Transcriptomic Modification in the Cerebral Cortex following Noninvasive Brain Stimulation: RNA-Sequencing Approach

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Transcranial direct current stimulation (tDCS) is known to modulate neuroplasticity and shows therapeutic potential for psychiatric disorders.
• The molecular mechanisms underlying tDCS effects remain largely unexplored.
• Understanding gene expression changes is crucial for elucidating tDCS's impact on brain function.

Purpose of the Study:

• To investigate the effects of anodal tDCS on gene expression in the rat cerebral cortex.
• To determine if tDCS-induced gene expression changes are dependent on stimulation intensity.
• To identify specific molecular pathways affected by tDCS.

Main Methods:

• Anodal transcranial direct current stimulation (tDCS) was applied to rats at three distinct intensities.
• RNA-sequencing was performed on cerebral cortex tissue from stimulated and sham groups.
• Statistical analysis was used to identify differentially expressed genes and affected pathways.

Main Results:

• Approximately 1,000 genes showed statistically significant expression changes compared to the sham group at each tested intensity.
• tDCS significantly altered various functional pathways, biological processes, and molecular categories.
• Affected pathways included those related to inflammation, antidepressant action (GTP signaling, calcium ion binding, transmembrane/signal peptide), and neurotransmitter receptor signaling (serotonergic, adrenergic, GABAergic, dopaminergic, glutamatergic).
• Gene expression changes varied in a current intensity-dependent manner, with some alterations observed across multiple intensities and others unique to specific intensities.

Conclusions:

• Transcranial direct current stimulation (tDCS) demonstrably modifies gene expression profiles in the rat cerebral cortex.
• The observed alterations in gene expression are dependent on the intensity of the tDCS applied.
• These findings provide insights into the molecular underpinnings of tDCS, highlighting its impact on key signaling and inflammatory pathways.