ABSTRACT
Histology teaching requires a combination of theory and experiment for a better understanding of microstructure and related functions of body.On the basis of the comparison and summary of the advantages and limitations of traditional light microscopy tissue slices and the emerging digital slicing,we combined them in the teaching of micromorphology experiments to achieve a better teaching results.Each experimental course (about 3 to 4 hours) was divided into four parts:teaching videos,observation of light microscopy tissue slices and digital slicing,discussion on course content and random quizzes.This teaching method contributed to the improvement of the students' interest and motivation in learning,the teachers' teaching efficiency and the overall teaching quality.
ABSTRACT
Objective To detect the expressions of Lingo-1 and myelin associated protein in the white matter and hippocampus of ovariectomized rats after short-term estrogen replacement therapy in order to explore the possible mechanisms for the effects of estrogen on the brain myelin sheaths and cognitive function.Methods 24 middleaged (9-12 months) female Sprague-Dawley (SD) rats were bilaterally ovariectomized (OVX) and randomly divided into vehicle replacement (OVX+Veh) group and estrogen replacement (OVX+E) group.After one month ERT,The spatial learning and memory ability of all rats were assessed with Morris water maze.Then,10 rats were randomly selected from each group.The ultrastucture of myelin sheaths in the cerebral white matter and hippocampus were observed,and the protein expression of MBP and Lingo-1 were investigated with Western blot and immunohistochemical staining.Results The escape latencies of OVX+E rats in navigation test were significantly shorter than that of OVX+Veh rats(P＜0.05).The myelin sheaths in the white matter and hippocampus of OVX+Veh rats showed obviously degeneration.In the OVX+E group,the expression of MBP in the white matter and hippocampus was significantly higher than that of OVX+Veh group(P＜0.05),however,the expression of Lingo-1 was significantly lower than that of OVX +Veh group (P＜ 0.05).Conclusions One-month ERT has significant beneficial effects on the spatial learning capacity and myelin sheaths in the white matter and hippocampus.The protective effects may be related to estrogen-induced downregulation of the Lingo-1 expression in the white matter and hippocampus of rats.
ABSTRACT
Objective To explore the role of white matter injuries in the schizophrenia induced by the NMDA re-ceptor antagonist. Methods Adult male C57BL/6J mice (8 week old) were equally divided into four groups. One group was sub-chronically treated with saline solution, and the other three groups were intraperitoneally treated with MK-801 at dose of 0.025 mg/mL (M1), 0.050 mg/mL (M2) and 0.100 mg/mL (M3) in a volume 10 ml per kilogram body weight. All ani-mals were tested using Morris water maze at the 9th-15th day and using the Hole Board exploration as well as Rota Rod performance tests on the 16th day. The myelin basic protein (MBP) and the ultrastructure of the myelin sheaths in the cor-pus callosum were then examined using immunohistochemical methods, transmission electron microscope technique and stereological methods. Results The repeated sub-chronic MK-801 treatment did not induce impairment of spatial learning and memory in Morris water maze. The MK-801 treatment at 0.25 mg/kg and 1.00 mg/kg but not at 0.50 mg/kg resulted in less exploration to a new environment. The myelin staining with anti-MBP antibody was less intense in all three schizo-phrenic groups when compared to saline control group (P<0.01). Furthermore, MK-801 treatment caused pathological al-terations of the myelin sheaths including segmental demyelination of myelinated fibers and splitting of myelin sheath lamel- lae in schizophrenic groups. The ratio of the injured myelinated nerve fibers in the corpus callosum of MK-801 treated mice [M3 group, (22.42 ± 4.24)%] was significantly higher when compared to the control mice [(3.84 ± 1.35)%,P<0.01)]. Conclusions The present study demonstrated the white matter damages, mainly low MBP expression and segmental demye-lization in the corpus callosum in the mice sub-chronic treated with MK-801, indicating that the white matter changes might be involved in the schizophrenia induced by NMDA antagonist.