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The Effects of Aging and Caloric Restriction upon Rat CA3 Hippocampus: A Three‐Dimensional Ultrastructural Study
Author(s) -
Donohue Howard Stephen,
Linville Constance,
Newton Isabel,
Adams Michelle,
BrunsoBechtold Judy
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.982.1
Subject(s) - ampa receptor , nmda receptor , hippocampal formation , synapse , hippocampus , glutamate receptor , excitatory postsynaptic potential , postsynaptic potential , neuroscience , biology , medicine , endocrinology , chemistry , receptor , inhibitory postsynaptic potential
We have previously shown an age‐related decline in glutamate receptor subunit levels in hippocampal CA3 that is altered by caloric restriction (CR). Specifically, CR beginning at 4 months of age results in a decline in NMDA and AMPA receptor subunits by 10 months of age to levels that remain stable across life‐span. By 28 months of age, subunits in ad libitum (AL) fed rats have declined to levels significantly lower than observed in CR animals. Moreover, cognitive performance in 28 month‐old CR rats is significantly better than in age‐matched AL animals. Because NMDA and AMPA receptor subunit levels as well as neural function have been correlated with area and complexity of hippocampal excitatory synapses, we used serial 3‐D reconstruction to assess size and morphology of postsynaptic densities (PSDs) in CA3 of young‐AL, aged‐AL and aged‐CR male F344×BN rats. Preliminary analysis reveals no difference in mean PSD surface area among groups. We also are quantifying the effects of age and CR on the overall synapse population in CA3 as well as on those with functionally‐relevant morphologies such as perforated synapses and multiple spine boutons.