To address Gabr alpha 6 role in myofascial pain we hypothesized that Gabr alpha 6 has an inhibitory role in myofascial nociceptive responses similar to inflammatory TMJ arthritis. To test this hypothesis check details a, myofascial nociceptive response was induced by placing a ligature bilaterally on the tendon attachment of the anterior superficial part of a male rat’s masseter muscle. Four days after ligature placement Gabr alpha 6 expression was reduced by infusing the trigeminal ganglia (TG) with small interfering RNA (siRNA) having homology to either the Gabr alpha 6 gene (Gabr alpha 6 siRNA) or no known gene (control siRNA). After
siRNA infusion nociceptive behavioral responses were measured, i.e., feeding behavior and head withdrawal after pressing upon the region above the ligature with von Frey filaments. Neuronal activity in the TG and trigeminal nucleus caudalis and upper cervical region (Vc-C-1) was measured by quantitating the amount of phosphorylated LCZ696 cost extracellular signal-regulated kinase (p-ERK). Total Gabr alpha 6 and GABA(A) receptor contents in the TG and Vc-C-1 were determined.
Gabr alpha 6 siRNA infusion reduced Gabr alpha 6 and GABA(A) receptor expression and significantly increased the nociceptive response in both nociceptive assays. Gabr alpha 6 siRNA infusion also significantly increased TG p-ERK expression of the ligated rats. From these results we conclude GABA(A) receptors selleck products consisting of the Gabr alpha 6 subunit inhibit TG nociceptive sensory afferents in the trigeminal pathway and have an important role in the regulation of myofascial nociception. (C) 2013 IBRO. Published by Elsevier Ltd.
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“Pinnipeds have to cope with the thermoregulatory demands of their amphibious lifestyle. As they are effectively insulated against heat loss in water by their blubber, they have to bypass the blubber for heat dissipation while staying ashore. In previous studies thermal windows on the body of captive phocid seals have been described as areas of heat dissipation in air. In this study we used infrared thermography (IRT) to examine thermal windows in seals hauling out as well as in training situations, where the first refers to a voluntary and the latter to an induced stay on shore. Furthermore we provide an IRT-based estimate of heat loss through thermal windows in pinnipeds. Hauling out seals developed thermal windows within a few minutes irrespective of environmental conditions. By contrast, seals staying on shore on a trainer’s command did not develop thermal windows at all. The calculation of heat loss through thermal windows resulted in considerable values in air, but above all in water, which is energetically disadvantageous as it takes up to four minutes to close thermal windows in water. (C) 2012 Elsevier Ltd. All rights reserved.