September 1 (Mon.)
PLASTICITY OF THE BRAIN
Masao Ito (Frontier Research Program, RIKEN, Wako, Japan)
Recovery in motor functions from a damage in either peripheral or central nervous systems will occur in three directions. 1. Synaptic plasticity will enable intact brain tissues to acquire lost functions in the manner of learning. 2. Sprouting of axonal terminals will establish new neuronal connections in lesioned brain tissues to restore once lost functions. 3. Intact brain areas will reorganize motor plans to perform once impaired functions with a strategy different from that used by the lesioned tissues. In recent years, roles and mechanisms of the cerebellum in motor !earning have been uncovered. A characteristic type of synaptic plasticity, long-term depression (LTD), is a main process that accounts for learning capabilities of cerebellar tissues. LTD is induced by error signals conveyed by climbing fiber afferents to the cerebellum, and acts to reform neuronal circuits in the cerebellum toward minimization of the errors in movements. LTD is underlaid by complex reactions among receptors and messengers, which eventually lead to reduced agonist sensitivity of glutamate receptors due to phosphorylation. The phosphorylation is coupled with expression of immediate early genes which may lead to more permanent changes of synaptic efficacy. The LTD-based adaptive mechanism seems to serve for formation of a functional model of a motor system within the cerebellum. The model would enable us to perform movements without sensory feedback, or even without conscious attention. The model should be calibrated by daily exercise in order to keep the movement performed by referring to it precise and smooth. These cerebellar mechanisms could be implicated in rehabilitation.
INTERNATIONAL REIHABILITATION MEDICINE: COORDINATION AND COOPERATION
Martin Grabois (Baylor College of Medicine, Houston, Texas USA)
This presentation will address the historical basis for increased interaction of international rehabilitation medicine organizations including coordination of meetings, joint meetings and interlocking boards. The rationale for the eventual merge of the International Rehabilitation Medicine Association (IRMA) and the International Federation of Physical Medicine and Rehabilitation (IFPMR) into the International Society of Physical and Rehabilitation Medicine (ISPRM) will be presented.
It has become obvious with the significant issue facing international rehabilitation, a well organized, well financed and action oriented approach is needed. No single organization has the resources to accomplish this task.
By establishing the ISPRM, it is hoped and expected that we will have a more coordinated and cooperative approach to medical rehabilitation worldwide. This will be needed to increase interaction with the Rehabilitation International Medical Commission (RIMC) and perhaps in the future, to establish the ISPRM as the RIMC.