The interaction between endogenous GABA, functional connectivity, and behavioral flexibility is critically altered...

Area of Science:

• Neuroscience
• Human Physiology
• Cognitive Aging

Background:

• Flexible behavior adjustment relies on dynamic nervous system control, which declines with age.
• Endogenous gamma-aminobutyric acid (GABA) influences behavioral efficiency, particularly in tasks requiring dynamic control.
• Aging impacts motor control flexibility and may be linked to altered GABAergic function.

Purpose of the Study:

• To investigate the relationship between endogenous GABA levels, interhemispheric connectivity, and behavioral flexibility during motor-state transitions in adults.
• To identify age-related differences in the neural mechanisms supporting flexible motor behavior.

Main Methods:

• Integration of behavioral analysis, assessment of interhemispheric phase-based connectivity during motor-state transitions, and measurement of endogenous GABA concentration.
• Utilized adult human volunteers to study dynamic motor-state transitions.

Main Results:

• Converging evidence indicates age-related differences in optimal endogenous GABA concentration for flexible behavior.
• Older participants exhibited increased interhemispheric connectivity during motor-state transitions.
• This increased connectivity is suggested to be a compensatory mechanism for age-related changes in inhibitory tone.

Conclusions:

• The findings suggest that increased interhemispheric connectivity in older adults may compensate for suboptimal inhibitory tone (GABAergic function) to maintain behavioral flexibility.
• This compensatory neural mechanism is crucial for upholding behavioral action flexibility in the context of healthy aging.
• Further research is needed to explore this interplay in other domains of flexible human behavior.