In Vitro Effects of Electrical Stimulation on Neural Membrane Lipid Plasticity
Project no. 22929 · Status: Kapanmış (Yayın bekleniyor) · 2021
Summary
<p>Changes in the excitability of neurons have been shown to be among the causes of many neurological disorders, with epilepsy being the most typical. The epileptogenesis mechanism manifests itself as a result of mechanisms that are not fully understood today and are likely to involve multiple factors. Changes in neuron excitability observed in epilepsy cause neurons to depolarize rapidly and abruptly during seizures. As a result, intense fluctuations in the electrical field may lead to plastic changes in neuron cell membranes. Most studies trying to explain changes in neuron excitability have attributed them to plastic changes in protein-made ion channels and synaptic connections, but the cause of these changes has not been fully elucidated. The lipid profile of the plasma membrane, which is expected to affect the capacitive property of the neuron membrane, is generally ignored by researchers. Therefore, it is necessary to determine the possible effects of electrical field potential changes observed during epileptic seizures on the membrane lipid composition. Upon reviewing the literature, we have not come across a study that performed detailed lipid analysis in experiments that generated electrical fields in neurons.</p><p>Based on this information and predictions, we hypothesize that electrical field potential changes that occur during in vitro neural excitation will cause changes in the lipid profile, which plays a decisive role in the membrane's capacitive property. To test this hypothesis, a study was conducted to determine the effect of pulsed current electrical field potentials (PCEFs) generated in vitro on the membrane lipid composition. In this context, experimental setups were developed that were compatible with the Biopac system, which can perform in vitro stimulation and is used in electrophysiological experiments. Electrical stimulation was applied to primary neurons and SH-SY5Y cell cultures using different stimulation parameters through the experimental setups, and their membrane lipid profiles were analyzed using high-performance liquid chromatography (HPLC) after the study. The results were analyzed using one-way analysis of variance (ANOVA). When the variance between the groups was homogeneous in the variables where the difference was found significant, the Tukey test was applied as a post-hoc method, and the Post-Hoc Dunnett T3 test was applied when the variance was not homogeneous between the groups.</p><p>As a result of the study, it was observed that the electrical field potentials generated on primary neurons and neuron-derived SH-SY5Y cells caused changes in the membrane lipid profiles of both cell types. The responses of cholesterol and phosphatidylethanolamine (PE) molecules to electrical field stimulation are particularly important among the lipid types. It was determined that the concentration of cholesterol decreased in primary neurons with high-intensity electrical field stimulation, while the PE levels in the cell membrane increased. The decrease in cholesterol levels in neuron membranes under high-intensity electrical field stimulation is a type of cellular response developed to protect against events that threaten cell viability, such as excitotoxicity.</p>