Neuroscience letters
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Neuroscience letters · Apr 2014
Agomelatine restores a physiological response to stress in the aged rat.
Short duration immobilization stress (IS) in younger rats is followed by a sleep rebound involving slow wave sleep (SWS) and, more particularly, rapid eye movement (REM) sleep. This rebound, expressing the ability of the brain to confront a stress challenge, is now accepted as a marker of the homeostasis. In older rats (24-25 months), however, an IS of 1h is not followed by a sleep rebound. ⋯ Older rats pretreated with agomelatine for 3 days showed a reversal of the deficit observed in the beta-1, but not in the delta, EEG power band. Application of an IS to older rats after agomelatine pretreatment resulted in a REM sleep rebound in response to stress. These findings indicate that agomelatine, by improving beta-1 EEG power band and by inducing stress-related sleep rebound in older animals, contributes to the homeostasis maintenance.
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Neuroscience letters · Apr 2014
Resveratrol attenuates morphine antinociceptive tolerance via SIRT1 regulation in the rat spinal cord.
In recent years, researchers have begun to pay more attention to the role of Sirtuin 1 (SIRT1, a class III histone deacetylase) in pain. However, little research has been conducted examining the involvement of SIRT1 in chronic morphine tolerance. The aim of this study was to investigate the role of spinal SIRT1 and acetyl-histone H3(Ac-H3) in chronic morphine tolerance in rats. ⋯ Resveratrol treatment from day 7 to 13 increased SIRT1 expression, suppressed global Ac-H3 expression compared to the morphine tolerance (MT) group, and significantly reversed morphine antinociceptive tolerance. These results suggest that resveratrol reversed morphine tolerance by upregulating the expression of SIRT1 in the spinal dorsal horn. SIRT1 and global Ac-H3 in the spinal cord may play an important role in the mechanisms of chronic morphine tolerance.
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Neuroscience letters · Apr 2014
Alteration of nerve growth factor in dorsal root ganglia at early time of acute myocardial infarction and the role of spinal nerve afferents.
Nerve growth factor (NGF) plays important roles in transmission of nociception, neural innervation and survival in sympathetic and sensory neurons. Evidence indicates that NGF may sensitize the sensory and sympathetic reaction upon noxious stimulation. Understanding of the alterations of NGF in the sensory neurons during acute myocardial infarction and the underlying mechanism may promote clinical prognosis of the pathology. ⋯ It was found that the immunoreactive material for NGF was significantly increased in the ganglia (P<0.05) at 60min of myocardial infarction, without change in NGF mRNA before and after the time. Blockade of the spinal nerves obviously inhibited the expression of NGF (P<0.05) and the coding mRNA (P<0.01). The results may indicate that the spinal nerve afferents are important in sustaining and up-regulating the expression of NGF in the sensory neurons innervating the heart in acute myocardial infarction.