| Summary: | 碩士 === 國立臺灣師範大學 === 生命科學研究所 === 99 === Spinocerebellar ataxia (SCA) is a progressing neurodegenerative disease. There have been identified 28 different types. The pathological symptom of the SCA17 shows progressive ataxia, dysphagia and dysphonia, tremor, nystagmus, cognitive decline, psychiatric symptoms, dementia. The SCA 17 is caused by the expansion of CAG repeat of TATA-binding protein, which leads to an abnormal expansion of a polyglutamine stretch in the N-terminal of the corresponding protein. These may result in protein aggregation and contribute to cytotoxicity. Dysphagia and Dysphonia might correlate with vocal fold dysfunction. The vocal fold movements are mainly controlled by the recurrent larynageal nerve (RLN) and regulated also by the pons. In clinics, patients with SCA 17 showed pontine atrophy after death autopsy. In this regard, we had observed that there was a reflexively blunt response of the RLN to capsaicin-induced activation of the pulmonary C-fibers in SCA17 transgenic mice of six-month old. The problem is that the six-month old mice might represent old animal model, suggesting that the glottis may have been mulfunctioned. Whether this blunt response of the RLN to capsaicin administration could be observed in the young transgenic mice is remained to be determined. This is very important since it would implicate that the young patients might have also the opportunity of a dysfunctional swallowing and pronunciation. To answer this question, the present study was divided into two parts. First, the RLN activities were evaluated in response to capsaicin-induced activation of the pulmonary C-fibers in three-month young transgenic mice. The results obtained displayed that there was a similar increase in the RLN during apnea induced by capsaicin administration in transgenic young mice compared with that in the control littermate wild type animals. Second, the glottal movement was investigated in response to capsaicin administration in transgenic mice. The results observed showed that the glottal area during apnea and the first respiratory cycle recovery from apnea initiated by capsaicin administration was the same in transgenic mice as those seen in the control littermate wild type animals. These results indicate that the glottal movement of the young SCA17 transgenic mice may have a similar response to capsaicin administration compared with that in control animals. It may also suggest that the regulatory mechanism of the vocal fold movement is probably still normally functioned in young SCA17 mice.
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