The nigrostriatal pathway is a neural pathway that connects the substantia nigra with the striatum. It is one of the four major dopamine pathways in the brain, and is particularly involved in the production of movement, as part of a system called the basal ganglia motor loop.
Loss of dopamine neurons in the substantia nigra is one of the main pathological features of Parkinson's disease, leading to a marked reduction in dopamine function in this pathway. The symptoms of the disease typically do not show themselves until 80-90% of dopamine function has been lost.
This pathway is also implicated in producing tardive dyskinesia, one of the side-effects of antipsychotic drugs. These medications (particularly the older typical antipsychotics) block D2 dopamine receptors in multiple pathways in the brain.
The desired clinical effect of reducing psychotic symptoms is thought to be associated with blocking dopamine function in the mesolimbic pathway only. However, as many of these drugs are not selective, they block dopamine in all pathways. When this happens in the nigrostriatal pathway, similar movement problems to those found in Parkinson's disease can occur.
Other dopamine pathways
Other major dopamine pathways include:
- ^ Diaz, Jaime. How Drugs Influence Behavior. Englewood Cliffs: Prentice Hall, 1996.
Neurotransmitter systems Acetylcholine BA/MSerotonin pathwaysRaphe nuclei · Anterior raphespinal tract · Lateral raphespinal tract AA Brain and spinal cord: neural tracts and fasciculi Sensory/
ascending3°: → Posterior limb of internal capsule → Postcentral gyrusFast/lateralSlow/medial
descendingPyramidalMidbrain tectum → Tectospinal tract → muscles of neck
direct: 1° (Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 4° (Thalamocortical radiations → Supplementary motor area) → 5° (Motor cortex)
indirect: 1° (Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus → Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area) → 7° (Motor cortex)nigrostriatal pathway: Pars compacta → Striatum
CerebellarAfferentEfferentFastigial nucleus in Flocculonodular lobe/vestibulocerebellum → Vestibulocerebellar tract → Vestibular nucleusBidirectional:
Wikimedia Foundation. 2010.
Look at other dictionaries:
nigrostriatal — Referring to the efferent connection of the substantia nigra with the striatum. See substantia nigra. * * * ni·gro·stri·a·tal .nī grō strī āt əl adj of, relating to, or joining the corpus striatum and the substantia nigra <the nigrostriatal… … Medical dictionary
nigrostriatal — ¦nīgrō, ¦nig ˌ adjective Etymology: (substantia) nigra + o + striatal : of, relating to, or joining the corpus striatum and the substantia nigra the nigrostriatal dopamine pathway degenerates in Parkinson s disease S.H.Snyder et al … Useful english dictionary
Mesolimbic pathway — Mesolimbic dopaminergic and serotonergic pathways. The mesolimbic pathway is one of the dopaminergic pathways in the brain. The pathway begins in the ventral tegmental area of the midbrain and connects to the limbic system via the nucleus… … Wikipedia
Neural pathway — A neural pathway, neural tract, or neural face, connects one part of the nervous system with another and usually consists of bundles of elongated, myelin insulated neurons, known collectively as white matter. Neural pathways serve to connect… … Wikipedia
Mesocortical pathway — The mesocortical pathway is a neural pathway that connects the ventral tegmentum to the cerebral cortex, particularly the frontal lobes. It is one of the four major dopamine pathways in the brain. It is essential to the normal cognitive function… … Wikipedia
Posterior column-medial lemniscus pathway — Originating in peripheral sensory receptors, the posterior column medial lemniscus pathway transmits fine touch and conscious proprioceptive information to the brain. Latin via column … Wikipedia
Tuberoinfundibular pathway — The tuberoinfundibular pathway refers to a population of dopamine neurons in the arcuate nucleus of the mediobasal hypothalamus (the tuberal region ) that project to the median eminence (the infundibular region ). It is one of the four major… … Wikipedia
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. The neurons of the dopaminergic pathways hav … Wikipedia
Neurotransmitter — For an introduction to concepts and terminology used in this article, see Chemical synapse. Structure of a typical chemical synapse Postsynaptic density Voltage gated Ca++ c … Wikipedia
Substantia nigra — Brain: Substantia nigra Section through superior colliculus showing Substantia nigra … Wikipedia