Dopaminergic pathways

Mesolimbic dopaminergic and serotonergic pathways.

Dopaminergic pathways are neural pathways in the brain which transmit the neurotransmitter dopamine from one region of the brain to another.^[1]

The neurons of the dopaminergic pathways have axons which run the entire length of the pathway. The neurons' soma produces the enzymes that synthesize dopamine, and they are then transmitted via the projecting axons to their synaptic destinations, where most of the dopamine is produced. Dopaminergic nerve cell bodies in such areas as the substantia nigra tend to be pigmented due to the presence of the black pigment melanin.

Examples

There are eight dopaminergic pathways, but the four major ones are:

Name	Description	Disorders
mesolimbic pathway	The mesolimbic pathway transmits dopamine from the ventral tegmental area (VTA) to the nucleus accumbens. The VTA is located in the midbrain, and the nucleus accumbens is in the limbic system. The "meso-" prefix in the word "mesolimbic" refers to the midbrain, or "middle brain", since "meso" means "middle" in Greek.	schizophrenia
mesocortical pathway	The mesocortical pathway transmits dopamine from the VTA to the frontal cortex. The "meso-" prefix in "mesocortical" refers to the VTA which is located in the midbrain, and "cortical" refers to the cortex.	schizophrenia
nigrostriatal pathway	The nigrostriatal pathway transmits dopamine from the substantia nigra to the striatum. This pathway is associated with motor control.	Parkinson's disease, chorea
tuberoinfundibular pathway	The tuberoinfundibular pathway transmits dopamine from the hypothalamus to the pituitary gland. This pathway influences the secretion of certain hormones, including prolactin. "Infundibular" in the word "tuberoinfundibular" refers to the infundibulum out of which the pituitary gland develops.	hyperprolactinaemia

Minor ones include the incertohypothalamic pathway within the hypothalamus, which has a role in sexual behaviour.

References

1. ^ "Beyond the Reward Pathway". http://learn.genetics.utah.edu/content/addiction/reward/pathways.html. Retrieved 2009-10-23. 

• The Reward Circuit. Part of "The Brain From Top To Bottom". The content of this page is copylefted and has been used in this article.