Decline of learning and memory in senility and expression of cyclin-dependent kinase-5 in brain development of rats
- VernacularTitle:老年性学习记忆减退与大鼠脑发育过程中周期素依赖性蛋白激酶5的表达
- Author:
Hongli LI
;
Zhong YANG
;
Yu SUN
;
Zegui LI
;
Wenqin CAI
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2005;9(24):247-249
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Cyclin-dependent kinase-5 (CDK-5) is one of the members in cyclin-dependent protein kinase family. The attention has being drawn by researchers on the relationship between the expression and distribution of CDK-5 mRNA and its protein in the brain during brain development and neural degeneration in thought-cognition.OBJECTIVE: To probe into the influence of CDK-5 on neurogeny and neural degeneration during cerebral development.DESIGN: Single factor analysis of variance.SETTING: Histological and Embryological Department and Neurobiological Department in Third Military Medical University of Chinese PLA.MATERIALS: The experiment was performed in Histological and Embryological Department and Neurobiological Department in Third Military Medical University of Chinese PLA. Twenty-five Wistar rats of 5 phases were employed, named embryonicphase (E8-E21), neonatal phase (P0-P15),childhood (P16-2 months), grown-up phase (＞ 2 months) and senile phase (＞ 8 months), 5 rats in each group.METHODS: In situ hybridization histochemistry (ISH) and immunohistochemistry (IHC) staining was adopted in brain sections from embryonic phase to senile phase.MAIN OUTCOME MEASURFS: Distribution and expression of positive cells of CDK-5 mRNA and protein in various brain areas.RESULTS: Twenty-five rats entered result analysis for all. ① The expression of CDK-5 mRNA presented in entire development from E14 to P350and was in tendency of stability after growth-up. CDK-5 mRNA localized mainly in neurons and positive regions distributed mainly in cerebral cortex, hippocampus, thalamus, hypothalamus, cerebellum and a part of nerve nuclei. ② The expression of CDK-5 was strong after birth and it was weaker in embryonic and senile rats. Positive regions concentrated mainly in peripheral ventricle, hippocampus, cerebellum and a part of nerve nuclei.The expression only presented in hippocampus and Purkinje cellular layer of cerebellum in senile rats.CONCLUSION: CDK-5 in brain runs through entire phases of neural development, it expresses more significantly in neonatal phase and childhood and declines after growth-up, especially in senile phase. The declined expression of CDK-5 in hippocampus of senile rats is closely associated with decline of learning and memory in senility probably.
