Basal Ganglia · SNr · substructure
Substantia Nigra Pars Reticulata
Substantia nigra pars reticulata
One of the two output nuclei of the basal ganglia, together with the GPi: GABAergic neurons that brake the thalamus and superior colliculus.
Anatomy
- The ventral part of the SN; loosely arranged GABAergic neurons next to the cerebral peduncle.
- Receives input from the striatum (direct pathway) and the subthalamic nucleus.
Functions
- Tonic inhibition of the thalamus (VA/VL, mediodorsal) and superior colliculus; the inhibition is lifted for the wanted movement or saccade.
- Described in animal models as a gate controlling the spread of seizures.
Clinical
- Imbalance in basal ganglia output contributes to movement disorders such as dystonia and chorea.
In the model
How this structure is defined in the 3D model, and the data source.
CIT168 SNr probability map (right/left); volume equal to the CIT168 hard label.
References
This substructure’s card draws on the parent structure’s references: Substantia Nigra.
This page is for education; it must not be used on its own for diagnosis or treatment decisions.
Last reviewed by the author: 12 October 2026
3D model: built from the MNI ICBM152 average brain and the CerebrA, HCP-MMP1.0, CIT168, Harvard AAN, SUIT and Najdenovska thalamus atlases. License details in the atlas.