Changes in white matter in mice resulting from low-frequency brain stimulation

Area of Science:

• Neuroscience
• Neurobiology
• Cellular Biology

Background:

• Learning and experience induce white matter changes in the brain.
• Meditation training alters white matter surrounding the anterior cingulate cortex.
• Low-frequency optogenetic stimulation of the anterior cingulate cortex in mice reduces anxiety-like behavior.

Purpose of the Study:

• Investigate the cellular mechanisms underlying the effects of low-frequency stimulation on white matter.
• Determine the impact of optogenetic stimulation on oligodendrocyte proliferation and myelin structure.
• Explore the relationship between white matter changes, neural connectivity, and behavior.

Main Methods:

• Utilized low-frequency optogenetic stimulation (1-8 Hz) targeting the anterior cingulate cortex in mice.
• Examined cellular changes in the corpus callosum, a major white matter tract.
• Assessed oligodendrocyte proliferation and measured the g-ratio of myelinated fibers.

Main Results:

• Low-frequency laser stimulation induced significant changes in subcortical white matter projection fibers within the corpus callosum.
• Oligodendrocyte proliferation increased following stimulation.
• A decreased g-ratio was observed, indicating myelin sheath thickening or axonal diameter changes.

Conclusions:

• Low-frequency stimulation promotes activity-dependent myelin remodeling in white matter.
• Enhanced myelin structure suggests improved neural connectivity.
• These findings link specific stimulation parameters to cellular changes, myelin plasticity, and behavioral outcomes, potentially informing therapeutic strategies for neurological conditions.