Neuroscience letters
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Neuroscience letters · Apr 2010
PER2 rhythms in the amygdala and bed nucleus of the stria terminalis of the diurnal grass rat (Arvicanthis niloticus).
The suprachiasmatic nucleus (SCN) of the hypothalamus is the central pacemaker that controls circadian rhythms in mammals. In diurnal grass rats (Arvicanthis niloticus), many functional aspects of the SCN are similar to those of nocturnal rodents, making it likely that the difference in the circadian system of diurnal and nocturnal animals lies downstream from the SCN. Rhythms in clock genes expression occur in several brain regions outside the SCN that may function as extra-SCN oscillators. ⋯ In the BLA, PER2 expression was relatively low for most of the 24-h cycle, but showed an acute elevation late in the light period (ZT10). This pattern is also different from that of nocturnal rodents that show elevated PER2 expression in the mid to late night and into the early day. These results are consistent with the hypothesis that diurnal behavior is associated with a phase change between the SCN and extra-SCN oscillators.
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Neuroscience letters · Apr 2010
Behavioral evidence of thermal hyperalgesia and mechanical allodynia induced by intradermal cinnamaldehyde in rats.
TRPA1 agonists cinnamaldehyde (CA) and mustard oil (allyl isothiocyanate=AITC) induce heat hyperalgesia and mechanical allodynia in human skin, and sensitize responses of spinal and trigeminal dorsal horn neurons to noxious skin heating in rats. TRPA1 is also implicated in cold nociception. We presently used behavioral methods to investigate if CA affects sensitivity to thermal and mechanical stimuli in rats. ⋯ CA significantly reduced mechanical withdrawal thresholds of the injected paw that peaked sooner (3 min) and was more profound (44.4% of baseline), with no effect contralaterally. Bilateral intraplantar injections of CA resulted in a significant cold hyperalgesia (cold plate test) and a weak enhancement of innocuous cold avoidance (thermal preference test). The data are consistent with roles for TRPA1 in thermal (hot and cold) hyperalgesia and mechanical allodynia.
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Neuroscience letters · Apr 2010
Catechol-O-methyltransferase (COMT) inhibition reduces spinal nociceptive activity.
Several variants of the catechol-O-methyltransferase (COMT) gene have recently been linked to pain sensitivity. In the present study, electrophysiological field potential recordings from the dorsal horn in rats were used to examine the spinal effect of reduced COMT activity. ⋯ HFS+OR 486). Our findings suggest that low COMT activity may have an antinociceptive effect in the spinal cord.
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Neuroscience letters · Apr 2010
Functional endothelial progenitor cells derived from adipose tissue show beneficial effect on cell therapy of traumatic brain injury.
Endothelial progenitor cells (EPCs) are responsible for postnatal vasculogenesis in physiological and pathological neovascularization. Adipose tissue (AT) is an abundant source of mesenchymal stem cells (MSCs), which have multipotent differentiation ability. We successfully derived EPCs from AT, which maintained a strong proliferative capacity and demonstrated the characteristic endothelial function of uptaking of acetylated low-density lipoprotein. ⋯ Transplanted EPCs participated in the neovascularization of injured brain. Improving functional recovery, reducement of deficiency volume of brain, host astrogliosis and inflammation were found. These results suggest that adult AT derived stem cells can be induced to functional EPCs and have beneficial effect on cell therapy.