Study on the long-term change of calcium homeostasis and kinetics in chronic epilepsy model
- VernacularTitle:慢性癫癎模型海马神经元内钙稳态和钙动力学的长期变化
- Author:
Wei WU
;
Zhaofu CHI
;
Xuewu LIU
;
Xiuhe ZHAO
;
Ning XU
;
Luming ZHAO
- Publication Type:Journal Article
- Keywords:
Epilepsy;
Hippocampus;
Neurons;
Calcium;
Disease models,animal
- From:
Chinese Journal of Neurology
2008;41(10):695-698
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the role of calcium homeostatic and kinetics in the epileptogenesis activity. Methods Hippocampal neurons were acutely isolated from controls and status epilepticus (SE) models induced by lithium-pilocarpine at different time point. The [Ca2+]i levels were detected by laser scanning confocal microscope. And the ability to restore resting [Ca2+]i levels after a brief exposure to 5 μmol/L glutamate in control and epileptic neurons were evaluated. Results The [Ca2+]i level of acute separated hippocampal neurons in the control rats was (95.4±22. 1) nmol/L After injection of lithium pilocarpine, the [Ca2+]i level in hippecampal neurons increased dramatically to (867.6±35.2) nmol/L, and decreased to (292.8 ± 18.3) nmol/L on the 7th day, lasting for about 30 days ((220. 8± 17.6) nmol/L), it is higher than that in the control group (t = 12. 55, P < 0.01). The distribution of neuronal [Ca22+]i showed that 92% of control neurons were in the normal range of [Ca2+]i level (25-150 nmol/L) ; After 6 hours, however [Ca2+]i levels of all SE neurons increased, and 85% of which were higher than 500 nmol/L; After 7, 14 and 30 days, there were 75%, 60% and 52% of SE neurons still manifested an elevated [Ca22+]i level, but less than 500 nmol/L. After the exposure to 5 μmol/L glutamate treatment for 2 minutes, [Ca2+]i of the control neurons restored to baseline values in (9. 5±3.4) minutes, whereas the SE rats of acute, latent and chronic phases did not (t = 5.08, 4. 56, 4. 21, all P < 0. 01). Conclusion Lithium-pilocarpine induced epilepsy causes a long-term alteration of calcium homeostatic mechanisms of hippocampus neurons, which may play an important role in the development and maintenance of spontaneous recurrent seizures.
