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Chronic Post-Ischemia Pain Model for Complex Regional Pain Syndrome Type-I in Rats
Published on: January 21, 2020
Zona incerta: a role in central pain
Radi Masri1, Raimi L Quiton, Jessica M Lucas
1Department of Anatomy, University of Maryland School of Medicine, 20 Penn St., Baltimore, MD 21201, USA.
Journal of Neurophysiology
|May 1, 2009
Summary
Central pain syndrome (CPS) involves dysfunction in the central nervous system (CNS). This study reveals suppressed inhibitory signals from the zona incerta (ZI) to the posterior thalamus (PO) contribute to CPS development.
Area of Science:
- Neuroscience
- Pain Research
- Central Nervous System Disorders
Background:
- Central pain syndrome (CPS) is a prevalent neurological condition arising from CNS lesions or dysfunction.
- The underlying pathophysiology of CPS remains poorly understood despite its long-recognized existence.
- Recent work highlighted inhibitory regulation of the posterior thalamus (PO) by the zona incerta (ZI).
Purpose of the Study:
- To investigate the hypothesis that CPS is linked to aberrant inhibitory control of the PO by the ZI.
- To elucidate the role of ZI-PO pathway dysfunction in the development of central pain.
Main Methods:
- Electrophysiological recordings of single units in the ZI and PO of animal models with CPS induced by spinal cord lesions.
- Comparison of neuronal activity between lesioned animals and sham-operated controls.
- Assessment of afferent drive from the spinal trigeminal nucleus and activity in the ventroposterior thalamus.
Main Results:
- ZI neurons in lesioned animals showed reduced spontaneous firing rates and somatosensory evoked responses compared to controls.
- PO neurons in lesioned rats exhibited increased spontaneous firing rates and heightened responses to noxious and innocuous stimuli.
- No significant changes were observed in afferent drive from the spinal trigeminal nucleus or ventroposterior thalamus activity.
Conclusions:
- Central pain syndrome can arise from diminished inhibitory input from the zona incerta to the posterior thalamus.
- This ZI-PO pathway dysfunction represents a key mechanism contributing to the pathophysiology of CPS.
- Targeting the ZI-PO pathway may offer novel therapeutic strategies for managing central pain.
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