Age-related changes of deep-brain neurophysiological activity

Area of Science:

• Neuroscience
• Aging Research
• Cognitive Science

Background:

• Cognitive decline with aging is linked to brain atrophy and reduced activation, but mechanisms in deeper brain structures remain unclear.
• Healthy aging and neurodegenerative diseases often impact subcortical regions like the hippocampus, striatum, and thalamus.

Purpose of the Study:

• To characterize age-related changes in time-resolved, resting-state magnetoencephalography (MEG) activity in the hippocampus and subcortical regions.
• To investigate the neurophysiological mechanisms underlying cognitive variability in healthy aging.

Main Methods:

• Utilized resting-state magnetoencephalography (MEG) data from a large cohort of healthy young (20-30 years) and older (70-80 years) adults.
• Analyzed rhythmic and arrhythmic neural signal strength and frequency bands (delta, theta, alpha, gamma) in deeper brain structures, including the hippocampus, striatum, and thalamus.
• Correlated neurophysiological findings with short-term memory performance.

Main Results:

• Observed age-related changes in both rhythmic and arrhythmic signal strength across deeper brain regions.
• Detected a slowing of neural activity with age, characterized by increased delta and reduced gamma activity, mirroring cortical changes.
• Found a reduced occipito-parietal alpha peak and increased hippocampal theta activity, potentially indicating compensatory mechanisms, especially when short-term memory was preserved.

Conclusions:

• This study provides new insights into the evolution of hippocampal and subcortical neurophysiological activity with biological age.
• Highlights frequency-specific neural effects associated with cognitive decline versus cognitive maintenance in aging.
• Advances the understanding of the biological basis for inter-individual variability in cognitive aging.