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Non-invasive Assessment of Changes in Corticomotoneuronal Transmission in Humans
Published on: May 24, 2017
Age-related differences in human corticospinal excitability during simple reaction time
Oron Levin1, Koen Cuypers, Yael Netz
1Research Center for Movement Control and Neuroplasticity, Department of Biomedical Kinesiology, Katholieke Universiteit Leuven, Heverlee, Belgium. oron.levin@faber.kuleuven.be
Neuroscience Letters
|October 12, 2010
Summary
Older adults show unique corticospinal (CS) excitability adjustments before responding. This study reveals selective CS tuning in older individuals, potentially speeding up reaction times.
Area of Science:
- Neuroscience
- Motor Control
- Human Aging
Background:
- Age-related cognitive decline can impact motor response initiation.
- Corticospinal (CS) tract facilitation is crucial for voluntary movements.
- Understanding age-related changes in motor control is vital for maintaining independence.
Purpose of the Study:
- To investigate age-related differences in corticospinal excitability during a simple reaction time task.
- To determine if older adults exhibit distinct patterns of motor cortex excitability modulation compared to younger adults.
- To explore the neural mechanisms underlying response generation in aging.
Main Methods:
- Single pulse transcranial magnetic stimulation (TMS) applied to the motor cortex.
- Measurement of motor evoked potentials (MEPs) in the abductor pollicis brevis (APB) muscle.
- Simple reaction time (SRT) task involving right and left hand movements in response to an auditory cue.
Main Results:
- Both young and old adults showed CS excitability facilitation around 100-120 ms before voluntary EMG onset for right-hand movements.
- Older adults exhibited pre-stimulus MEP facilitation for right-hand responses and reduced CS excitability for left-hand responses.
- These specific pre-stimulus modulations were not observed in young adults.
Conclusions:
- Older adults may employ selective pre-response modulation of corticospinal excitability to optimize reaction times.
- Age-related changes in motor control involve sophisticated neural adjustments rather than simple slowing.
- This pilot study highlights potential compensatory strategies in the aging motor system.
