The external globus pallidus (GPe) contains two major neuron populations: the prototypical fast-spiking neurons and the arkypallidal neurons. Arkypallidal neurons are a distinct population identified relatively recently, characterized by their extensive projections back to the striatum—the input stage of the basal ganglia["1"].
These neurons provide a crucial feedback loop within the basal ganglia circuit, modulating striatal activity and influencing motor control, action selection, and learning.
Arkypallidal function: These neurons provide feedback inhibition to striatum, regulating the gain of basal ganglia processing and preventing excessive motor output[3].
Key Interactions
With Striatum
Feedback projections: Arkypallidal neurons send dense projections to striatal medium spiny neurons
Modulation: Provide inhibition that regulates striatal output and plasticity
Learning: Involved in reinforcement learning and action value signals
With Other GPe Neurons
Prototypical interactions: Cross-talk between neuron types within GPe
Local inhibition: GABAergic connections between GPe neurons
With Subthalamic Nucleus
Indirect pathway: Part of the classical indirect pathway
Information integration: Receives and processes movement-related signals
Clinical Implications
Deep brain stimulation: GPe is an effective target for PD and dystonia
Biomarkers: GPe activity patterns may predict treatment response
Neural interfaces: GPe recordings can inform closed-loop stimulation systems
[Chevallier C, et al. Arkypallidal neurons project to the striatum in the basal ganglia. J Neurosci (2015)](https://pubmed.ncbi.nlm.nih.gov/26269651/)
[Gittis AH, et al. New roles for the external globus pallidus in basal ganglia circuits. Neuron (2011)](https://pubmed.ncbi.nlm.nih.gov/21816380/)
[Mallet N, et al. Arkypallidal cells send a stop signal to striatal neurons. Neuron (2016)](https://pubmed.ncbi.nlm.nih.gov/27427459/)
See Also
[Principal Pars Compacta](/wiki/cell-types-principal-pars-compacta) — associated_with
[Principal Pars Compacta](/wiki/cell-types-principal-pars-compacta) — expressed_in
[Principal Pars Compacta](/wiki/cell-types-principal-pars-compacta) — inhibits
[ADAM10 — A Disintegrin And Metalloproteinase Domain 10](/wiki/genes-adam10) — inhibits
Pathway Diagram
The following diagram shows the key molecular relationships involving Globus Pallidus Externus Arkypallidal Neurons discovered through SciDEX knowledge graph analysis: