Learn More
The rhesus monkey offers a useful model of normal human aging because when monkeys are tested on a battery of behavioral tasks that can also be used to evaluate cognition in humans, it is found that the monkeys undergo an age-related decline in several domains of cognitive function as do humans. In monkeys these changes begin at about 20 years of age. To(More)
The retrogradely transported horseradish peroxidase (HRP) method was used to study the areal and laminar distribution of neurons sending their axons to ipsilateral and contralateral visual cortical areas 17, 18, 19, and MT in the squirrel monkey. Further details regarding neuron type (stellate or pyramidal), size class, and spatial grouping of the cells(More)
Studies on human postmortem material report lower brain weights in older than in younger cohorts, whereas there is no apparent change with age in the rhesus monkey. In view of these contrasting results, we examined the pattern of brain weight across the life span in the chimpanzee, one of the closest biological relatives of humans. To place the study in(More)
The projections from area 18 and the lateral geniculate nucleus onto area 17 of the squirrel monkey (Saimiri) were investigated with retrograde (horseradish peroxidase) and anterograde (tritiated proline) labelling techniques, and the (Fink-Heimer) silver impregnation method for degenerating axons and their terminals. The association fibers from area 18(More)
The influence of anomalous visual experience on the postnatal regulation of axial eye elongation was explored by raising newborn rhesus monkeys under different types of monocular and binocular deprivation and comparing their eye growth pattern with that of age-matched normal monkeys. Monocular manipulations included eyelid suture to eliminate pattern(More)
Antibodies to muscarinic cholinergic receptor proteins m1 to m4 were used in striate cortex tissue of normal rhesus monkeys to determine the laminar distribution of these proteins with special attention to geniculorecipient layers. The normal patterns were compared to those of monkeys whose ocular dominance system had been altered by visual deprivation. In(More)
Radiofrequency lesions were made in the lateral geniculate nuclei of six squirrel monkeys. The resulting degenerating terminals and their postsynaptic structures in layer IV of area 17 were quantitatively categorized on photomontages covering large areas of neuropil. Two to five days after the lesion, numerous axon terminals were affected by a variety of(More)
Neuropathological findings in three aged chimpanzees were compared with those in rhesus monkeys and individuals with Alzheimer disease. Senile plaques and blood vessels were immunoreactive for amyloid beta-protein and apolipoprotein E (apoE) in the nonhuman primates, recapitulating findings in human aging and Alzheimer disease. Neurofibrillary tangles,(More)
Because aged nonhuman primates show beta-amyloid (A beta) deposition in senile plaques and blood vessels similar to that seen in human aging and AD, we used C-terminal specific antibodies to A beta40 and A beta42 to investigate A beta peptide length in the brains of 11 aged rhesus monkeys and a 59-year-old chimpanzee. In contrast to AD, where the earliest(More)
The distribution of terminal fields of retinocollicular fibers was studied in squirrel monkeys with the autoradiographic technique. The terminals were aggregated into patches which were separated by intervening gaps. The ipsilateral patches were particularly distinct. The patches as well as th gaps ranged in size from 50 to 200 microns. In the most(More)