Validating MALDI-IMS Feasibility in Ex Vivo Brain Slices

Area of Science:

• Neuroscience
• Analytical Chemistry
• Biochemistry

Background:

• Matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS) enables spatial detection and quantification of biomolecules in tissues.
• Lipid profiles are crucial for understanding neurologic diseases, and MALDI-IMS excels at high-resolution lipid imaging.
• Ex vivo brain slices are valuable models for studying neurologic conditions, but require optimized preparation for advanced analyses.

Purpose of the Study:

• To establish a reproducible protocol for lipidomic MALDI-IMS analysis of ex vivo rat brain slices.
• To validate that ex vivo brain slices preserve spatiochemical lipid profiles comparable to intact whole brains.
• To demonstrate a method for preparing 400 μm ex vivo brain slices for MALDI-IMS without compromising lipid integrity.

Main Methods:

• Development and validation of a protocol for preparing ex vivo rat brain slices for MALDI-IMS.
• Comparative analysis of lipid profiles in neocortex, striatum, and corpus callosum using ex vivo slices versus fresh frozen whole brains.
• Assessment of lipidomic integrity preservation during sample preparation and imaging.

Main Results:

• A feasible and reproducible protocol for lipidomic MALDI-IMS on ex vivo rat brain slices was established.
• Spatiochemical lipid profiles in ex vivo brain slices were found to be representative of intact whole brains.
• A technique was demonstrated for preparing 400 μm ex vivo brain slices for MALDI-IMS, preserving lipidomic integrity.

Conclusions:

• Ex vivo brain slices are a viable and reproducible platform for lipidomic MALDI-IMS studies in neuroscience.
• This protocol enables detailed spatial lipidomic analysis in neurologic disease research using ex vivo models.
• The findings provide a roadmap for utilizing MALDI-IMS on ex vivo brain slices in novel neuroscience applications.