After an incomplete spinal cord injury, the body can partially recover basic motor function. So-called muscle spindles and associated sensory circuits back to the spinal cord promote the establishment of novel neuronal connections after injury.
This circuit-level mechanism behind the process of motor recovery was elucidated by Prof. Silvia Arber's research group at the Biozentrum, University of Basel and the Friedrich Miescher Institute for Biomedical Research. Their findings may contribute to designing novel strategies for treatment after spinal cord injuries and have now been published in the journal Cell.
Spinal cord injuries often lead to chronically impaired motor function. However, patients with incomplete spinal cord injury can partially regain their basic motor ability under certain circumstances. It is believed that remaining uninjured spinal cord tissue provides a substrate to form new circuits bridging the injury. How this formation of new connections is triggered and promoted has remained unclear until now.
In collaboration with Prof. Grégoire Courtine's research group at the EPFL in Lausanne, the team of Prof. Silvia Arber at the Biozentrum at the University of Basel and the Friedrich Miescher Institute for Biomedical Research (FMI) has demonstrated in a mouse model why paralyzed limbs can move again after incomplete spinal cord injuries: A specific sensory feedback channel connected to sensors embedded within the muscles – so-called muscle spindles – promotes the functional recovery of the damaged neuronal circuits in the spinal cord.
Muscle spindle sensory feedback provides trigger signal for recovery
Limb movement activates sensory feedback loops from the muscle to the spinal cord. This specific feedback channel promotes the repair process of the damaged spinal network after injury. As a result, basic motor function can be restored. “The sensory feedback loops from muscle spindles are therefore a key factor in the recovery process,” says Silvia Arber. After spinal cord injury, these nerve impulses keep providing information to the central nervous system – even when the transmission of information from the brain to the spinal cord no longer functions.
“An important trigger for the recovery process is the information conveyed from the muscle to the central nervous system and not only the top-down information the brain sends towards muscles,” explains the first author Aya Takeoka. In addition, the researchers demonstrated that only basic locomotor functionality could be restored spontaneously after an injury. Fine locomotor task performance tested, however, remained permanently lost.
Treatments must start with activation of muscle spindles
The study suggests that activation of muscle spindles is essential to promote the recovery process of damaged neuronal networks after spinal cord injury. Thus, therapeutic approaches should aim to extensively use the muscles, even if passively after an injury. The more intensely muscles are used in the movement process, the more muscle spindle feedback circuits are stimulated. By applying this principle, the repair of neuronal circuits and the accompanying recovery of basic motor skills will have the best chances of succeeding.
Info box: The muscle spindle
Muscle spindles are sensors in the skeletal muscles of the body, which are passively stretched or shortened by muscle expansion and contraction. Each of these muscle spindles, localized within a muscle, is contacted by sensory nerves. Sensory information is conveyed by these neurons directly from the muscles (e.g. from the arms or legs) back to the spinal cord. These transmitted impulses allow us, for example, to determine with closed eyes in which position our arms, legs, hands, and fingers are. In other words, to know where our whole body is positioned.
Aya Takeoka, Isabel Vollenweider, Grégoire Courtine, and Silvia Arber
Muscle Spindle Feedback Directs Locomotor Recovery and Circuit Reorganization after Spinal Cord Injury
• Prof. Dr. Silvia Arber, University of Basel, Biozentrum, phone: +41 61 267 20 57, email: firstname.lastname@example.org
• Heike Sacher, University of Basel, Biozentrum, Communications, phone: +41 61 267 14 49, E-Mail: email@example.com
Heike Sacher | Universität Basel
Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology
Scientists generate an atlas of the human genome using stem cells
24.04.2018 | The Hebrew University of Jerusalem
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
24.04.2018 | Information Technology
24.04.2018 | Earth Sciences
24.04.2018 | Life Sciences