Basal Ganglia · GPe · substructure
Globus Pallidus, External Segment
Globus pallidus externus
The relay station of the indirect pathway: tunes the suppression of unwanted movements by braking the subthalamic nucleus.
Anatomy
- The outer part of the lentiform nucleus next to the putamen; separated from the GPi by the medial medullary lamina.
- Receives GABAergic input from the striatum (indirect pathway, enkephalinergic neurons); reciprocally connected with the subthalamic nucleus.
Functions
- Indirect pathway: striatum → GPe → subthalamic nucleus → GPi/SNr.
- The GPe–STN loop regulates basal ganglia rhythms (beta oscillations).
Clinical
- Excess beta rhythm in the GPe–STN loop is seen in Parkinson’s disease.
In the model
How this structure is defined in the 3D model, and the data source.
CIT168 GPe probability map (right/left). The outer shell is the CerebrA pallidum label; the borders of the two atlases may differ slightly.
References
This substructure’s card draws on the parent structure’s references: Globus Pallidus.
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.