic dopamine secretion are still being investigated, it is clear that this process represents a unique and important form of neurotransmitter release in the brain. It contributes to the complex signaling dynamics within dopaminergic circuits, influencing diverse aspects of brain function.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Synaptic vesicular amine transporter | A synaptic vesicular amine transporter that is encoded in the genome of cow. [OMA:Q27963, PRO:DNx] | Bos taurus (cattle) |
| Synaptic vesicular amine transporter | A synaptic vesicular amine transporter that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q05940] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| ketanserin | ketanserin : A member of the class of quinazolines that is quinazoline-2,4(1H,3H)-dione which is substituted at position 3 by a 2-[4-(p-fluorobenzoyl)piperidin-1-yl]ethyl group. Ketanserin: A selective serotonin receptor antagonist with weak adrenergic receptor blocking properties. The drug is effective in lowering blood pressure in essential hypertension. It also inhibits platelet aggregation. It is well tolerated and is particularly effective in older patients. | aromatic ketone; organofluorine compound; piperidines; quinazolines | alpha-adrenergic antagonist; antihypertensive agent; cardiovascular drug; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; serotonergic antagonist |
| reserpine | reserpine : An alkaloid found in the roots of Rauwolfia serpentina and R. vomitoria. Reserpine: An alkaloid found in the roots of Rauwolfia serpentina and R. vomitoria. Reserpine inhibits the uptake of norepinephrine into storage vesicles resulting in depletion of catecholamines and serotonin from central and peripheral axon terminals. It has been used as an antihypertensive and an antipsychotic as well as a research tool, but its adverse effects limit its clinical use. | alkaloid ester; methyl ester; yohimban alkaloid | adrenergic uptake inhibitor; antihypertensive agent; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; environmental contaminant; first generation antipsychotic; plant metabolite; xenobiotic |
| tetrabenazine | 9,10-dimethoxy-3-isobutyl-1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a]isoquinolin-2-one : A benzoquinolizine that is 1,2,3,4,4a,9,10,10a-octahydrophenanthrene in which the carbon at position 10a is replaced by a nitrogen and which is substituted by an isobutyl group at position 2, an oxo group at position 3, and methoxy groups at positions 6 and 7. | benzoquinolizine; cyclic ketone; tertiary amino compound | |
| 2h-benzo(a)quinolizin-2-ol, 2-ethyl-1,3,4,6,7,11b-hexahydro-3-isobutyl-9,10-dimethoxy- | 2H-Benzo(a)quinolizin-2-ol, 2-Ethyl-1,3,4,6,7,11b-hexahydro-3-isobutyl-9,10-dimethoxy-: Proposed catecholamine depletor. | ||
| reserpic acid | reserpic acid: inhibitor of norepinephrine transport into chromaffin vesicle ghosts; RN given refers to (3beta,16beta,17alpha,18beta,20alpha)-isomer parent cpd; structure given in first source | yohimban alkaloid | |
| lobeline | (-)-lobeline : An optically active piperidine alkaloid having a 2-oxo-2-phenylethyl substituent at the 2-position and a 2-hydroxy-2-phenylethyl group at the 6-position. | aromatic ketone; piperidine alkaloid; tertiary amine | nicotinic acetylcholine receptor agonist |
| dihydrotetrabenazine | dihydrotetrabenazine: RN given refers to cpd without isomeric designation | isoquinolines | |
| lobeline | |||
| lobelane | lobelane: structure in first source | ||
| mrk 560 | MRK 560: a gamma-secretase inhibitor; MRK-560 is the (cis)-isomer; structure in first source |