Decreased EAAT2 protein expression in the essential tremor cerebellar cortex

Area of Science:

• Neuroscience
• Genetics
• Pathology

Background:

• Essential tremor (ET) is a neurological disorder.
• Genetic links exist between ET and the Solute carrier family 1 (glial high affinity glutamate transporter), member 2 (SLC1A2) gene.
• SLC1A2 encodes excitatory amino acid transporter type 2 (EAAT2), crucial for clearing glutamate from synapses.

Purpose of the Study:

• To investigate the expression levels of glutamate transporters EAAT1 and EAAT2 in the cerebellar cortex of ET patients.
• To explore the potential role of glutamate transporter dysfunction in ET pathogenesis.

Main Methods:

• Western blotting was used to quantify EAAT1 and EAAT2 protein levels in postmortem cerebellar tissue from ET cases and controls.
• Immunohistochemistry was employed to study the cellular localization of EAAT1 and EAAT2.

Main Results:

• EAAT1 protein levels were comparable between ET cases and controls.
• EAAT2 protein levels were significantly reduced (approximately one-third) in the cerebellar cortex of ET cases compared to controls.
• EAAT2 was localized in astrocytic processes near Purkinje cells, a region implicated in ET pathology.

Conclusions:

• A significant reduction in cerebellar EAAT2 protein levels is observed in essential tremor.
• This deficit in EAAT2 may increase the susceptibility of Purkinje cells to excitotoxic damage in ET.