SARS-CoV-2 Morbidity in the CNS and the Aged Brain Specific Vulnerability

Area of Science:

• Neuroscience
• Immunology
• Virology

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19, affecting multiple organs including the brain.
• Neurological symptoms like stroke and encephalitis are more severe in elderly COVID-19 patients.
• The aged brain's vulnerability may stem from impaired immunity and altered homeostatic mechanisms.

Purpose of the Study:

• To investigate the heightened susceptibility of the aged brain to SARS-CoV-2 infection.
• To explore the role of glial cells in age-related brain damage during COVID-19.

Main Methods:

• Review of existing literature on SARS-CoV-2, aging, and neuroinflammation.
• Analysis of age-associated changes in neuronal and glial cells.
• Hypothesizing the impact of glial cell phenotype on viral brain damage.

Main Results:

• Elderly individuals exhibit impaired immune defenses and altered brain homeostasis.
• Specific age-related changes in glia include dystrophic forms, reduced waste clearance, and activated microglia/astrocytes.
• Neuronal changes may indirectly contribute, while glial alterations play a more direct role in SARS-CoV-2 brain pathology.

Conclusions:

• The frail glial cell phenotype in the elderly is a plausible reason for severe brain damage following SARS-CoV-2 infection.
• Targeting glial cell function may be a therapeutic strategy for mitigating COVID-19 neurological complications in older adults.