Caloric vestibular stimulation modulates nociceptive evoked potentials

Vestibular stimulation has been reported to alleviate central pain. Clinical and physiological studies confirm pervasive interactions between vestibular signals and somatosensory circuits, including nociception. However, the neural mechanisms underlying vestibular-induced analgesia remain unclear, and previous clinical studies cannot rule out explanations based on alternative, non-specific effects such as distraction or placebo. To investigate how vestibular inputs influence nociception, we combined caloric vestibular stimulation (CVS) with psychophysical and electrocortical responses elicited by nociceptive-specific laser stimulation in humans (laser-evoked potentials, LEPs). Cold water CVS applied to the left ear resulted in significantly lower subjective pain intensity for experimental laser pain to the left hand immediately after CVS, relative both to before CVS and to 1 h after CVS. This transient reduction in pain perception was associated with reduced amplitude of all LEP components, including the early N1 wave reflecting the first arrival of nociceptive input to primary somatosensory cortex. We conclude that cold left ear CVS elicits a modulation of both nociceptive processing and pain perception. The analgesic effect induced by CVS could be mediated either by subcortical gating of the ascending nociceptive input, or by direct modulation of the primary somatosensory cortex

Polymer–Ceramic Nanohybrid Materials

This review is dedicated to nanohybrid materials consisting of a polymer-based matrix and a disperse nanoscaled ceramic phase. Different preparation techniques for the synthesis of polymer–ceramic nanohybrid materials will be presented, such as blending techniques, sol–gel processing, in-situ polymerization, and self-assembly methods. Selected structural and functional properties of polymer–ceramic nanohybrid materials will be highlighted and discussed within the context of their dependence on parameters such as the homogeneity of the dispersion of the ceramic throughout the polymer matrix, the particle size of the ceramic phase, and the polymer–ceramic interface. Moreover, some advanced applications of polymer–ceramic nanohybrid materials will be addressed and compared with their polymeric counterparts