SPID#: 47 In order to determine whether there are age-related changes in the supragranular layer of the dentate gyrus of the rhesus monkey, we examined this layer in monkeys 4 to 35 years of age, spanning the entire range of adulthood of this species. Electron microscopic analyses of this region were conducted to determine whether there is an age-related change in the number of synapsing axon terminals, in the cross-sectional area of these terminals, or in the length of the postsynaptic density at the synaptic junction. In a subset of our monkeys (n = 6, ages 4 to 31 years), we compared three different approaches to the estimation of synaptic density (1) the conventional method, in which synapse numbers are expressed per unit area of the examined tissue section; (2) the empirical formula of Colonnier and Beaulieu for converting areal densities into number of synapses per unit volume; and (3) the disector method, a stereological approach to the estimation of number of synapses per unit volume that makes no assumption about the shape of the objects. The three methods were highly intercorrelated (r's = .89), and none of the methods revealed an age-related loss of synapses. In addition, the conventional method showed no age-related change in the number of axodendritic or axospinous synapses, the size of cross-sectional area of the synapsing terminals, or the length of the postsynaptic densities of synapses. Thus, since the synapses in the supragranular layer of the dentate gyrus do not change, one has to look somewhere else for structural changes that could be considered responsible for age-related cognitive decline and memory loss. Tissues of all monkeys were shared with other projects.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
Primate Research Center Grants (P51)
Project #
Application #
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Beck, Goichi; Maehara, Shunsuke; Chang, Phat Ly et al. (2018) A Selective Phosphodiesterase 10A Inhibitor Reduces L-Dopa-Induced Dyskinesias in Parkinsonian Monkeys. Mov Disord 33:805-814
Georgieva, Maria; Sia, Jonathan Kevin; Bizzell, Erica et al. (2018) Mycobacterium tuberculosis GroEL2 Modulates Dendritic Cell Responses. Infect Immun 86:
Tedesco, Dana; Grakoui, Arash (2018) Environmental peer pressure: CD4+ T cell help in tolerance and transplantation. Liver Transpl 24:89-97
Mavigner, Maud; Habib, Jakob; Deleage, Claire et al. (2018) Simian Immunodeficiency Virus Persistence in Cellular and Anatomic Reservoirs in Antiretroviral Therapy-Suppressed Infant Rhesus Macaques. J Virol 92:
Walker, Lary C (2018) Prion-like mechanisms in Alzheimer disease. Handb Clin Neurol 153:303-319
Kamberov, Yana G; Guhan, Samantha M; DeMarchis, Alessandra et al. (2018) Comparative evidence for the independent evolution of hair and sweat gland traits in primates. J Hum Evol 125:99-105
Wakeford, Alison G P; Morin, Elyse L; Bramlett, Sara N et al. (2018) A review of nonhuman primate models of early life stress and adolescent drug abuse. Neurobiol Stress 9:188-198
Singh, Arun; Jenkins, Meagan A; Burke Jr, Kenneth J et al. (2018) Glutamatergic Tuning of Hyperactive Striatal Projection Neurons Controls the Motor Response to Dopamine Replacement in Parkinsonian Primates. Cell Rep 22:941-952
Maddox, S A; Kilaru, V; Shin, J et al. (2018) Estrogen-dependent association of HDAC4 with fear in female mice and women with PTSD. Mol Psychiatry 23:658-665
Li, Chun-Xia; Kempf, Doty J; Tong, Frank C et al. (2018) Longitudinal MRI Evaluation of Ischemic Stroke in the Basal Ganglia of a Rhesus Macaque (Macaca mulatta) with Seizures. Comp Med :

Showing the most recent 10 out of 912 publications