AD in Animals?
sd_chin at POSTOFFICE.UTAS.EDU.AU
Fri May 26 00:24:48 EST 1995
The expression AD in animals may not be correct because non of the
transgenic strains or the old animals studied show any symptoms of AD,
only some of the neuropathology. Cork et al reported the occurance of
amyloid deposits in aged brown bears and in an aged polar bear. Numerous
areticles have been published on amyloid deposition in old sheep and dogs,
but does not mean that these animals develop AD as we know (or rather,
diagnose) it. The criteria for diagnosis in humans include cognitive and
metal state tests and observation of behaviour and personal grooming
assessment. As it is, this seems rather arbitrary.
Anyway, attempts have been made to produce transgenic mice to give a
clearer picture of the neuropathology and its implications. This cognitive
impairement that results cannot be correctly assessed in these animals.
Coria, et al (1992) Neuropath. Applied Neurobiol. 18. 27-35 reports the
occurance of Amyloid precursor protein in normal rat nervous system.
An article in Nature of 9/2/95 reports plaque formation in a transgenic
mouse strain which expresses excess amounts of human amyloid precursor
protein. However, this model is not fool proof. The flaw is that there
hasn't been any neurofibrillary tangles in these mice. Therefore, whether
they reflect AD pathology or not is debatable. They may be appropriate to
study certain aspects of the disease (senile plaques, amyloid angiopathy
and neuritic changes due to amyloid).
Devika Chin Grasby
Dept of Physiology
Flinders Medical Centre
Phone: (08) 204 4107
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