Physical disuse contributes to widespread chronic mechanical hyperalgesia, tactile allodynia, and cold allodynia through neurogenic inflammation and spino-parabrachio-amygdaloid pathway activation
Autor: | Takashi Nakano, Makoto Tsuda, Munekazu Naito, Koji Osuka, Yusuke Ohmichi, Mika Ohmichi, Dominika Kanikowska, Ryoichi Tashima, Hiromu Yawo, Kaori Fukushige, Yugo Fukazawa |
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Rok vydání: | 2020 |
Předmět: |
medicine.medical_specialty
Vascular permeability Optogenetics Rats Sprague-Dawley 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine 030202 anesthesiology Internal medicine Animals Medicine Pain Measurement Muscle contracture Evans Blue Neurogenic inflammation business.industry Chronic pain medicine.disease Rats Anesthesiology and Pain Medicine Allodynia Endocrinology Nociception Neurology chemistry Hyperalgesia Neurology (clinical) Chronic Pain Neurogenic Inflammation medicine.symptom business 030217 neurology & neurosurgery |
Zdroj: | Pain. 161:1808-1823 |
ISSN: | 1872-6623 0304-3959 |
DOI: | 10.1097/j.pain.0000000000001867 |
Popis: | Physical disuse could lead to a state of chronic pain typified by complex regional pain syndrome type I due to fear of pain through movement (kinesiophobia) or inappropriate resting procedures. However, the mechanisms by which physical disuse is associated with acute/chronic pain and other pathological signs remain unresolved. We have previously reported that inflammatory signs, contractures, disuse muscle atrophy, spontaneous pain-like behaviors, and chronic widespread mechanical hyperalgesia based on central plasticity occurred after 2-weeks of cast immobilization in chronic post-cast pain (CPCP) rat model. In the present study, we also demonstrated dystrophy-like changes, both peripheral nociceptive signals and activation of the central pain pathway in CPCP rats. This was done by the following methods: (1) vascular permeability (Evans blue dye) and inflammatory- and oxidative stress-related messenger RNA (mRNA) changes (real-time quantitative polymerase chain reaction); (2) immunofluorescence of pERK and/or c-Fos expression in the spino-parabrachio-amygdaloid pathway; and (3) blockade of nociceptive-related signals using sciatic nerve block (SNB). Furthermore, we demonstrated tactile allodynia using an optogenetic method in a transgenic rat line (W-TChR2V4), cold allodynia using the acetone test, and activation of dorsal horn neurons in the chronic phase associated with chronic mechanical hyperalgesia using c-Fos immunofluorescence. In addition, we showed that nociceptive signals in the acute phase are involved in chronic pathological pain-like behaviors by studying the effects of SNB. Thus, we conclude that physical disuse contributes to dystrophy-like changes, spontaneous pain-like behavior, and chronic widespread pathological pain-like behaviors in CPCP rats after 2 weeks of cast immobilization. |
Databáze: | OpenAIRE |
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