Neuroreport
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The anti-migraine agent sumatriptan constricts cerebral blood vessels, and also blocks neuropeptide release from meningeal sensory neurons. We investigated whether sumatriptan can also affect neuronal discharge, by recording the activity of dural primary afferent neurons during dural application of sumatriptan in anesthetized rats. ⋯ The suppressive effect of calcium removal was not a result of a general decrease in excitability, because calcium removal produced a pronounced increase in mechanically evoked discharge. The excitatory effect on dural afferent discharge might underlie the initial worsening of the headache that can occur following sumatriptan administration, prior to the subsequent onset of headache relief.
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Randomized Controlled Trial Clinical Trial
Modulation of thermal pain-related brain activity with virtual reality: evidence from fMRI.
This study investigated the neural correlates of virtual reality analgesia. Virtual reality significantly reduced subjective pain ratings (i.e. analgesia). ⋯ As predicted, virtual reality significantly reduced pain-related brain activity in all five regions of interest; the anterior cingulate cortex, primary and secondary somatosensory cortex, insula, and thalamus (p<0.002, corrected). Results showed direct modulation of human brain pain responses by virtual reality distraction.
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In avulsion injury of the dorsal root, regenerating axons cannot extend through the entry zone, i.e. the transition zone between peripheral and central nervous systems, due to the discontinuity between Schwann cells and astrocytes. We infused neural stem cells through the 4th ventricle in an attempt to enhance axonal growth in injured dorsal roots. Infused stem cells were attached to, and integrated into, the lesion of the root and became associated with axons in the same manner as Schwann cells or perineurial sheath cells in the peripheral nerve, and as astrocytes in the central nerve area. These findings suggest that neural stem cells integrated by infusion through CSF might have a beneficial effect on nerve regeneration by inducing a continuity of Schwann cells and astrocytes at the transition zone.