THE EFFECT AND MECHANISM OF ASTROCYTE ON SYNAPTIC FORMATION IN RATS
- VernacularTitle:大鼠星形胶质细胞在突触形成中的作用及机制
- Author:
Rong HU
;
Xigui WU
;
Zhong YANG
;
Lu WEI
;
Wenqin CAI
- Publication Type:Journal Article
- Keywords:
Astrocyte;
Neuron;
Synaptic formation;
Estrogen;
Estrogen receptor;
Immunofluorescence;
Cell culture;
Rat
- From:
Acta Anatomica Sinica
1955;0(03):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the effect of astrocyte on synapse formation and the molecular mechanism. Methods Cortical astrocytes were isolated and purified from neonatal rats.On the 2h,7th day,14th day and 21th day after passage,we counted the number of astrocytes and the culture medium(astrocyte-conditioned medium,ACM)was harvested to measure the concentration of estrogen(E 2)by using ELISA techniques.Based on the model of pure culures of neonatal cortical neurons,the experimental groups were designed as follows:1.pure neuron cultures(group N);2.ACM cultures(group A);3.mixed cultures(group M);4.E 2 cultures(group E 2);5.ACM+Tamoxifen(estrogen receptor antagonist)cultures(group A+T);6.Tamoxifen cultures(group T).Then synaptic puncta in every group was stained and counted through immunofluorescence,and we also compared the differences in puncta number among those six groups(at 9th day in culture,number/per neuron). Results The numbers of astrocytes were:1?10 4/ml, 1.1?10 6/ml, 1.4?10 6/ml, 1.5?10 6/ml; The concentrations of E 2 were:(ng/L):0, 117?22, 266?22,252?27 respectively.No estrogen was detected in the primary culture medium.The concenteration of estrogen increased in correspondence with the culturing days and reached the peak around at the 14th day, then decreased gradually but kept at a certain high level,and the numbers of synaptic puncta of per neuron in group N,A,M,E 2,A+T,T were:14?3;79?5;83?8;80?6;32?3;29?3 respectively.The treatment of pure neuron culture with ACM increased the number of synapses on per neuron by up to 6 fold by comparison with pure neuronal culture.Exogenic estradiol added into pure neurons can mimick the effect of the ACM.Tamoxifen which is antagonist of estrogen receptor could decrease the effect of ACM by 75%.Conclusion The astrocytes of neonatal rat cortex do secrete E 2.Astrocyte-derived estrogen may be the molecule regulating the synaptic formation through estrogen receptors.
