Objective To study the effect of normal aging on human hippocampus and
entorhinal cortex with the comparative method of MRI and histology. Methods MRIbased area
measurements through several special coronal levels(anterior commisure, mamillary body and
lateral genicular nucleus)of the hippocampus and entorhinal cortex were measured; the using
imaging analyzer, we counted neuronal density of the hippocampus and entorhinal cortex on
the same coronal levels. Results The MRIbased area measurements indicated that in normal
aging, there was no significant agerelated atrophy in the hippocampus and entorhinal cortex.
The result showed that the neuronal density kept constant during normal aging; while the
MRIbased area measurements correlated with those after preparation. ConclusionIn the
hippocampus and entorhinal cortex, there was without no the decrease of the volumes or the
loss of the neurons on special levels during normal aging.It was considered that the MRIbased
area measurements of the hippocampus and entorhinal cortex might be of value for early
diagnosis of some degenerative diseases of the CNS.