The Role of Attractin in Neurodegeneration Caused by Oxidative Stress

Oxidative stress is linked to dopaminergic (DA) neurodegeneration in Parkinson’s disease. Our laboratory reported slowly progressive DA neurodegeneration in the zitter (zi) rat, which is Attractin (Atrn) deficient. However, little is known about the function of Atrn in the central nervous system (CNS). Thus, we investigated whether DA neurodegeneration in the zi rat was induced by oxidative stress, and how Atrn affects oxidative stress. First, we summarize our previous in vivo data, which revealed suppression of DA neurodegeneration using antioxidants (vitamin E and melatonin) in zi rats. Second, our current ex vivo and in vitro studies are introduced. Using primary neuronal cultures of zi mesencephalon as a model of Atrn-deficient neurons or Atrn-GFP-overexpressing HEK293 cells, accumulation of reactive oxygen species (ROS) in mitochondria and cell viability was examined under oxidative stress. Atrn-deficient neurons accumulated excess ROS in mitochondria, resulting in neurodegeneration, whereas Atrn-overexpressing cells showed suppression of ROS accumulation under oxidative stress. These results showed that Atrn plays a suppressive role against ROS and that the loss of Atrn function induced excess ROS accumulation and led to DA neurodegeneration. This is the first report to show that Atrn directly modulates mitochondrial ROS accumulation in the CNS

第2学年「組織学総論」・「基礎神経科学」の教育効果の検討 ─中間試験導入と事前・事後学習課題の提示─

獨協医科大学医学部では平成27年度より，発展的に自己学習習慣を身につけさせるため，講義時間・カリキュラムの変更を行っている.この効果を検討するため，変更前の2 年間 （平成25 年度および平成26 年度） と変更後の2年間 （平成27年度および平成28年度） の「組織学総論」および「基礎神経科学」の試験結果を比較し解析した．対象は，平成25年度138 名，平成26年度129 名，平成27年度133 名，平成28年度121 名の2年生である．事後学習課題の提出・評価，中間試験成績，学期末試験成績の結果とそれぞれの関連を解析した．特に中間試験を形成的評価と位置づけ，総合的評価としての学期末試験に及ぼす影響について検討した．形成的評価として中間試験を取り入れることにより，学生の学習方法の改善と学習意欲を促し学期末試験結果が向上した．事前・事後学習課題の提示は，知識の定着に有効であった．また，課題の評価と成績は関連しなかったが，未提出や期限切れ提出を繰り返す学生が成績不良となることが多く，事前・事後学習課題の提示は，早期指導介入のスクリーニングとして有効であると考えられた．Dokkyo Medical University made lecture time and curriculum changes, in effect since the 2015-16 school year, to help students learn self-study habits for their development. To examine the effectiveness of these changes, test results of “Introduction to Histology” and “Basic　Neuroscience” for the two years after the changes （i.e., the 2015-16 and 2016-17 school years）were compared to those of the two years before the changes （2013-14 and 2014-15） and analysis was performed. The comparison focused on second-year students, including 138 in 2013-14, 129 in 2014-15, 133 in 2015-16, and 121 in 2016-17. The correlations among post-class homework submission and scores, midterm test grades, and end-of-term test grades were analyzed. In particular, midterm tests （objective tests）were treated as formative scores and their effect on end-of-term tests（general scores）was examined. By introducing midterm tests（objective tests）as formative scores, the courses helped students/learners to improve their study methods, motivated them to study, and resulted in higher grades during end-of-term tests. Assigning preclass and post-class homework was an effective way to firmly establish knowledge. Additionally, though there was no correlation between homework scores and grades, students who repeatedly failed to submit homework or submitted it late often got poor grades, meaning that homework evaluation seems to be effective screening for earlyguidance and intervention

Parvalbumin-positive Neurons in the Mouse A8 Region were Lesser than those in the Rat

Dopaminergic neurons play crucial roles in various physiological functions, such as reward, goal-directed behavior, memory formation, and pain sensation. One of the main dopaminergic cell groups in the brain is located in the retrorubral field (RRF, A8 region). A recent electrophysiological study using rats revealed that distinct neurons within the A8 region respond to the different degrees of the threat and aversive stimuli, and that the RRF is the origin of neural signals for threat and aversive outcomes. However, neurochemical characterization of the constituents of the A8 region is not enough. The aim of this study is to determine the neurochemical characteristics of these A8 neurons. To examine the neurochemical cellular organization of the A8 region, we performed immunohistochemistry for two GABAergic neuronal markers, parvalbumin (PV) and neuronal nitric oxide synthase (nNOS), in relation to tyrosine hydroxylase, a marker of dopaminergic neurons. We observed that the number of PV-positive neurons in the mouse A8 region was lesser than in rats. Moreover, nNOS-positive neurons were not detected within the A8 region in either species. These results indicate that the neurochemical organization of the A8 region was distinct between mice and rats. In addition, the cellular composition of the A8 dopaminergic cell group was distinct from other dopaminergic cell groups, such as the A9 and A10 region, in both mice and rats. Understanding these differences among species and cell groups is worth noting for translating the results obtained with distinct animal models into a clinical application