TY - JOUR
T1 - Cognitive decline is associated with reduced reelin expression in the entorhinal cortex of aged rats
AU - Stranahan, Alexis M.
AU - Haberman, Rebecca P.
AU - Gallagher, Michela
N1 - Funding Information:
National Institute on Aging at the National Institutes of Health (T32 AG027668-02 to A.M.S.); Ford Foundation/National Research Council Fellowship to A.M.S.; National Institute on Aging at the National Institutes of Health (5P01AG009973-17 to M.G.)
PY - 2011/2
Y1 - 2011/2
N2 - Brain regions and neural circuits differ in their vulnerability to changes that occur during aging and in age-related neurodegenerative diseases. Among the areas that comprise the medial temporal lobe memory system, the layer II neurons of the entorhinal cortex, which form the perforant path input to the hippocampal formation, exhibit early alterations over the course of aging Reelin, a glycoprotein implicated in synaptic plasticity, is expressed by entorhinal cortical layer II neurons. Here, we report that an age-related reduction in reelin expression in the entorhinal cortex is associated with cognitive decline. Using immunohistochemistry and in situ hybridization, we observed decreases in the number of Reelin-immunoreactive cells and reelin messenger RNA expression in the lateral entorhinal cortex of aged rats that are cognitively impaired relative to young adults and aged rats with preserved cognitive abilities. The lateral entorhinal cortex of aged rats with cognitive impairment also exhibited changes in other molecular markers, including increased accumulation of phosphorylated tau and decreased synaptophysin immunoreactivity. Taken together, these findings suggest that reduced reelin expression, emanating from layer II entorhinal neurons, may contribute to network dysfunction that occurs during memory loss in aging.
AB - Brain regions and neural circuits differ in their vulnerability to changes that occur during aging and in age-related neurodegenerative diseases. Among the areas that comprise the medial temporal lobe memory system, the layer II neurons of the entorhinal cortex, which form the perforant path input to the hippocampal formation, exhibit early alterations over the course of aging Reelin, a glycoprotein implicated in synaptic plasticity, is expressed by entorhinal cortical layer II neurons. Here, we report that an age-related reduction in reelin expression in the entorhinal cortex is associated with cognitive decline. Using immunohistochemistry and in situ hybridization, we observed decreases in the number of Reelin-immunoreactive cells and reelin messenger RNA expression in the lateral entorhinal cortex of aged rats that are cognitively impaired relative to young adults and aged rats with preserved cognitive abilities. The lateral entorhinal cortex of aged rats with cognitive impairment also exhibited changes in other molecular markers, including increased accumulation of phosphorylated tau and decreased synaptophysin immunoreactivity. Taken together, these findings suggest that reduced reelin expression, emanating from layer II entorhinal neurons, may contribute to network dysfunction that occurs during memory loss in aging.
KW - Alzheimer's disease
KW - aging
KW - lateral entorhinal cortex
KW - learning
KW - mild cognitive impairment
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U2 - 10.1093/cercor/bhq106
DO - 10.1093/cercor/bhq106
M3 - Article
C2 - 20538740
AN - SCOPUS:78651480561
SN - 1047-3211
VL - 21
SP - 392
EP - 400
JO - Cerebral Cortex
JF - Cerebral Cortex
IS - 2
ER -