Neuroreport
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Amyotrophic lateral sclerosis is a devastating motor neuron disorder. Traditionally regarded as a 'neuron only' disease, recent evidence suggested that other cells contribute critically to the pathogenesis. This review provides a short synopsis of the role neuroinflammation and microglial cells play in the disease and its animal models. A better understanding of neuroinflammation in motor neuron degeneration and amyotrophic lateral sclerosis disease progression promises to improve the rational design of greatly needed therapies.
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This review highlights recent developments in research on human cortical oscillations in the gamma-band range (30-100 Hz). Electroencephalography has demonstrated a role of these signals for cognitive functions including visual perception, attention, learning and memory. ⋯ Additional gamma-band activity has been found over the frontal cortex during top-down tasks. Oscillatory activity in the gamma range may serve to assess the temporal dynamics of cortical networks and their interactions.
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Comparative Study Clinical Trial
Functional connectivity changes with concentration of sevoflurane anesthesia.
Low-frequency oscillations (<0.08 Hz) have been detected in functional magnetic resonance imaging studies, and appear to be synchronized between functionally related areas. The effect of anesthetic agents on cortical activity is not completely characterized. ⋯ Across all volunteers, the number of significant voxels (p<2.5 x 10) in the functional connectivity maps was reduced by 78% for light anesthesia and by 98% for deep anesthesia, compared with the awake state. Additionally, significant correlations in the connectivity maps were bilateral in the awake state but unilateral in the light anesthesia state.
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Comparative Study
Potentiation of spinal N-methyl-D-aspartate-mediated nociceptive transmission by cocaine-regulated and amphetamine-regulated transcript peptide in rats.
The present study examined the effects of cocaine-regulated and amphetamine-regulated transcript peptide (CARTp) fragment 55-102, on N-methyl-D-aspartate (NMDA)-mediated nociceptive transmission in vivo and in vitro. In-vivo experiments were conducted in Sprague-Dawley rats to evaluate the effects of CARTp on thermal hyperalgesia induced by NMDA or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Intrathecal NMDA (1, 2, 4 nmol) or AMPA (0.5, 1, 2 nmol) dose-dependently decreased the tail-flick latency. ⋯ The in-vitro effects of CARTp on NMDA-induced or AMPA-induced depolarizations in substantia gelatinosa neurons were studied in rat spinal cord slices. CARTp (100, 300 nM), which caused no significant change of membrane potentials, increased the amplitude of NMDA-induced depolarizations in substantia gelatinosa neurons with little effect on AMPA-induced depolarizations. The present study demonstrates that exogenously applied CARTp selectively facilitates NMDA receptor-mediated nociceptive transmission.
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Orexins are synthesized by neurons in the hypothalamus and contribute to multiple physiological functions. Orexin fibers innervate many regions of the CNS, which include areas involved in descending control of pain. We examined the role orexins may play in endogenous modulation of pain transmission using prepro-orexin (precursor of orexin A and B) knockout mice. ⋯ Knockout mice presented greater degree of hyperalgesia induced by peripheral inflammation and less stress-induced analgesia than wild type mice. Double staining of orexin and c-Fos in wild type mice revealed activation of orexin neurons under both conditions. These results suggest that persistent pain and stress activate orexin neurons, which act to inhibit pain transmission.