Influence of tiantai No. 1 recipe on synaptic plasticity of the hippocampal CA1 region of spontaneous Alzheimer disease models: Quantitative research of ultrastructure

Ming LI; Zhengzhi WU; Yaofang LI; Yongfeng ZHANG; Xiuqin JIA; Manyin CHEN

ABSTRACT

BACKGROUND:

The synaptic plasticity of central nerves is the key basis of behavior-dependent learning and memory, there have been few reports about weather the Chinese herbal medicine for treatment of Alzheimer disease is through enhancing synaptic plasticity to improve learning and memory.

OBJECTIVE:

To investigate the effect of tiantai No. 1 recipe on learning and memory function and synaptic plasticity of spontaneous Alzheimer disease models.

DESIGN:

A randomized and controlled trial.

SETTING:

Institute of Combination of Traditional Chinese Medicine and Western Medicine of Shenzhen.MATERIALS The experiment was completed at the grade Ⅱ Laboratory of Institute of Combination of Traditional Chinese Medicine and Western Medicine of Shenzhen City. The experimental animals were mice of Kunming strain.

METHODS:

Totally 52 Kunming mice, aged 21 months, with spontaneous Alzheimer disease (memory impairment) were chosen, and at random divided into 4 groups senile dementia, western drug control, tiantai No. 1recipe 6.80 g/kg and 20.41 g/kg groups; besides 13 mice with normal learning and memory power were chosen as normal senile group. Hydergine 0.6 mg/kg was given for mice in western drug control group, tiantai No. 1recipe 6.80 g/kg and 20.41 g/kg were respectively given for mice in tiantai No. 1 recipe 6.80 g/kg and 20.41 g/kg groups. The medicines above were all prepared into 0.5 mL solution and given by gavage, for consecutive 60 days. The mice in normal senile and senile dementia groups were given double distilled water of the same volume. The learning memory power was tested by jumping stand; ultrathin cerebral section of hippocampal CA1 region was examined with transmission electron microscope,and some parameters of synaptic plasticity was also quantitatively detected with automatic micrographic analysis system.MAIN OUTCOME

MEASURES:

① The effect of tiantai No. 1 recipe in different doses on learning and memory of spontaneous Alzheimer disease mice. ② Observation of synapse with electron microscope and quantitative examination stereologically.

RESULTS:

All animals involved in the trial entered the final result analysis without any loss. ① The effect of tiantai No. 1 recipe in different doses on learning and memory of spontaneous Alzheimer disease mice The error numbers of learning and memory in tiantai No. 1 recipe 6.80 g/kg and 20.41 g/kg groups were smaller than that in senile dementia group,and the error number of learning in tiantai No. 1 recipe 6.80 g/kg group was smaller than that in tiantai No. 1 recipe 20.41 g/kg group. The escape latent periods of learning training was smaller than that in senile dementia group and the safe platform latent periods of memory in tiantai No. 1 recipe 6.80 g/kg and 20.41 g/kg groups were longer than that in senile dementia group, and the safe platform latent period of memory in tiantai No. 1 recipe 6.80 g/kg group was smaller than that in 20.41 g/kg group. ② Observation of synapse with electron microscope and quantitative examination stereologically Compared with the mice in normal senile group, for mice in senile dementia group, there occurred degenerative phenomena the number of synapses reduced, a part of synaptic clefts were not clear, the synaptic junction was interrupted, and he sizes of synaptic vesicles were different; in the rest groups there were also degenerative phenomena, however the degrees were milder than those in the model group. Tiantai No. 1 recipe could remarkably raise the number density and sectional density of synapses in the hippocampal CA1 region, and the increased extents in 20.41 g/kg tiantai No.1 recipe was larger than those in 6.80 g/kg tiantai No. 1 recipe.

CONCLUSION:

Tiantai No. 1 recipe can remarkably improve their learning and memory impairments, which may be related with that it promotes re-generation of synapse and improves the plasticity of cerebral synapses;and the action presented a relationship of dose-effect.