The 'mesolimbic pathway' is one of the
neural pathways in the
brain that links the
ventral tegmentum in the
midbrain to the
nucleus accumbens, which is located in the
striatum and is a part of the
limbic system. It is one of the four major pathways where the
neurotransmitter dopamine is found.
Function
The mesolimbic pathway is thought to be involved in producing
pleasurable feeling, and is often associated with feelings of
reward and
desire, particularly because of the connection to the
nucleus accumbens, which is also associated with these states. Because of this, this pathway is heavily implicated in
neurobiological theories of
addiction. However, recent research has pointed towards this pathway being involved in
incentive salience rather than euphoric mood states.
Clinical significance
The mesolimbic pathway is one of the major pathways targeted by
antipsychotic medication. Although the process is not fully understood, it has been found that disruption of dopamine function (particularly, an excess of dopamine) in this area has been linked to
psychosis and the 'positive symptoms' of
schizophrenia (particularly
delusions and
hallucinations). Successful antipsychotic medication is therefore thought to have its effect by blocking
dopamine receptors in this pathway.
Dopamine
neurons are lost in the mesolimbic pathway in
Parkinson's Disease; however, they are lost far more quickly in the
nigrostriatal pathway, and, because deficits do not become apparent until a reduction of 80-90% in the numbers of neurons, their loss here is asymptomatic.
Other pathways
Other major dopamine pathways include:
★
mesocortical pathway
★
nigrostriatal pathway
★
tuberoinfundibular pathway
See also
★
antipsychotic
★
tardive dysphrenia
External links
★
Diagram at utah.edu