A Review of ex vivo Elemental Mapping Methods to Directly Image Changes in the Homeostasis of Diffusible Ions (Na+, K+, Mg2 +, Ca2 +, Cl-) Within Brain Tissue

David Hartnell; Wendy Andrews; Nicole Smith; Haibo Jiang; Erin McAllum; Ramesh Rajan; Frederick Colbourne; Melinda Fitzgerald; Virginie Lam; Ryusuke Takechi; M Jake Pushie; Michael E Kelly; Mark J Hackett

doi:10.3389/fnins.2019.01415

A Review of ex vivo Elemental Mapping Methods to Directly Image Changes in the Homeostasis of Diffusible Ions (Na⁺, K⁺, Mg^{2 +}, Ca^{2 +}, Cl^-) Within Brain Tissue

Front Neurosci. 2020 Jan 22:13:1415. doi: 10.3389/fnins.2019.01415. eCollection 2019.

Authors

David Hartnell^{1

2

3}, Wendy Andrews^{1

2

3}, Nicole Smith⁴, Haibo Jiang⁴, Erin McAllum⁵, Ramesh Rajan⁶, Frederick Colbourne^{7

8}, Melinda Fitzgerald^{2

9

10}, Virginie Lam^{2

11}, Ryusuke Takechi^{2

11}, M Jake Pushie¹², Michael E Kelly¹², Mark J Hackett^{1

2

3}

Affiliations

¹ School of Molecular and Life Sciences, Faculty of Science and Engineering, Curtin University, Perth, WA, Australia.
² Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia.
³ Curtin Institute for Functional Molecules and Interfaces, Curtin University, Perth, WA, Australia.
⁴ School of Molecular Sciences, Faculty of Science, University of Western Australia, Perth, WA, Australia.
⁵ Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.
⁶ Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.
⁷ Department of Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AL, Canada.
⁸ Department of Psychology, Faculty of Arts, University of Alberta, Edmonton, AL, Canada.
⁹ School of Biological Sciences, University of Western Australia, Perth, WA, Australia.
¹⁰ Perron Institute for Neurological and Translational Science, Perth, WA, Australia.
¹¹ School of Public Health, Faculty of Health Sciences, Curtin University, Perth, WA, Australia.
¹² Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.

Abstract

Diffusible ions (Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl^-) are vital for healthy function of all cells, especially brain cells. Unfortunately, the diffusible nature of these ions renders them difficult to study with traditional microscopy in situ within ex vivo brain tissue sections. This mini-review examines the recent progress in the field, using direct elemental mapping techniques to study ion homeostasis during normal brain physiology and pathophysiology, through measurement of ion distribution and concentration in ex vivo brain tissue sections. The mini-review examines the advantages and limitations of specific techniques: proton induced X-ray emission (PIXE), X-ray fluorescence microscopy (XFM), secondary ion mass spectrometry (SIMS), laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and the sample preparation requirements to study diffusible ions with these methods.

Keywords: LA-ICP-MS; PIXE; SIMS; XFM; imaging; ischemia; metabolism; microprobe.

Publication types

Review