Neuroscience
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The benefits of Cochlear implant (CI) technology depend among other factors on the proximity of the electrode array to the spiral ganglion neurons. Laminin, a component of the extracellular matrix, regulates Schwann cell proliferation and survival as well as reorganization of actin fibers within their cytoskeleton, which is necessary for myelination of peripheral axons. In this study we explore the effectiveness of laminin-coated electrodes in promoting neuritic outgrowth from auditory neurons towards the electrode array and the ability to reduce acoustic and electric auditory brainstem response (i.e. aABR and eABR) thresholds. ⋯ In vivo: Animals implanted with laminin-coated electrodes experience significant decreases in eABR and aABR thresholds at selected frequencies compared to the results from the uncoated electrodes group. At 1 month post implantation there were a greater number of spiral ganglion neurons and neuritic processes projecting into the scala tympani of animals implanted with laminin-coated electrodes compared to animals with uncoated electrodes. These data suggest that Schwann cells are attracted towards laminin-coated electrodes and promote neuritic outgrowth/ guidance and promote the survival of spiral ganglion neurons following electrode insertion trauma.
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Randomized Controlled Trial
The Role of S100B in Aerobic Training Efficacy in Older Adults with Mild Vascular Cognitive Impairment: Secondary Analysis of a Randomized Controlled Trial.
Aerobic training improves cognitive and brain outcomes across different populations and neurocognitive disorders of aging, including mild subcortical ischemic vascular cognitive impairment (SIVCI). However, little is known of the underlying mechanisms through which aerobic training exerts its beneficial effects on the brain. Recently, S100 calcium-binding protein B (S100B) has been proposed as a possible mediator of aerobic training. ⋯ At trial completion, aerobic training decreased circulating levels of S100B compared with usual care plus education. Furthermore, reduced S100B levels were associated with improved global cognitive function in those who received the aerobic exercise intervention. Together these findings suggest that S100B is a promising target mediating the beneficial effects of moderate-intensity aerobic training on brain health in older adults with mild SIVCI.
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Randomized Controlled Trial
Upper Limb Motor Training Based on Task-Oriented Exercises Induces Functional Brain Reorganization in Patients with Multiple Sclerosis.
The aim of this work was to investigate changes in motor performance and in the brain activation pattern during finger movements, following upper limb motor training in multiple sclerosis. Thirty people with multiple sclerosis with mild upper limb sensorimotor deficits were randomly allocated to one of two groups: the experimental group (n = 15) received an upper limb treatment based on voluntary task-oriented movements; the control group (n = 15) underwent passive mobilization of shoulder, elbow, wrist and fingers. All participants completed three treatment sessions per week for eight weeks. ⋯ However, only the experimental group showed increased lateralization towards more normal brain activation following treatment, with activation clusters mainly located in the left brain hemisphere and right cerebellum. In conclusion, both active and passive interventions were effective in improving motor performance. However, only the treatment based on voluntary task-oriented movements could induce changes in brain activity that may have reflected skill acquisition by the right hand, reducing the activation of compensatory areas and decreasing brain resource demand.
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Acute aerobic exercise induces short-term neuroplasticity, although it remains unknown whether biological sex and ovarian hormones influence this response. The present study investigated the effects of biological sex and ovarian hormones on short-term neuroplasticity induced by acute aerobic exercise. Young active adults (n = 17 males and n = 17 females; 21 ± 2 years) participated in two sessions in which transcranial magnetic stimulation (TMS) measures were acquired immediately before and after a 20-min bout of moderate-intensity cycling at 65-70% of maximal heart rate. ⋯ SIGNIFICANCE STATEMENT: Acute exercise induces short-term changes indicative of neuroplasticity within the primary motor cortex and corticospinal pathway. This research reveals that increases in corticospinal excitability and decreases in intracortical inhibition occur similarly in males and females, and that female hormones do not influence these changes. These findings may be used to assist with developing exercise interventions aimed at promoting neuroplasticity in both sexes.