Figure 2.

Lipidomics analysis of individual neurons from mouse hippocampus. Representative nLC/MS tracings for (a) cholesterol ([M−H₂O + H]⁺, m/z = 369.35, Rt = 15.12 min), (b) hexosylceramide (d18:1/24:0) ([M + H]⁺, m/z = 812.69, Rt = 20.96), and (c) cholesterol ester 16:0 ([M + NH₄]⁺, m/z = 642.61, Rt = 25.22) obtained from a single DG granule cell. Black tracings: neurons; red tracings: artificial cerebrospinal fluid (ACSF). (d) Mass spectrum of cholesterol from a single DG granule cell. (e) Principal component analysis of lipids present in whole hippocampal tissue (orange triangles), single DG granule cells (blue triangles), single CA1 pyramidal cells (green triangles) and ACSF (yellow triangles). (f) Relative quantification of main lipid classes from individual neurons (blue circles; granule and pyramidal cells combined) and whole hippocampal tissue (orange circles). Abbreviations: CE, cholesteryl esters; DAG?, a lipid tentatively identified as diacylglycerol; GPL, glycerophospholipids; HexCer, hexosylceramides; SM, sphingomyelins. (g) Relative quantification of lipid species from individual neurons (blue bars) and whole hippocampal tissue (orange bars). Results are represented as mean ± s.e.m (n = 20 single neurons and 5 punches from different slices per group); *P < 0.05; **P < 0.005; ***P < 0.001; Mann-Whitney U test.