Functional segmentation of the hippocampus in the healthy human brain and in Alzheimer’s disease
NeuroImage. 2013-02-01; 66: 28-35
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1. Neuroimage. 2013 Feb 1;66:28-35. doi: 10.1016/j.neuroimage.2012.10.071. Epub 2012
Functional segmentation of the hippocampus in the healthy human brain and in
Zarei M(1), Beckmann CF(2), Binnewijzend MA(3), Schoonheim MM(3), Oghabian MA(4),
Sanz-Arigita EJ(3), Scheltens P(5), Matthews PM(6), Barkhof F(3).
(1)Institute for Cognitive Sciences Studies, Tehran, I.R., Iran. Electronic
(2)Donder Institute, Radbound University, Nijmegen, Netherlands.
(3)Radiology and Image Analysis Centre, VU Medical Centre, Amsterdam,
(4)Department of Neurology and Alzheimer Center, VU Medical Center, Amsterdam,
(5)Institute for Advanced Medical Technologies, Tehran University of Medical
Sciences, Tehran, Iran.
(6)Center for Neuroscience, Imperial College London, London, UK.
Neuroimage. 2013 Dec;83:1109.
In this study we segment the hippocampus according to functional connectivity
assessed from resting state functional magnetic resonance images in healthy
subjects and in patients with Alzheimer’s disease (AD). We recorded the resting
FMRI signal from 16 patients and 22 controls. We used seed-based functional
correlation analyses to calculate partial correlations of all voxels in the
hippocampus relative to characteristic regional signal changes in the thalamus,
the prefrontal cortex (PFC) and the posterior cingulate cortex (PCC), while
controlling for ventricular CSF and white matter signals. Group comparisons were
carried out controlling for age, gender, hippocampal volume and brain volume. The
strength of functional connectivity in each region also was correlated with
neuropsychological measures. We found that the hippocampus can be segmented into
three distinct functional subregions (head, body, and tail), according to the
relative connectivity with PFC, PCC and thalamus, respectively. The AD group
showed stronger hippocampus-PFC and weaker hippocampus-PCC functional
connectivity, the magnitudes of which correlated with MMSE in both cases. The
results are consistent with an adaptive role of the PFC in the context of
progression of dysfunction in PCC during earlier stages of AD. Extension of our
approach could integrate regional volume measures for the hippocampus with their
functional connectivity patterns in ways that should increase sensitivity for
assessment of AD onset and progression.
Copyright © 2012 Elsevier Inc. All rights reserved.
PMID: 23128076 [Indexed for MEDLINE]