Postural Control in the Rabbit Maintaining Balance on the Tilting Platform
| Autor: | S. Grillner, Grigori N. Orlovsky, Tatiana G. Deliagina, Pavel V. Zelenin, Lyudmila B. Popova, Irina N. Beloozerova |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
medicine.medical_specialty
Physiology Movement Electromyography Kinematics Somatosensory system Tonic (physiology) Head-Down Tilt Physical medicine and rehabilitation Physical Stimulation Forelimb medicine Animals Muscle Skeletal Postural Balance Physics Vestibular system Communication medicine.diagnostic_test business.industry General Neuroscience Electric Stimulation Biomechanical Phenomena Hindlimb Ear Inner Sensory Thresholds Vestibule Coronal plane Rabbits Vestibule Labyrinth business Photic Stimulation |
| Zdroj: | Journal of Neurophysiology. 90:3783-3793 |
| ISSN: | 1522-1598 0022-3077 |
| Popis: | A deviation from the dorsal-side-up body posture in quadrupeds activates the mechanisms for postural corrections. Operation of these mechanisms was studied in the rabbit maintaining balance on a platform periodically tilted in the frontal plane. First, we characterized the kinematics and electromyographic (EMG) patterns of postural responses to tilts. It was found that a reaction to tilt includes an extension of the limbs on the side moving down and flexion on the opposite side. These limb movements are primarily due to a modulation of the activity of extensor muscles. Second, it was found that rabbits can effectively maintain the dorsal-side-up body posture when complex postural stimuli are applied, i.e., asynchronous tilts of the platforms supporting the anterior and posterior parts of the body. These data suggest that the nervous mechanisms controlling positions of these parts of the body can operate independently of each other. Third, we found that normally the somatosensory input plays a predominant role for the generation of postural responses. However, when the postural response appears insufficient to maintain balance, the vestibular input contributes considerably to activation of postural mechanisms. We also found that an asymmetry in the tonic vestibular input, caused by galvanic stimulation of the labyrinths, can affect the stabilized body orientation while the magnitude of postural responses to tilts remains unchanged. Fourth, we found that the mechanisms for postural corrections respond only to tilts that exceed a certain (threshold) value. |
| Databáze: | OpenAIRE |
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