High-resolution MEMRI characterizes laminar specific ascending and descending spinal cord pathways in rats

Vijai Krishnan; Jiadi Xu; Albert German Mendoza; Alan Koretsky; Stasia A Anderson; Galit Pelled

doi:10.1016/j.jneumeth.2020.108748

High-resolution MEMRI characterizes laminar specific ascending and descending spinal cord pathways in rats

J Neurosci Methods. 2020 Jul 1:340:108748. doi: 10.1016/j.jneumeth.2020.108748. Epub 2020 Apr 23.

Authors

Vijai Krishnan¹, Jiadi Xu², Albert German Mendoza², Alan Koretsky³, Stasia A Anderson⁴, Galit Pelled⁵

Affiliations

¹ Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States; The Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States.
² Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States.
³ Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States.
⁴ National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States.
⁵ Department of Biomedical Engineering, Michigan State University, East Lansing, MI, United States; The Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, United States; Department of Radiology, Michigan State University, East Lansing, MI, United States; Johns Hopkins Medicine Department of Radiology and Radiological Science, Baltimore, MD, United States. Electronic address: pelledga@msu.edu.

Abstract

Background: The spinal cord is composed of nine distinct cellular laminae that currently can only be visualized by histological methods. Developing imaging methods that can visualize laminar architecture in-vivo is of significant interest. Manganese enhanced magnetic resonance imaging (MEMRI) yields valuable architectural and functional information about the brain and has great potential in characterizing neural pathways in the spinal cord. Here we apply MEMRI to visualize laminae architecture in the thoracic region of the spinal cord with ultra-high resolution.

New method: Manganese chloride (MnCl₂) was delivered systemically and imaging of the lumbar and thoracic spinal cord levels was acquired in high field, 11.7 T MRI scanner, 48 h following MnCl₂ administration.

Results: Here we demonstrate laminar specific signal enhancement in the spinal cord of rats administered with MnCl₂ with 69 μm in-plane resolution. We also report reduced T1 values over time in MnCl₂ groups across laminae IIX.

Comparisons with existing methods: This is the first study to demonstrate that MEMRI is capable of identifying spinal laminae at a high resolution of 69 μm in a living animal. This would enable the visualization of architecture and function of distinct regions with improved resolution, in healthy and diseased animal models.

Conclusions: The regions with the largest T1 enhancements were observed to correspond to laminae that contain either high cell density or large motor neurons, making MEMRI an excellent tool for studying spinal cord architecture, physiology and function in different animal models.

Keywords: Manganese enhanced magnetic resonance imaging; Motor neurons; Non-Invasive; Spinal cord.

Publication types

Research Support, N.I.H., Extramural
Research Support, N.I.H., Intramural

MeSH terms

Animals
Brain
Image Enhancement*
Magnetic Resonance Imaging*
Manganese
Rats
Spinal Cord / diagnostic imaging

Substances

Manganese

Abstract

Publication types

MeSH terms

Substances

Grants and funding