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P1‐138: Distribution of BACE1 in the rodent, monkey and human brain
Author(s) -
Gobbi Luca,
Honer Michael,
Polara Alessandra,
Jacobsen Helmut,
Hartung Thomas,
Muri Dieter,
Esterhazy Daria,
Stoffel Markus,
Loetscher Hansruedi,
Borroni Edilio
Publication year - 2012
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2012.05.415
Subject(s) - dentate gyrus , human brain , rodent , amyloid precursor protein , bace1 as , neuroscience , hippocampus , biology , amyloid (mycology) , substantia nigra , pyramidal cell , alzheimer's disease , pathology , medicine , disease , ecology , dopaminergic , dopamine , botany
fully created a method to measure hippocampus volumes in live mice and serves as a first step toward understanding a possible biomarker for the disease. Methods: An in-vivo T 2 -weighted imaging method was developed with optimal contrast and resolution to allow for straightforward segmentation and volume determination of the hippocampus in mice. 7-month old, single transgenic mice, expressing either a chimeric mouse/human amyloid precursor protein (APP) mutation or a mutant human presenilin 1 (PS1) were imaged multiple times using 3D T 2 -weighted imaging on a 7T magnet (Figure 1) to establish the method and determine its accuracy. To calculate the volume, the hippocampus of each mouse was both manually segmented by three individuals and segmented with a semi-automated method (Figure 2). The images were also registered using an affine transformation to determine shape changes. Results: The hippocampus volumes ranged from 18 mm 3 to 23 mm 3 when done by the manual segmentation method. The semi-automated method gave 30% larger volumes as compared to the manual method (Figure 3). The kappa index, a measure of overlap between manually and automatically segmented brain structures, had values of > 0.86 for each compared image. The registration data showed that there were no significant shape changes for any of the hippocampi. Conclusions:A reliable method able to detect 1 mm 3 volume measurements when performed by a single individual was developed. The semi-automated segmentation was unable to detect differences. These results suggest that manual segmentation is still considered the most reliable segmentation method for small structures.