Selective white matter pathology induces a specific impairment in spatial working memory.

Area of Science:

• Neuroscience
• Aging Research
• Cognitive Science

Background:

• White matter integrity is crucial for cognitive function and neuronal communication.
• Age-related cognitive decline is linked to white matter damage.
• Animal models are needed to study white matter pathology in aging, but require parallel behavior and pathology assessment.

Purpose of the Study:

• To investigate the effects of chronic hypoperfusion-induced white matter damage on spatial memory in mice.
• To establish a model for studying white matter pathology in aging.
• To determine if white matter damage, in the absence of gray matter damage, selectively impairs cognitive function.

Main Methods:

• Induce diffuse white matter damage via chronic hypoperfusion (bilateral carotid stenosis) in C57Bl/6J mice.
• Assess spatial memory using water maze and 8-arm radial arm maze.
• Systematically evaluate white matter integrity (myelin, axon, glia) and neuronal damage using immunohistochemistry and histology.

Main Results:

• Diffuse white matter damage was successfully induced in hypoperfused mice across three cohorts.
• No significant gray matter damage (neuronal perikarya) was observed in the studied hypoperfused mice after exclusion criteria were applied.
• Hypoperfused mice with white matter damage exhibited selective impairment in spatial working memory, while other spatial memory measures remained intact.

Conclusions:

• Diffuse white matter pathology, independent of gray matter damage, selectively impairs spatial working memory.
• This study provides a valuable animal model for investigating the mechanisms of white matter aging.
• Parallel assessment of behavior and neuropathology in the same animal is critical for understanding cognitive decline.