Dopaminergic neuron
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Dopaminergic neuron
Dopaminergic neuron is a neuron that releases dopamine as a neurotransmitter found in a wide variety of animals, including both vertebrates and invertebrates.
• 1 Dopaminergic neuron • 2 Anatomy • 3 Molecular profile • 4 Physiology • 5 Behavior • 6 References • 7 Additional information
Dopaminergic neurons are located in the midbrain. In the mammalian central nervous system they are the main source of dopamine (DA). Dopaminergic neurons play an important role in the control of multiple brain functions including voluntary movement and a broad array of behavioral processes such as mood, reward, addiction, and stress. In addition they play a role in the regulation of emotion, severely affected in Parkinson’s disease.
Neuronal Type: Autonomic Neuron
Anatomy
The Dopaminergic neuron is an autonomic neuron derived from the neuron neural crest.The dopaminergic stimulations of the forebrain of mammals is constituted by a small number of highly collateralized neurons (~15,000 – 20,000 on each side of the rat brain) residing in the ventral mesencephalon. Three major divisions of dopaminergic pathways innervate the forebrain and basal ganglia These mesencephalic cell groups are specified as A8, A9, and A10, according to the nomenclature and generally correspond to the DA cells of the substantia nigra, ventral tegmental region and the retrorubral area (A8).• The dopaminergic innervation of the forebrain of mammals is constituted by a small number of highly collateralized neurons (~15,000 – 20,000 on each side of the rat brain) residing in the ventral mesencephalon. A dopminergic neuron’s axon can originate from a primary dendrite rather than straight from the soma.
Molecular profile
• Neurotransmitter: Dopamine
• Unique molecular markers:
Dopaminergic receptors are G-protein-coupled receptors (GPCRs), with 7 trans-membrane regions. GPCRs are in essence sluggish, metabotropic receptors that functionally alter other receptor systems and/or ion channels.
Physiology
The DA neurons are a component of a pathway that controls reward-seeking. DA neurons are the key cells altered in Parkinson's Disease and addiction. The DA neuron firing pattern is effected by changes in the quantity of dopamine and other neurotransmitters, as seen with drug abuse for example. Psychostimulants (e.g., cocaine, amphetamine and ephedrine) modify interactions amid several receptor subtypes that are co-expressed on DA neurons. Modifications in DA neuron activity trivial to altered receptor interactions may trigger several of the behavioral changes connected with drug addiction separately of natural reward seeking processes like feeding.
Behavior
Dopamine regulates the flow of information coming in from other regions of the brain after it enters the frontal lobe. A shortage or problem with the flow of dopamine can cause a person to lose the capability to think reasonably, revealed in schizophrenia. As well as an excess of dopamine in the limbic system and not an adequate amount in the cortex may produce a skeptical personality and potential paranoia. A shortage of Dopamine in the frontal lobe can diminish one’s memory. An increase of dopamine into the frontal lobe eases pain and heightens feelings of delight.
References
1. Gale, Emily, Li, Meng. "Midbrain dopaminergic neuron fate specification: Of mice and embryonic stem cells." Molecular Brain
1(2008) <http://www.molecularbrain.com
2. Int J Biochem Cell Biol. 2005 May;37(5):942-6. Epub 2004 Dec 2.
3. Seamans, J. Scholarpedia 2(2007) <http://www.scholarpedia.org/article/Dopamine_anatomy
4. Sprague, J., L. Bayraktaroglu, D. Clements, T. Conlin, D. Fashena, K. Frazer, M. Haendel, D. Howe, P. Mani, S. Ramachandran, K.
Schaper, E. Segerdell, P. Song, B. Sprunger, S. Taylor, C. Van Slyke and M. Westerfield. (2006) The Zebrafish Information Network: the zebrafish model organism database. Nucl. Acids Res. 34, D581-D585.
Additional information
http://neuronbank.org/wiki/images/f/f8/Dopamine_1.jpg
http://neuronbank.org/wiki/images/6/6d/Dopamine2.jpg
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