Neuroscience letters
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Neuroscience letters · Apr 2012
Evaluation of the effects of treatment with sAPPα on functional and histological outcome following controlled cortical impact injury in mice.
Treatment with sAPPα, the product of non-amyloidogenic processing of the amyloid precursor protein (APP) has been shown to be protective following diffuse traumatic brain injury (TBI), by improving motor outcome and reducing axonal injury. However the effects of treatment with sAPPα following a focal TBI have yet to be determined. ⋯ However the effect of treatment with sAPPα was not as dramatic as that seen previously following a diffuse injury. Nonetheless, these improvements in functional outcome were acompanied by a small but significant improvement in the amount of cortical and hippocampal at 7 days post-injury, and provide further support for the efficacy of sAPPα as a potential neuroprotective agent following TBI.
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Neuroscience letters · Apr 2012
Influence of somatosensory input on corticospinal excitability during motor imagery.
Our previous studies showed that corticospinal excitability during imagery of squeezing a foam ball was enhanced by somatosensory input generated by passively holding the ball. In the present study, using the same experimental model, we investigated whether corticospinal excitability was influenced by holding the object with the hand opposite to the imagined hand. ⋯ The MEPs amplitude during motor imagery was increased, only when the holding hand and the imagined hand were on the same side. These results suggest that performance improvement and rehabilitation exercises will be more effective when somatosensory stimulation and motor imagery are done on the same side.
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Neuroscience letters · Apr 2012
BDNF as an effect modifier for gender effects on pain thresholds in healthy subjects.
BDNF is an important marker of neuronal plasticity. It has also been associated with pain processing. Increased BDNF levels are observed in chronic pain syndromes. ⋯ These effects were not observed when gender was analyzed alone. These finding suggests that experimental heat and pressure pain threshold is gender-related and BDNF dependent. In fact BDNF has a facilitatory effect on pain threshold in females but has an opposite effect in males; supporting the notion that BDNF is an effect modifier of the gender effects on pain threshold in healthy subjects.
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Neuroscience letters · Apr 2012
Periaqueductal gray stimulation suppresses spontaneous pain behavior in rats.
Methods for evaluating analgesic effect for spontaneous pain are increasingly important because it is reported by most patients with neuropathic pain. The present study assessed the analgesic effects of periaqueductal gray (PAG) stimulation in the spared nerve injury (SNI) model of neuropathic pain of the rat. Spontaneous rapid paw withdrawal movements were used as the index of spontaneous pain. ⋯ Both analgesic effects lasted 30-40min beyond the 3min stimulation period. In summary, PAG stimulation was effective in alleviating spontaneous pain and mechanical allodynia in the SNI rat. The frequency of spontaneous paw lifting, a behavioral index of spontaneous pain used in this study, will be useful for future testing of therapeutic methods.
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Neuroscience letters · Apr 2012
Diffusion tensor imaging detects axonal injury in a mouse model of repetitive closed-skull traumatic brain injury.
Mild traumatic brain injuries (TBI) are common in athletes, military personnel, and the elderly, and increasing evidence indicates that these injuries have long-term health effects. However, the difficulty in detecting these mild injuries in vivo is a significant impediment to understanding the underlying pathology and treating mild TBI. In the following experiments, we present the results of diffusion tensor imaging (DTI) and histological analysis of a model of mild repetitive closed-skull brain injury in mouse. ⋯ In addition to the white matter alterations, mean diffusivity was elevated in ipsilateral cortex at 24h but returned to sham levels by 7 days. Altogether, this demonstrates that DTI is a sensitive method for detecting axonal injury despite a lack of conventional APP pathology. Further, this reflects a need to better understand the histological basis for DTI signal changes in mild TBI.