Brain research
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Chemotherapy-induced pain is the most common treatment-limiting complication encountered by cancer patients receiving taxane-, vinca alkaloid- or platin-based chemotherapy. Several lines of evidence indicate that activation of pro-inflammatory cascades involving the release of cytokines including tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1beta) and interleukin-6 (IL-6) as well as various growth factors are key events in the pathogenesis of many types of nerve-injury related pain. Similar mechanisms might also be involved in the etiology of chemotherapy-induced pain. ⋯ These compounds were evaluated here for effects in preventing the development of taxol-induced mechanical and thermal hyperalgesia in rats. Thalidomide (50.0 mg/kg) reduced taxol-induced mechanical allodynia and hyperalgesia whereas minocycline (20.0 mg/kg) reduced taxol-induced mechanical hyperalgesia and allodynia as well as taxol-induced thermal hyperalgesia. These results suggest that immunomodulatory agents may provide a treatment option for the protection or reversal of chemotherapy-related pain.
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The purpose of this project was to explore the role of the medial thalamus (MT), including the medial dorsal thalamus (MD) and associated midline nuclei in pain processing. Experiment 1 explored the role of electrolytic lesions to the MT in the formalin test. It was hypothesized that animals with electrolytic lesions to the MT would have attenuated paw licking behavior during the second phase of the formalin tests as compared to sham lesion controls. ⋯ No differences in mechanical paw withdrawal thresholds and in escape/avoidance behavior were detected as compared to the sham lesion group. These results indicate a limited role for the medial thalamic nuclei in coding for pain intensity and the affective dimension of pain. Additional research is needed to explore the role of individual medial nuclei in pain processing.
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The bed nucleus of the stria terminalis (BNST) in the forebrain shows sexual dimorphism in its neuroanatomical connectivity and neurochemical characteristics. The structure is involved in many behavioral and motivational phenomena particularly related to coping with stress. ⋯ The present study extended the findings to female rats demonstrating that bilateral electrolytic lesions of the BNST increased immobility and decreased climbing compared to sham-operated controls, but failed to affect performance in the water maze. Additionally, lesions did not alter behavior in the open field and the elevated plus-maze tests suggesting not only that the modulation of depression by BNST lesions is specific, but also providing support for the view that the BNST may not necessarily be critically involved in anxiety.