This is the clearest statement of something we all know but that most of the neuro research community seems oblivious of.

1: Rev Neurosci. 2007;18(3-4):209-22.

Stress as a modulator of motor system function and pathology.

Metz GA.

Canadian Centre for Behavioural Neuroscience, University of Lethbridge,
Lethbridge, Canada. gerlinde.metz@uleth.ca

Stress is one of the most significant influences on behaviour and performance.
The classical account is that stress mainly affects functions of the limbic
system, such as learning, memory and emotion. Recent evidence, however, suggests
that stress also modulates motor system function and influences the pathology of
movement disorders. Most parts of the motor system show the presence of
glucocorticoid receptors that render their circuits susceptible to the influence
of stress hormones. Stress and glucocorticoids have been shown to modulate
temporal and spatial aspects of motor performance. Skilled movements seem to be
most prone to stress-induced disturbances, but locomotion and posture can also be
affected. Stress can modulate movement through activation of the
hypothalamic-pituitary-adrenal axis and via stress-associated emotional changes.
The dopaminergic system seems to play a central role in mediating the effects of
stress on motor function. This route might also account for the finding that
stress influences the pathology of dopamine-related diseases of the motor system,
such as Parkinson's disease. Clinical observations have indicated that stress
might lead to the onset of Parkinsonian symptoms or accelerate their progression.
Glucocorticoids are modulators of neuronal plasticity, thus determining the
degree of structural and functional compensation of the damaged motor system.
This may particularly affect slowly progressive neurodegenerative diseases, such
as Parkinson's disease. That stress represents a significant modulator of motor
system function in both the healthy and the damaged brain should be recognized
when developing future therapies for neurodegenerative diseases.


PMID: 18019607 [PubMed - indexed for MEDLINE]