Affiliations: Institute for Neuroscience, The University of Texas at
Austin, Austin, TX, USA | Department of Psychology, The University of Texas at
Austin, Austin, TX, USA | Department of Neurosurgery, University of Michigan,
Ann Arbor, MI, USA | Henry Ford Health Science Center, Detroit, MI,
USA
Note: [] Corresponding author: Timothy Schallert, Ph.D. Department of
Psychology The University of Texas at Austin 1 University Station, #A8000
Austin, TX 78712, USA. Tel.: +1 512 471 6141; Fax: +1 512 232 4335; E-mail:
tschallert@mail.utexas.edu
Abstract: The effects of extreme disuse or overuse of the limbs in rat models
of Parkinson's disease and stroke are discussed. In unilaterally lesioned rats,
immobilizing one forelimb in a cast forces complete disuse of this limb and
extreme overuse of the uncasted limb. This procedure has diverse effects on
histological and behavioral outcomes in these models, depending upon how and
when it is applied relative to the lesion. Effects on behavioral outcome,
post-lesion plasticity events, and expression of trophic factors are discussed.
The effects of forced disuse or overuse vary among lesion types and can include
neuroprotection, changes in synaptogenesis, or even exaggeration of tissue
loss. The diversity of behavior-driven structural changes in the brain
underscores the potential importance of carefully tailoring physical
restorative therapy to specific neurological problems in order to optimize
outcomes. In addition, we stress the need to recognize the reciprocal influence
that behavior and the brain can have upon each other.
