Metabolic Changes in Brain Slices over Time: a Multiplatform Metabolomics Approach.

Carolina Gonzalez-Riano,Gertrudis Perea,Coral Barbas,Candela González-Arias,Javier Defelipe,Silvia Tapia-González

doi:10.1007/s12035-020-02264-y

Abstract

Brain slice preparations are widely used for research in neuroscience. However, a high-quality preparation is essential and there is no consensus regarding stable parameters that can be used to define the status of the brain slice preparation after its collection at different time points. Thus, it is critical to fully characterize the experimental conditions for ex vivo studies using brain slices for electrophysiological recording. In this study, we used a multiplatform (LC-MS and GC-MS) untargeted metabolomics-based approach to shed light on the metabolome and lipidome changes taking place at different time intervals during the brain slice preparation process. We have found significant modifications in the levels of 300 compounds, including several lipid classes and their derivatives, as well as metabolites involved in the GABAergic pathway and the TCA cycle. All these preparation-dependent changes in the brain biochemistry related to the time interval should be taken into consideration for future studies to facilitate non-biased interpretations of the experimental results.

Highlights

Brain slice preparations are widely used for research in neuroscience for a variety of studies including those focusing on neuronal connectivity, synaptic transmission and plasticity, and electrical signaling [1]
Pioneering studies focusing on rat hippocampus slices did study such conditions, concluding that brain slices required up to 2.5 h to recover from the traumatic dissection process, achieving a steady metabolic and electrophysiological state, regardless of the temperature, glucose, or oxygen levels of slice incubation [11]
We have shown—for the first time in a preparation used for electrophysiological recordings—that complex changes in the metabolome and lipidome of brain slices take place in the cells after the brain slicing process and we have highlighted the potential impact that these metabolites would have on ex vivo studies

Summary

Introduction

Brain slice preparations are widely used for research in neuroscience for a variety of studies including those focusing on neuronal connectivity, synaptic transmission and plasticity, and electrical signaling [1]. It has been described that at least 3 h is required for synaptogenesis phenomena taking place in hippocampal slices to promote recovery an ultrastructural state closely resembling the initial in situ conditions [15] Another critical issue to deal with is the bacterial growth that dramatically reduces the lifespan of the brain slices due to the release of endotoxins such as lipopolysaccharide, which activates the tissue neurodegeneration, affecting cell survival [16]. Establishing such a consensus would help researchers to determine appropriate time windows for ex vivo experiments

Methods

Findings

Discussion

Conclusion