Selective Loss of Thin Spines in Area 7a of the Primate Intraparietal Sulcus Predicts Age-Related Working Memory Impairment
| Autor: | Sarah E. Motley, Mark G. Baxter, John H. Morrison, Yael S. Grossman, Peter R. Rapp, William G.M. Janssen, Dani Dumitriu |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Male Aging Dendritic spine Dendritic Spines Posterior parietal cortex Intraparietal sulcus 03 medical and health sciences Random Allocation 0302 clinical medicine biology.animal Parietal Lobe Animals Primate Prefrontal cortex Research Articles Memory Disorders biology Cell Death Working memory General Neuroscience Macaca mulatta 030104 developmental biology Memory Short-Term Female sense organs Neuron death Neuroscience 030217 neurology & neurosurgery Brodmann area Forecasting |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 38(49) |
| ISSN: | 1529-2401 |
| Popis: | Brodmann area 7a of the parietal cortex is active during working memory tasks in humans and nonhuman primates, but the composition and density of dendritic spines in area 7a and their relevance both to working memory and cognitive aging remain unexplored. Aged monkeys have impaired working memory, and we have previously shown that this age-induced cognitive impairment is partially mediated by a loss of thin spines in prefrontal cortex area 46, a critical area for working memory. Because area 46 is reciprocally connected with area 7a of the parietal cortex and 7a mediates visual attention integration, we hypothesized that thin spine density in area 7a would correlate with working memory performance as well. To investigate the synaptic profile of area 7a and its relevance to working memory and cognitive aging, we investigated differences in spine type and density in layer III pyramidal cells of area 7a in young and aged, male and female rhesus macaques (Macaca mulatta) that were cognitively assessed using the delayed response test of working memory. Area 7a shows age-related loss of thin spines, and thin spine density positively correlates with delayed response performance in aged monkeys. In contrast, these cells show no age-related changes in dendritic length or branching. These changes mirror age-related changes in area 46 but are distinct from other neocortical regions, such as V1. These findings support our hypothesis that cognitive aging is driven primarily by synaptic changes, and more specifically by changes in thin spines, in key association areas.SIGNIFICANCE STATEMENTThis study advances our understanding of cognitive aging by demonstrating the relevance of area 7a thin spines to working memory performance. This study is the first to look at cognitive aging in the intraparietal sulcus, and also the first to report spine or dendritic measures for area 7a in either young adult or aged nonhuman primates. These results contribute to the hypothesis that thin spines support working memory performance and confirm our prior observation that cognitive aging is driven by synaptic changes rather than changes in dendritic morphology or neuron death. Importantly, these data show that age-related working memory changes are not limited to disruptions of the prefrontal cortex but also include an association region heavily interconnected with prefrontal cortex. |
| Databáze: | OpenAIRE |
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