Browsing by Author "Yen, Chen-Tung"

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Acid-induced hyperalgesia and anxio-depressive comorbidity in rats
(2014-05-28)
Liu, Yu-Ting
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Shao, Yen-Wen
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Yen, Chen-Tung
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Shaw, Fu-Zen
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生醫電子轉譯研究中心
Fibromyalgia is a prevalent disorder characterized by chronic widespread pain (CWP) and complex comorbid symptoms. A CWP model is developed through repeated unilateral intramuscular injections of acid saline resulting in bilateral mechanical hyperalgesia in rats. The present study aims to evaluate whether both anxious and depressive comorbidities exist in this acid-induced pain model, similarly to patients with CWP syndromes. The anxiety-like behaviors were evaluated using the open field and elevated plus maze tests, and depression-like behaviors were measured by the forced swimming, sucrose consumption, and sucrose preference tests. The pain group receiving acidic saline displayed significantly lower paw withdrawal thresholds for 4 weeks than animals in the vehicle group after repetitive intramuscular injections. The pain group showed a significantly shorter duration of exploring the central zone of the open field and the open arms of the elevated plus maze compared to the vehicle group. The pain group had a significantly lower preference for and consumption of the hedonic sucrose. Moreover, rats with chronic pain showed significantly longer immobility than the vehicle group in the forced swimming test. The results indicate that psychiatric behaviors are exacerbated in the CWP model. This study provides evidence for the validity of the acid-induced pain model analogous to patients with CWP syndromes. (C) 2014 Published by Elsevier Inc.
Differential Expression of Phosphorylated ERK and c-Fos of Limbic Cortices Activities in Response to Tactile Allodynia of Neuropathic Rats
(2018-08-31)
Lin, Hsiao-Chun
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Yen, Chen-Tung
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交大名義發表
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生醫電子轉譯研究中心
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National Chiao Tung University
Neuropathic pain is due to lesion or dysfunction of the somatosensory system. Treating patients with neuropathic pain is difficult because the underlying mechanisms are understood limitedly, especially at the supraspinal level. In this study, we used two kinds of molecular markers to investigate the neuronal activity changes in the anterior cingulate cortex (ACC), insular cortex (IC), and medial prefrontal cortex (mPFC) of the neuropathic rats under tactile allodynia. We used spared nerve injury (SNI) of the sciatic nerve as the neuropathic pain model. Two weeks after SNI surgery, we applied repetitive allodynic stimulation to the conscious rats. After stimulation, the rats were sacrificed, and the immunohistochemistry of phosphorylated extracellular signal-regulated kinase (pERK) and c-Fos was performed. Quantification of immunoreactive cells was carried out by stereological method. For pERK study, the expression of pERK was significantly increased in the mPFC and IC of the SNI rats. For c-Fos study, only mPFC had elevated expression of c-Fos in the SNI rats. The analgesic, gabapentin, reversed the mechanical hyper-sensitivity and the augmented expression of limbic pERK and c-Fos in the SNI rats. Immunofluorescent staining revealed the expression of pERK or c-Fos was restricted to neurons, not glia cells. Our results demonstrated that tactile allodynia represented differential expression of pERK and c-Fos in the limbic cortices of the neuropathic rats.