Chronic pain is a major public health problem with limited treatment options. Opioids remain a routine treatment for chronic pain, but extended exposure to opioid therapy can produce opioid tolerance and hyperalgesia. Although the mechanisms underlying chronic pain, opioid-induced tolerance, and opioid-induced hyperalgesia remain to be uncovered, mammalian target of rapamycin (mTOR) is involved...

Orexin is produced exclusively in the lateral hypothalamus, where it is known to be involved in pain modulation through brain stem. Due to the important role of this peptide in functions such as eating, sleeping and awaking, addiction, it attracted the attention of researchers in medical sciences specially neuroscientists. These hypothalamic peptides play a critical role in arousal in s...

Despite the discovery of ion channels that are activated by protons, we still know relatively little about the signaling of acid pain. We used a novel technique, iontophoresis of protons, to investigate acid-induced pain in human volunteers. We found that transdermal iontophoresis of protons consistently caused moderate pain that was dose-dependent. A marked desensitization occurred with persis...

introduction: the role of midbrain reticular formation, which includes the nucleus cuneiformis (ncf), as a crucial antinociceptive region in descending pain modulation has long been investigated. in this study, we tried to highlight the role of ncf in morphine-induced antinociception in formalin-induced pain model in rats. methods: a total of 201 male wistar rats weighing 260-310 g were used in...

OBJECTIVE To examine the effects of experimentally induced pain and fear of pain on trunk coordination and erector spinae EMG activity during gait. DESIGN In 12 healthy subjects, hypertonic saline (acute pain) and isotonic saline (fear of pain) were injected into erector spinae muscle, and unpredictable electric shocks (fear of impending pain) were presented during treadmill walking at differ...

Objective(s): There are many reports about the role of rostral ventromedial medulla (RVM) in modulating stress-induced analgesia (SIA). In the previous study we demonstrated that temporal inactivation of RVM by lidocaine potentiated stress-induced analgesia. In this study, we investigated the effect of permanent lesion of the RVM on SIA by using formalin test as a model of acute inflammatory pa...

objective(s): intracerebroventricular injection of orexin-a (hypocretin-1) antagonist has been shown to inhibit stress-induced analgesia. however the locations of central sites that may mediate these effects have not been totally demonstrated. this study was performed to investigate the role of rostral ventromedial medulla (rvm) orexin receptor 1 in stress-induced analgesia (sia). materials and...

Chronic musculoskeletal pain is a significant health problem and is associated with increases in pain during acute physical activity. Regular physical activity is protective against many chronic diseases; however, it is unknown if it plays a role in development of chronic pain. The current study induced physical activity by placing running wheels in home cages of mice for 5 days or 8 wk and com...