The brains of three marmosets (Callithrix jacchus) injected intracerebrally 6-7 years earlier with brain tissue from a patient with early onset
Alzheimer's disease were found to contain moderate numbers of
amyloid plaques with associated argyrophilic dystrophic neurites and
cerebral amyloid angiopathy but no neurofibrillary tangles. The plaques and vascular
amyloid stained positively with
antibodies to beta (A4)-protein. The brains of three age-matched control marmosets from the same colony did not show these neuropathological features. The brain of one of two marmosets injected with brain tissue from a patient with
prion disease with concomitant
beta-amyloid plaques and
cerebral amyloid angiopathy also showed
beta-amyloid plaques and angiopathy but no spongiform
encephalopathy. An occasional plaque was found in the brains of two of four marmosets injected with brain tissue from three elderly patients with age-related pathology, two of whom had an additional diagnosis of possible
prion disease. Neither plaques nor
cerebral amyloid angiopathy were found in six other marmosets who were older than the injected animals, in 12 further marmosets who were slightly younger but who had been injected several years previously with brain tissue which did not contain
beta-amyloid, or in 10 younger marmosets who had been subjected to various
neurosurgical procedures. These results suggest that cerebral beta-
amyloidosis may be induced by the introduction of exogenous
amyloid beta-protein.