Reduced Bergmann glial process terminations and lateral appendages in essential tremor

Area of Science:

• Neuroscience
• Cell Biology
• Pathology

Background:

• Essential tremor (ET) pathology primarily involves the cerebellum, with known changes in Purkinje cells and neuronal connections.
• Bergmann glia, crucial astrocytes in the cerebellar cortex, ensheath Purkinje cell synapses and offer neuroprotection.
• The specific morphology of Bergmann glia and its potential alteration in ET remains uninvestigated.

Purpose of the Study:

• To investigate alterations in Bergmann glia morphology in the postmortem cerebellum of individuals with essential tremor.
• To determine if structural changes in Bergmann glia contribute to the pathophysiology of essential tremor.

Main Methods:

• Utilized the Golgi-Kopsch method for visualizing Bergmann glia in postmortem cerebellar tissue.
• Employed computerized three-dimensional cell reconstruction for detailed morphological analysis.
• Quantified terminal structures (terminations, lateral appendage density) and radial processes (length, branch order, volume) in 34 ET cases and 17 controls.

Main Results:

• Bergmann glia in ET cases showed a significant decrease in process terminations (31.9%) and lateral appendage density (35.7%).
• No significant differences were observed in total process length or branch length between ET cases and controls.
• A reduction in the number of secondary and tertiary branches, as well as tertiary branch volume, was noted in ET cases.

Conclusions:

• Bergmann glia in essential tremor exhibit significant alterations, particularly in their terminal structures.
• The radial processes of Bergmann glia appear relatively preserved in essential tremor.
• These findings suggest a potential role for Bergmann glia, specifically their synaptic interactions, in the underlying pathophysiology of essential tremor.