Preservation of hippocampal neuron numbers in aged rhesus monkeys

Abstract

Preservation of hippocampal neuron numbers in aged rhesus monkeys Keuker, J.I.H.; Luiten, P.G.M.; Fuchs, E. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. AbstractTo investigate whether or not aging of nonhuman primates is accompanied by a region-specific neuron loss in the hippocampal formation, we used the optical fractionator technique to obtain stereological estimates of unilateral neuron numbers of the hippocampi of eight young (0-4 years) and five aged (18-31 years) male rhesus monkeys (Macaca mulatta). Our results show a preservation of neurons (mean × 10 3 ± S.D. × 10 3 ) in the subiculum (young = 588 ± 124, aged = 612 ± 207), CA1 (young = 1051 ± 249, aged = 1318 ± 311), CA2 (young = 100 ± 18, aged = 113 ± 12), CA3 (young = 478 ± 125, aged = 509 ± 139), hilus (young = 337 ± 115, aged = 394 ± 90), and dentate gyrus (young = 5550 ± 1725, aged = 7799 ± 2087) of the hippocampal formation. These results confirm a previous stereological study in rhesus monkeys, but are in conflict with data for humans, showing age-dependent region-specific alterations in the hippocampal formation.

A morphologically distinct granule cell type in the dentate gyrus of the red fox correlates with adult hippocampal neurogenesis

“…Interestingly, the average of 11.3 million granule cells in foxes is similar to what has been found in rhesus monkeys (Keuker et al, 2003), pigs (Holm and West, 1994) and in some human data (Korbo et al, 2004), despite its' much smaller overall brain size. On the other hand, the number of large granule cells correlates with neurogenesis but not with total granule cell number.…”

“…calculated from BrdU positive cells after one injection and three week of survival time (Kozorovitskiy et al, 2005;Leuner et al, 2007) or ~0.02% in Rhesus monkeys (Macaca mulatta, after one to five BrdU injections and variable survival times (Gould et al, 1999;Keuker et al, 2003). Although the primate data has been derived using another marker, this difference alone is unlikely to explain the at least 10-fold differences in the normalized proliferation rates when compared to rodents.…”

Regional protein levels of cytosolic phospholipase A2 and cyclooxygenase-2 in Rhesus monkey brain as a function of age

“…Indeed, recent reports using modern stereological cell-counting methods did not show any significant agerelated loss of hippocampal neurons in rats [44], mice [13], monkeys [30,41], or humans [51]. Peters and Sethares reported that even with significant thinning with age of cortical layer 1, accompanied by a loss of some dendrites and spines and a decrease in the frequency of synapses, in the occipital and prefrontal cortex in Rhesus monkeys, there was no significant age-related changes in the number of neurons, astrocytes, or microglia and oligodendrocytes in the layer [42].…”

Neuronal and morphological bases of cognitive decline in aged rhesus monkeys

“…When unbiased stereological methods are applied, there are no age-dependent differences in neuronal number or density in the subiculum, CA1, CA2, CA3, DG, and EC in rhesus monkeys Amaral 1993;Rapp 1995;Peters et al 1996;Gazzaley et al 1997;Merrill et al 2000;Keuker et al 2003). Although based on a small number of monkeys, there is no evidence for a relationship between DNMS scores and neuronal numbers in these regions Rapp 1995).…”