Objectives: GABA is the most important inhibitory neurotransmitter. Thus, variation in its concentration is connected to a wide variety of diseases. However, the low concentration and the overlap of more prominent resonances hamper GABA quantification using MR spectroscopy. The hippocampus plays a pivotal role in neurodegeneration. Susceptibility discontinuities in the vicinity of the hippocampus cause strong B inhomogeneities, impeding GABA spectroscopy. The aim of this work is to improve the reproducibility of hippocampal GABA+ MRS.
Methods: The GABA+/total creatine ratio in the hippocampus was measured using a MEGA-sLASER sequence at 7 Tesla. 10 young healthy volunteers participated in the study. A dedicated pre-processing approach was established. Spectral quantification was performed with Tarquin. The quantification parameters were carefully adjusted to ensure optimal quantification.
Results: An inter-subject coefficient of variation of the GABA+/total creatine of below 15% was achieved. Additional to spectral registration, which is essential to obtain reproducible GABA measures, eddy current compensation and additional difference artifact suppression improved the reproducibility. The mean FWHM was 23.1 Hz (0.078 ppm).
Conclusion: The increased spectral dispersion of ultra-high-field spectroscopy allows for reproducible spectral quantification, despite a very broad line width. The achieved reproducibility enables the routine use of hippocampal GABA spectroscopy at 7 Tesla.
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http://dx.doi.org/10.1007/s10334-020-00879-9 | DOI Listing |
Alzheimers Dement
January 2025
Computational Brain Research and Intervention (C-Brain) Lab, Department of Psychiatry and Behavioral Sciences, School of Medicine, Stanford University, Stanford, California, USA.
Introduction: Amyloid beta (Aβ) plaques and hyperphosphorylated tau in the entorhinal regions are key Alzheimer's disease (AD) markers, but the spatial Aβ pathways influencing tau pathology remain unclear.
Methods: We applied predictive modeling to identify Aβ standardized uptake value ratio (SUVR) spatial patterns that predict entorhinal tau levels, future hippocampal volume, and Preclinical Alzheimer's Cognitive Composite (PACC) scores at 5-year follow-up. The model was trained on Alzheimer's Disease Neuroimaging Initiative (ADNI) (N = 237), incorporating amyloid-PET (positron emission tomography), tau-PET, magnetic resonance imaging (MRI), and cognitive data, and validated on Harvard Aging Brain Study (HABS) (N = 276).
Cells
December 2024
Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Accurate normalization in miRNA studies requires the use of appropriate endogenous controls, which can vary significantly depending on cell types, treatments, and physiological or pathological conditions. This study aimed to identify suitable endogenous miRNA controls for neural progenitor cells (NPCs) and hippocampal tissues, both of which play crucial roles in neurogenesis. Using small RNA sequencing, we identified the most stable miRNAs in primary mouse NPCs and hippocampal tissues and accessed their stability using NormFinder analysis.
View Article and Find Full Text PDFHum Brain Mapp
December 2024
Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
The human hippocampus is a key region in cognitive and emotional processing, but also a vulnerable and plastic region. Accordingly, there is a great interest in understanding how variability in the hippocampus' structure relates to variability in behavior in healthy and clinical populations. In this study, we aimed to link interindividual variability in subregional hippocampal networks (i.
View Article and Find Full Text PDFHum Brain Mapp
October 2024
Institute of Gerontology, Wayne State University, Detroit, Michigan, USA.
Inquiries into properties of brain structure and function have progressed due to developments in magnetic resonance imaging (MRI). To sustain progress in investigating and quantifying neuroanatomical details in vivo, the reliability and validity of brain measurements are paramount. Quality control (QC) is a set of procedures for mitigating errors and ensuring the validity and reliability of brain measurements.
View Article and Find Full Text PDFHippocampus
December 2024
Program in Neuroscience & Behavior, Mount Holyoke College, South Hadley, Massachusetts, USA.
The hippocampus (HC) is recognized for its pivotal role in memory-related plasticity and facilitating adaptive behavioral responses to reward shifts. However, the nature of its involvement in the response to reward downshifts remains to be determined. To bridge this knowledge gap, we explored the HC's function through a series of experiments in various tasks involving reward downshifts and using several neural manipulations in rats.
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