Neuropathologic changes in the gerbil brain after chronic hypoperfusion

Abstract

Background and purpose: An animal model has been developed to elucidate the pathological changes in brain cytoskeletal proteins during chronic hypoperfusion.

Methods: Newly designed coiled clips were placed around both carotid arteries of Mongolian gerbils (n = 10) to cause stenosis without occlusion. Those gerbils showing impaired learning ability by the passive avoidance paradigm were killed for neuropathologic study after 12 weeks.

Results: The brains showed ventricular dilatation, cortical atrophy, and rarefaction of the white matter. Immunoreactivity to anti-microtubule-associated protein 2 antibody in the cerebral cortex and the hippocampus was diminished, indicating dendritic changes of neurons. In the thalamic axonal regions, staining with anti-neurofilament 200K protein antibody was increased, suggesting increased amounts of neurofilament proteins or increased phosphorylation of the protein. Increased immunoreactivity to anti-glial fibrillary acidic protein antibody was observed in a wedge-shaped configuration, corresponding to the border zone of perfusion by small vessels.

Conclusions: These findings suggest that changes in the cytoskeletal proteins in dendrites, axons, and glial cells may cause neuronal death under conditions of chronic cerebral hypoperfusion.