Cortical and functional plasticity of hand grasping after a short period of immobilization

Michela here is working to better understand if a brief period of hand non-use may induce modifications in the motor performance during a grasping task and if cortical plastic changes occur in the brain. To this issue, we immobilized subjects’ hand with a soft bandage used in everyday clinical practice by physiotherapists.

A series of pilot experiments has been carried out in order

1. to fix the time of hand non-use
2. to determine the hand kinematic parameters to measure in the task
3. to select the objects to be grasped.

We compared an experimental group of healthy subjects, before and after the period of hand non-use in a grasping task. Kinematics of hand was measured with a motion capture device. In another group of subjects, the cortical representation map of the motor cortex was also studied with the Transcranial Magnetic Stimulation (TMS) before and after hand non-use. Moreover, some different learning tasks will be inserted during the period of immobilization to investigate the possibility to reverse hand non-use effects. Therefore, in a further experiment, the role of the ipsilateral hemisphere and interhemispheric inhibition (IHI) were also investigated. The study of the plasticity from a behavioral and a cortical point of view could be a good model to better understand how humans are able to adapt to the everyday experiences and to interact with the environment.

People: Michela Bassolino , M. Bove, Marco Jacono, Luciano Fadiga

GRASPING TASK: precision and power grip. Objects and markers' position.							HAND NON-USE: the participants were instruct to not move the hand and to wear a soft bandage.
CORTICAL REMAPPING: TMS  is used to evaluate the excitability map of the hand motor area in the brain.							THE TWO HEMISPHERES: We investigate, by means of the TMS, corticospinal excitability in both hemispheres and interhemispheric inhibition (IHI) from left to right and from right to left hand motor areas.

References:

M.Bassolino, M.Bove, L.Fadiga, T.Pozzo Functional and cortical plasticity after a brief period of hand immobilization Society for Neuroscience (SFN) Abstract, 380.9, Washington, DC November 2008.

M.Bassolino, M.Bove, L.Fadiga, T.Pozzo May a brief period of non-use modify “sense of hand”? Summer School, The sense of body. Bologna, June 16-21, 2008.

Bassolino, M.; Avanzino, L.; Pozzo, T.; Bove, M. Short term arm immobilization modulates cortical excitability and transcallosal interactions 60° Congresso Nazionale Società Italiana di Fisiologia, 2009