Figure 1.

Dimethylethanolamine (DMEA) decreases spontaneous neuronal activity in neuronal cultures in a concentration-dependent manner. Activity of cultured hippocampal neurons (DIV 13–16) was investigated in current-clamp mode in the absence or presence of DMEA. During baseline conditions, all neurons displayed excitatory synaptic events with associated action potentials (APs) at a frequency of ~1 Hz. Both AP, as well as large amplitude synaptic event frequency, decreased with increasing DMEA concentration to reach a full block with 5 mM DMEA. (A,D) Exemplary recordings in neurons with application of 0.0, 0.5, 2.0 and 5.0 mM DMEA (A) or 10 mM DMEA (D); note that due to experimental setup we could not perform repeated measurement in one cell including all concentrations and present the results here separately; Dashed lines below recordings indicate resting membrane potential (RMP, in mV) of cells. (B,E) DMEA significantly decreases event frequency in a concentration-dependent manner. (C,F) Application of DMEA does not affect RMP. All data are shown as scatter plots with median and interquartile range. Asterisks mark significant differences as assessed by Friedman test and post hoc by Dunnett’s multiple comparison of groups (B,C) or by Wilcoxon signed-rank test (E,F; *p < 0.05, **p < 0.01, ***p < 0.001). Scale bar: 10 mV, 0.5 s.