nigrostrialny

The nigrostriatal pathway, known in Polish as the droga nigrostrialna and described by the adjective nigrostrialny, is a dopaminergic projection from the substantia nigra pars compacta to the dorsal striatum (primarily the caudate nucleus and putamen). It travels as part of the basal ganglia circuitry that coordinates movement.

Functionally, the pathway modulates motor control by regulating the activity of the direct and indirect pathways within the striatum. Dopamine acts on D1 and D2 receptor-expressing neurons to influence thalamocortical signaling, thereby affecting movement initiation, scaling, and procedural learning. The nigrostriatal system is more associated with planning and execution of voluntary movements and habit formation rather than reward processing, which is more closely linked to other dopaminergic systems.

Clinical significance is most prominently illustrated by Parkinson’s disease, in which degeneration of nigrostriatal dopaminergic neurons leads to reduced dopaminergic input to the dorsal striatum. This results in bradykinesia, resting tremor, rigidity, and postural instability. Treatments aim to restore dopaminergic activity in this pathway, including L-DOPA, dopamine receptor agonists, and MAO-B inhibitors; deep brain stimulation may be used in advanced cases to modulate downstream circuits.

Anatomically, the nigrostriatal tract originates in the substantia nigra pars compacta and projects to the dorsal striatum, with fibers passing via pathways that include the medial forebrain bundle. The integrity of this pathway is a key factor in normal motor function and is a central focus in movement disorder research and therapy.