We used the tail-flick response of rats to study the role of opioid receptors in illness-induced hyperalgesia. An intraperitoneal injection of lithium chloride (LiCl) produced hyperalgesia that was blocked in a dose-dependent manner by subcutaneous injection of the opioid antagonist naloxone. Neither hyperalgesia nor its blockade by naloxone were due to variations in tail-skin temperature induc...

There is evidence that exteroceptive cues associated with drug administration elicit conditional compensatory responding (e.g., hyperalgesia in organisms with a history of morphine administration). Recently it has become apparent that, within each administration, interoceptive early-drug onset cues (DOCs) may become associated with the later, larger drug effect (intraadministration associations...

or more than 25 years, investigators from APL and the Johns Hopkins School of Medicine have collaborated on research aimed at understanding the neural mechanisms of pain sensation. This research is based on correlating results from studies of pain sensations in humans with results from studies of neural activity in anesthetized animals. One aspect of pain that has clinical importance is hyperal...

Diabetic Neuropathy (DN) is one of the prevailing micro vascular complications diabetes which can be characterized by neuropathic pain. Streptozotocin (STZ) induced in rat has been increasingly used as a model painful diabetic neuropathy. STZ injection leads to neurotoxicity peripheral nerves that development Peripheral model. The present study was aimed at exploring protective role Tinospora c...

PAIN after surgery continues to be a major management challenge in clinical practice. In a recent meta-analysis covering some 20,000 patients and 800 publications, Dolin et al. concluded that 41% of all surgical patients still experience moderate to severe acute postoperative pain and that 24% experience inadequate pain relief. Unfortunately, acute postoperative pain control seems not to have s...

The report “Two Types of C Nociceptor in Human Skin and Their Behavior in Areas of Capsaicin-Induced Secondary Hyperalgesia” by Serra et al. (this issue, p. 2770–2781) documents, for the first time, the activation and sensitization of a special class of unmyelinated sensory primary afferent fiber (C-mechanically insensitive or CMi) by capsaicin injected a considerable distance (1–5 cm) from the...

Acute postoperative pain in patients with opioid tolerance creates a significant management challenge for anesthesiologists and pain medicine physicians. A multimodal approach is key; however other factors can complicate management such as opioid induced hyperalgesia. We present the case of a patient on large amounts of intrathecal opioids for chronic pain syndrome with opioid induced hyperalge...

BACKGROUND In addition to caudal subnucleus caudalis (Vc) of the spinal trigeminal complex, recent studies indicate that the subnuclei interpolaris/caudalis (Vi/Vc) transition zone plays a unique role in processing deep orofacial nociceptive input. Studies also suggest that glia and inflammatory cytokines contribute to the development of persistent pain. By systematically comparing the effects ...