Brain lipid changes after repetitive transcranial magnetic stimulation: potential links to therapeutic effects?

Abstract

Repetitive transcranial magnetic stimulation (rTMS) is increasingly used in the management of neurologic disorders such as depression and chronic pain, but little is known about how it could affect brain lipids, which play important roles in membrane structure and cellular functions. The present study was carried out to examine the effects of rTMS on brain lipids at the individual molecular species level using the novel technique of lipidomics. Rats were subjected to high frequency (15 Hz) stimulation of the left hemisphere with different intensities and pulses of rTMS. The prefrontal cortex, hippocampus and striatum were harvested 1 week after rTMS and lipid profiles analyzed by tandem mass spectrometry. rTMS resulted in changes mainly in the prefrontal cortex. There were significant alterations in plasmalogen phosphatidylethanolamines, phosphatidylcholines, and increases in sulfated galactosylceramides or sulfatides. Plasmalogen species with long chain polyunsaturated fatty acids (PUFAs) showed decrease in abundance together with corresponding increase in lysophospholipid species suggesting endogenous release of long chain fatty acids such as docosahexaenoic acid (DHA) in brain tissue. The hippocampus showed no significant changes, whilst changes in the striatum were often opposite to that of the prefrontal cortex. It is postulated that changes in brain lipids may underlie some of the clinical effects of rTMS.

Extremely low frequency electromagnetic field exposure and restraint stress induce changes on the brain lipid profile of Wistar rats

“…According to our results, Oliveira [ 29 ] found POL changes in cortex and cerebellum after deep chronic stress, sphingolipid and phospholipid metabolism were deeply affected, showing a decrease in: phosphatidylethanolamine, ether phosphatidylcholine, and an increase in lysophosphatidylethanolamine levels similar to Lee et al [ 32 ].…”

Repetitive Transcranial Magnetic Stimulation (rTMS) Modulates Lipid Metabolism in Aging Adults

“…For example, rTMS normalized prefrontal dysfunctions and cognitive-related metabolic profiling in aged mice (Wang H. L. et al, 2016 ). Besides, Lee et al ( 2012 ) found that the effects of rTMS are related to changes in the brain lipids. In human studies, it also has been found that rTMS affects cortical metabolism (Bohning et al, 1999 ; Kimbrell et al, 2002 ).…”

Role of the Prefrontal Cortex in Pain Processing

“…Since ketamine is an inhibitor of NMDA receptors, this suggests that rTMS-induced antinociception is dependent on NMDA receptors and may involve long-term potentiation (LTP) mechanisms [ 250 ]. Lipidomic analysis of the PFC of rats after rTMS indicate loss of plasmalogen species with long-chain polyunsaturated fatty acids, with an increase in their corresponding lysophospholipids, suggesting endogenous release of long-chain fatty acids such as docosahexaenoic acid (DHA) after rTMS [ 251 ]. DHA may be metabolized to resolvin D1 by 15-lipoxygenase-1 (Alox15), which has been shown to play an important role in LTP [ 252 , 253 ] and antinociception [ 252 , 253 ] .…”