Age-specific onset of beta-amyloid in beagle brains.
As part of an effort to characterize Alzheimer's disease-like neuropathy in the canine brain we have determined the age of onset of spontaneous beta-amyloid deposition in 103 laboratory-raised beagles. Tissue samples for each subject were obtained from hippocampal and cortical regions and examined for the incidence and density of beta-amyloid deposition after staining with modified Bielschowsky silver stain and immunohistochemistry. Amyloid deposition was characterized as diffuse plaque or cloud-like formation. The diffuse type of beta-amyloid plaque formation predominated in all brain regions examined. A threshold effect of plaque development was observed; no plaques were apparent in dogs before the age of 10 years, while 36% of dogs aged 11.1-12.9, 60% of dogs aged 13.0-15.0, and 73% of dogs aged 15.1-17.8 developed beta-amyloid deposits. Additionally, a significant increase in plaque density was observed with increasing age.
Russell
M J
MJ
Department of Anesthesiology, University of California, Davis 95616, USA.
Bobik
M
M
White
R G
RG
Hou
Y
Y
Benjamin
S A
SA
Geddes
J W
JW
D017668:Age of Onset; D000375:Aging / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000473:pathology*; D001923:Brain Chemistry / Q000502:physiology; D016657:Cerebral Amyloid Angiopathy / Q000378:metabolism / Q000473:pathology*; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology; D004285:Dogs; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry
D016229:Amyloid beta-Peptides