High intensity reaching and grasping rehabilitation therapy in spinal cord injured rats
Regaining lost arm and hand function is a gateway to independence for many spinal cord injured (SCI) individuals since reaching and grasping are essential for a number of daily tasks. Following SCI, damage to spinal networks results in a loss of motor function, which can lead to progressive changes to muscle physiology and further decline in motor function. The most effective treatment for regaining reaching and grasping abilities after cervical SCI is rehabilitative (rehab) therapy. Although it is generally recognized that more rehab therapy leads to greater recovery, it is surprising that the optimal intensity and timing of these therapies are unknown. Moreover, the physiological mechanisms underlying the therapeutic benefits of rehab therapy remain largely unknown. This study aims to establish optimal parameters for rehab therapy for reaching and grasping and to examine the effects optimized therapy has on spinal neural networks and muscle physiology in sub-acute and chronic SCI rats.
Until recently it was not possible to provide high-intensity rehab reaching and grasping therapy to animals mainly because of the excessive amounts of time required to train individual animals in reaching tasks. To overcome this hurdle my lab recently developed a novel automated robotic system that trains and assesses reaching and grasping in rats. This system allows the animals to train ad libitum 24 hours a day, 7 days a week, thus mimicking a full range of training intensities (including high-intensity rehab therapy). We will use these devices to determine optimal reaching and grasping rehab therapy strategies and explore at these intensive training levels the physiological mechanism that are linked to improved function. Understanding these relations will allow us to exploit and amplify these mechanisms in the future.
The experiments laid out in this proposal are crucial for developing optimized strategies for rehab therapy. Until now it is completely unknown where the limits of rehab training are because it is generally acknowledged that we undertrain in animal models as well as in the clinical setting. Thus although we cannot directly translate the optimal amount and timing of training from the rat to humans, we can now explore these boundaries. Furthermore, once the maximal beneficial intensity of training is reached, we can better study possible side effects and mechanisms that translate training into recovery.
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