Reduced Cognitive Performance in Aged Rats Correlates with Increased Excitation/Inhibition Ratio in the Dentate Gyrus in Response to Lateral Entorhinal Input
| Autor: | Ming Teng Koh, Michela Gallagher, Alfredo Kirkwood, Michelle C.D. Bridi, Trinh T. Tran |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Male Aging Optogenetics Biology Hippocampal formation Inhibitory postsynaptic potential Article Temporal lobe 03 medical and health sciences 0302 clinical medicine Organ Culture Techniques Postsynaptic potential Animals Entorhinal Cortex Cognitive Dysfunction Rats Long-Evans 10. No inequality General Neuroscience Dentate gyrus Excitatory Postsynaptic Potentials Entorhinal cortex Rats 030104 developmental biology Inhibitory Postsynaptic Potentials Dentate Gyrus Excitatory postsynaptic potential Neurology (clinical) Geriatrics and Gerontology Neuroscience 030217 neurology & neurosurgery Developmental Biology |
| Zdroj: | Neurobiol Aging |
| Popis: | Aging often impairs cognitive functions associated with the medial temporal lobe (MTL). Anatomical studies identified the layer II pyramidal cells of the lateral entorhinal cortex (LEC) as one of the most vulnerable elements within the MTL. These cells provide a major excitatory input to the dentate gyrus hippocampal subfield by synapsing onto granule cells and onto local inhibitory interneurons, and a fraction of these contacts are lost in aged individuals with impaired learning. Using optogenetics we evaluated the functional status of the remaining inputs in an outbred rat model of aging that distinguishes between learning impaired and learning unimpaired individuals. We found that aging affects the pre- and postsynaptic strength of the LEC inputs onto granule cells. However, the magnitude these changes was similar in impaired and un-impaired rats. In contrast, the recruitment of inhibition by LEC activation was selectively reduced in the aged impaired subjects. These findings are consistent with the notion that the preservation of an adequate balance of excitation and inhibition is crucial for maintain proficient memory performance during aging. |
| Databáze: | OpenAIRE |
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