Volume and number of neurons of the human hippocampal formation in normal aging and Alzheimer's disease.

Abstract

In order to observe changes owing to aging and Alzheimer's disease (AD) in the volumes of subdivisions of the hippocampus and the number of neurons of the hippocampal formation, 18 normal brains from subjects who died of nonneurological causes and had no history of long-term illness or dementia (ten of these brains comprised the aged control group) and 13 AD brains were analyzed. An optimized design for sampling, measuring volume by using the Cavalieri principle, and counting the number of neurons by using the optical disector was implemented on 50 microns-thick cresyl-violet sections. The mean total volume of the principal subdivisions of the hippocampal formation (fascia dentata, hilus, CA3-2, CA1, and subiculum) showed a negative correlation with age in normal subjects (r = -0.56, 2P < 0.05), and a 32% mean reduction in the AD group compared with controls (P < 0.001). This finding supports the measurement of the coronal cross-sectional area and the volume of the hippocampal formation in the clinical diagnosis of AD. There was an inverse relationship between the age of normal subjects and the number of neurons in CA1 (r = -0.84, 2P < 0.0001) and subiculum (r = -0.49, 2P < 0.05) but not in other subdivisions. Pronounced AD-related reductions in neuron number were found only in the subiculum and the fascia dentata. Compared with controls, both losses represented 23% of neurons (P < 0.05). These results 1) confirm that AD is a qualitatively different process from normal aging and 2) reveal the regional selectivity of neuron loss within the hippocampal formation in aging and AD, which may be relevant to understanding the mechanisms involved in the neuron loss associated with the two processes.

Extracted Key Phrases

Showing 1-10 of 93 references

The role of cortical connectivity in Alzheimer's disease pathogenesis: A review and model system

  • M C Delacoste, C L White
  • 1993
Highly Influential
1 Excerpt

Fascia dentata du grand hippocampe dans le cerveau de l'homme

  • C H Giacomini
  • 1884
Highly Influential
1 Excerpt
Showing 1-10 of 101 extracted citations
050100150'99'01'03'05'07'09'11'13'15'17
Citations per Year

909 Citations

Semantic Scholar estimates that this publication has received between 533 and 1,442 citations based on the available data.

See our FAQ for additional information.