Secondary Ion Mass Spectrometry Imaging Reveals Changes in the Lipid Structure of the Plasma Membranes of Hippocampal Neurons following Drugs Affecting Neuronal Activity

Abstract

The cellular functions of lipids in the neuronal plasma membranes have been increasingly acknowledged, particularly their association to neuronal processes and synaptic plasticity. However, the knowledge of their regulatory mechanisms in neuronal cells remains sparse. To address this, we investigated the lipid organization of the plasma membranes of hippocampal neurons in relation to neuronal activity using secondary ion mass spectrometry imaging. The neurons were treated with drugs, particularly tetrodotoxin (TTX) and bicuculline (BIC), to induce chronic activation and silencing. Distinct lipid organization was found in the plasma membrane of the cell body and the neurites. Moreover, significant alterations of the levels of the membrane lipids, especially ceramides, phosphatidylserines, phosphatidic acids, and triacylglycerols, were observed under the TTX and BIC treatments. We suggest that many types of membrane lipids are affected by, and may be involved in, the regulation of neuronal function.

Early Life Exposure to C16-Ceramide Improves Learning and Short-Term Memory Behavior during Adulthood in Mice

“…In particular, the fluidity of cell membranes could be affected by C 16 -ceramide, which highlights the versatile role that ceramides play in cell membrane events . Indeed, changes in the lipid composition of membranes regulate neuronal activity . Therefore, one hypothesis is that C 16 -ceramide participates in formation of lipid rafts through which it then modulates channels such as NMDAR and these in turn regulate downstream molecules.…”

Chemical Imaging and Analysis of Single Nerve Cells by Secondary Ion Mass Spectrometry Imaging and Cellular Electrochemistry

“… Agüi-Gonzalez et al (2021) investigated the effect of neuronal activity alterations on the lipid organization of the plasma membrane in primary hippocampal neurons. First, the spatial organization of lipids and lipid fragments across different parts of the cellular membrane was assessed.…”

“…Tandem MS SIMS, such as the recently developed OrbiSIMS ( Passarelli et al, 2017 ), will be useful for elucidating molecular structures in complex molecular compositions of neurons and synapses. In addition, development of labeling tools for large biomolecules, such as proteins ( Kabatas et al, 2019 ; Agüi-Gonzalez et al, 2021 ), will allow for targeted imaging of multiple proteins and lipids by SIMS at the single synapse level. Furthermore, standardization of data treatment and statistical analysis, as well as development of mass peak databases specific for neurons and synapses will ensure reliable data handling and interpretation performed by those who are not SIMS experts.…”

“…Unlike fluorescence imaging, SIMS allows for a label-free approach and elucidation of molecular structure (ToF-SIMS), although isotopic labeling is often employed to track the molecular turnover of cells and organelles ( Lanekoff et al, 2011 ; Steinhauser et al, 2012 ). SIMS has continuously expanded its horizon of applications to study biomolecular organization in cell biology and neuroscience ( Thomen et al, 2020 ; Agüi-Gonzalez et al, 2021 ; Jähne et al, 2021 ).…”

Selective Capture-Based Single-Cell Mass Spectrometry for Enhancing Sphingolipid Profiling of Neurons with Differentiation of Cell Body from Synapse

“…To achieve single-cell resolution in MS, various spatially resolved sampling or ionization techniques were developed. Matrix-assisted laser desorption ionization (MALDI) and secondary ion MS (SIMS) are widely used spatially resolved ionization methods in single-cell analysis and have been used to provide phospholipid profiling of single cells and even the subcellular spatial distribution of phospholipids. − However, they are generally operated under vacuum conditions and are not suitable for living cell analysis. In recent years, different ambient sampling methods coupled with electrospray ionization (ESI) were developed for single-cell analysis in ambient conditions or even in living cells, including directly drawing the cytoplasm from a cell using a micropipette, capillary microsampling or patch clamp techniques, ambient liquid extraction by droplet extraction, , single-probe, , T-probe , and nanospray desorption ESI (nanoDESI), and in vivo solid-phase microextraction (SPME) via probe ESI (PESI). , Among them, ambient liquid extraction techniques could achieve solvent extraction of cellular contents during sampling, resulting in higher coverage of insoluble compounds in or out of the cytoplasm.…”