Neuronal damage and decrease of central acetylcholine level following permanent occlusion of bilateral common carotid...

Area of Science:

• Neuroscience
• Cerebrovascular Research
• Neurochemistry

Background:

• Chronic cerebral hypoperfusion is a significant factor in cognitive decline.
• Understanding the mechanisms of neuronal damage and neurotransmitter changes is crucial for developing therapeutic strategies.

Purpose of the Study:

• To investigate neuronal damage and changes in acetylcholine (ACh) and choline (Ch) levels following permanent bilateral common carotid artery occlusion (2VO) in rats.
• To differentiate between acute ischemic damage and progressive neurodegeneration.
• To correlate neurochemical alterations with observed neuronal changes.

Main Methods:

• Induction of permanent 2VO in rats.
• Histopathological examination of brain tissues (cerebral cortex, striatum, hippocampus, white matter) at 1 and 4 months post-operation.
• Measurement of central ACh and Ch content in various brain regions using biochemical assays.

Main Results:

• Two types of neuronal damage were identified: acute infarctions in the cortex/striatum and progressive damage (neuronal loss in hippocampus, white matter rarefaction) evident at 4 months.
• Significant decrease in striatal ACh at 1 month, and widespread decreases in ACh and Ch levels in multiple brain regions by 4 months.
• Neurotransmitter changes occurred without accompanying necrosis, suggesting non-infarct related mechanisms.

Conclusions:

• Permanent 2VO induces both acute ischemic damage and progressive neurodegeneration.
• Chronic cerebral hypoperfusion leads to significant cholinergic dysfunction.
• These neurodegenerative and neurochemical changes are implicated in the development of long-lasting cognitive deficits observed in rats.