Age-related spatial cognitive impairment is correlated with a decrease in ChAT in the cerebral cortex, hippocampus...

Area of Science:

• Neuroscience
• Aging Research
• Cognitive Disorders

Background:

• Mechanisms of cognitive disorders in aging are not fully understood.
• Senescence-accelerated mice (SAM) P8 model exhibits aging phenotypes.
• SAM resistant/1 (R1) mice serve as a control for normal aging.

Purpose of the Study:

• To investigate the expression of choline acetyltransferase (ChAT) in the brain of SAM P8 mice.
• To correlate ChAT levels with age-related cognitive decline in the P8 model.

Main Methods:

• Behavioral testing using the Morris water maze (MWM) to assess learning and memory.
• Quantification of ChAT protein and mRNA levels via immunostaining, Western blotting, and quantitative PCR (QPCR).
• Analysis of cerebral cortex, hippocampus, and forebrain tissues in P8 and R1 mice at different ages (4, 8, 12 months).

Main Results:

• P8 mice aged 8 and 12 months demonstrated significant age-related cognitive impairment in the MWM compared to 4-month-old P8 and R1 mice.
• A significant decrease in both ChAT protein and mRNA levels was observed in older P8 mice (8 and 12 months) across brain regions.
• Pearson correlation revealed a positive correlation between MWM performance (latency) and ChAT levels in P8 mice, a correlation absent in R1 mice.

Conclusions:

• Reduced choline acetyltransferase (ChAT) expression is a key factor contributing to age-related learning and memory impairments in the SAM P8 model.
• The SAM P8 mouse strain is a valuable tool for studying the molecular basis of cognitive aging and associated disorders.