title: Chronic treadmill exercise in rats delicately alters the Purkinje cell structure to improve motor performance and toxin resistance in the cerebellum.
abstract: Although exercise usually improves motor performance, the underlying cellular changes in the cerebellum remain to be elucidated. This study aimed to investigate whether and how chronic treadmill exercise in young rats induced Purkinje cell changes to improve motor performance and rendered the cerebellum less vulnerable to toxin insults. After 1-wk familiarization of treadmill running, 6-wk-old male Wistar rats were divided into exercise and sedentary groups. The exercise group was then subjected to 8 wk of exercise training at moderate intensity. The rotarod test was carried out to evaluate motor performance. Purkinje cells in cerebellar slices were visualized by lucifer yellow labeling in single neurons and by calbindin immunostaining in groups of neurons. Compared with sedentary control rats, exercised rats not only performed better in the rotarod task, but also showed finer Purkinje cell structure (higher dendritic volume and spine density with the same dendritic field). The exercise-improved cerebellar functions were further evaluated by monitoring the long-lasting effects of intraventricular application of OX7-saporin. In the sedentary group, OX7-saporin treatment retarded the rotarod performance and induced ∼60% Purkinje cell loss in 3 wk. As a comparison, the exercise group showed much milder injuries in the cerebellum by the same toxin treatment. In conclusion, exercise training in young rats increased the dendritic density of Purkinje cells, which might play an important role in improving the motor performance. Furthermore, as Purkinje cells in the exercise group were relatively toxin resistant, the exercised rats showed good motor performance, even under toxin-treated conditions.
authors: Department of Physiology, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors: Tung-Yi
authors: TY
authors: Huang
authors: Lung-Sheng
authors: LS
authors: Lin
authors: Keng-Chi
authors: KC
authors: Cho
authors: Shean-Jen
authors: SJ
authors: Chen
authors: Yu-Min
authors: YM
authors: Kuo
authors: Lung
authors: L
authors: Yu
authors: Fong-Sen
authors: FS
authors: Wu
authors: Jih-Ing
authors: JI
authors: Chuang
authors: Hsiun-Ing
authors: HI
authors: Chen
authors: Chauying J
authors: CJ
authors: Jen
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000633:toxicity*; D015415:Biomarkers / Q000378:metabolism; D064026:Calbindins; D048430:Cell Shape; D005455:Fluorescent Antibody Technique; D018796:Immunoconjugates / Q000008:administration & dosage / Q000633:toxicity*; D000922:Immunotoxins / Q000008:administration & dosage / Q000633:toxicity*; D007276:Injections, Intraventricular; D008297:Male; D008856:Microscopy, Fluorescence; D009043:Motor Activity / Q000187:drug effects; D020258:Neurotoxicity Syndromes / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D005082:Physical Exertion; D011689:Purkinje Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D054789:Ribosome Inactivating Proteins, Type 1 / Q000008:administration & dosage / Q000633:toxicity*; D012420:Running; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D000076985:Saporins; D057185:Sedentary Behavior; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D064026:Calbindins; D018796:Immunoconjugates; D000922:Immunotoxins; C085346:OX7-saporin; D054789:Ribosome Inactivating Proteins, Type 1; D064030:S100 Calcium Binding Protein G; D000076985:Saporins