Nigrostriatal system

The nigrostriatal pathway or the nigrostriatal bundle (NSB), is a dopaminergic pathway that connects the substantia nigra pars compacta (SNc) with the dorsal striatum (i.e., the caudate nucleus and putamen). 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. Dopaminergic neurons of this pathway synapse onto GABAergic neurons.

Loss of dopamine neurons in the SNc is one of the main pathological features of Parkinson's disease, leading to a marked reduction in dopamine function in this pathway. Depletion of neurons in this pathway lead to the symptomatic motor deficits of Parkinson's disease including tremors, rigidity, and postural imbalance.

The following are considered part of the nigrostriatal pathway.

The substantia nigra is located in the midbrain. It has two distinct parts, the pars compacta and the pars reticulata. The pars compacta is part of the nigrostriatal pathway and relays information to the basal ganglia by supplying dopamine to the striatum. The pars reticulata in conjunction with the globus pallidus in the basal ganglia allows for inhibition of the thalamus.

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