Mechanical allodynia, the perception of innocuous tactile stimulation as painful, is a severe symptom of chronic pain often produced by damage to peripheral nerves. Allodynia affects millions of people and remains highly resistant to classic analgesics and therapies. Neural mechanisms for the development and maintenance of allodynia have been investigated in the spinal cord, brainstem, thalamus...

Chemotherapy-induced peripheral neuropathy is a major dose-limiting side effect of commonly used chemotherapeutic agents. However, there are no effective strategies to treat the neuropathy. We examined whether Goshajinkigan, a herbal medicine, would prevent paclitaxel-induced allodynia without affecting the anticancer action in mice. Murine breast cancer 4T1 cells were inoculated into the mamma...

In this study, we examined whether several types of non-opioid agents would inhibit the pain-related responses of melanoma-bearing mice. Orthotopic inoculation with melanoma into the hind paw induced marked tactile allodynia and mechanical hyperalgesia. A peroral injection (p.o.) of gabapentin (100-300 mg/kg) inhibited the allodynia and hyperalgesia, without effects on gross behaviors. An intra...

Recently, we showed that most migraine patients exhibit cutaneous allodynia inside and outside their pain-referred areas when examined during a fully developed migraine attack. In this report, we studied the way in which cutaneous allodynia develops by measuring the pain thresholds in the head and forearms bilaterally at several time points during a migraine attack in a 42-year-old male. Prior ...

Allodynia is defined as the experience of pain due to nonpainful stimuli, and occurs in several clinical contexts, including primary headaches. Cluster headache is a primary cephalalgia which is more common in males, characterized by excruciating pain, and autonomic trigeminal dysfunction. The prevalence of allodynia in cluster headache patients is a relevant matter with few studies devoted to....

Long-lasting neuroplastic changes induced by transient decrease in G protein-coupled receptor kinase 2 (GRK2) in nociceptors enhances and prolongs inflammatory hyperalgesia. Here, we investigated the effects of paroxetine (a selective serotonin reuptake inhibitor and GRK2 inhibitor) on GRK2 expression in superior cervical ganglion (SCG) in a rat model of complex regional pain syndrome type I (C...

Serotonin in the spinal cord acutely modulates nociceptive transmission and motor reflexes and may also assist functional restoration after spinal cord injury (SCI). It is released there mainly by descending axons of the medulla's nucleus raphe magnus (NRM). We examined whether mechanical allodynia (cutaneous hypersensitivity) after incomplete SCI is sustainably reversed by prolonged, intermitt...

Ciguatera, the most common form of nonbacterial ichthyosarcotoxism, is caused by consumption of fish that have bioaccumulated the polyether sodium channel activator ciguatoxin. The neurological symptoms of ciguatera include distressing, often persistent sensory disturbances such as paraesthesias and the pathognomonic symptom of cold allodynia. We show that intracutaneous administration of cigua...

Tetanic stimulation of the sciatic nerve (TSS) induces sciatic nerve injury and long-lasting pain hypersensitivity in rats, and spinal glial activation and proinflammatory cytokines releases are involved. In the present study, we showed that spinal interleukin (IL)-23 and its receptor, IL-23R, are crucial for the development of mechanical allodynia after TSS. In the spinal dorsal horn, both IL-...

Oxaliplatin, a chemotherapy drug, induces acute peripheral neuropathy characterized by cold allodynia, spinal glial activation and increased levels of pro-inflammatory cytokines. Herein, we determined whether Cinnamomi Cortex (C. Cortex), a widely used medicinal herb in East Asia for cold-related diseases, could attenuate oxaliplatin-induced cold allodynia in rats and the mechanisms involved. A...