Figure 7.
SOM-positive and NPY-positive neuron counts in the dentate hilus and CA3 stratum oriens. A: Number of SOM-positive neurons in the dentate hilus is reduced in AI rats relative to young and AU animals. B: Number of SOM-positive neurons in the dentate hilus correlates with spatial memory function among the aged rat cohorts, r = 20.860, P < 0.001. C: Number of NPY-positive neurons in the hilus remains stable across the adult rat life span regardless of cognitive status. D: Number of SOM-positive neurons is reduced in CA3 stratum oriens of AU and AI rats relative to young. Error bars represent ± SEM. Y, young; AU, aged unimpaired; AU aged impaired; NPY, neuropeptide Y; SOM, somatostatin. *P < 0.001.