Effects Of Deficiency Of Kidney-Yang And Pilous Anlter On Hippocampal Synaptic Plasticity

Objective: To clarify the essence of the relationship between kidney and brain in traditional Chinese medicine, we studied it using modern experimental technology and hypothesized it basing on the point of view in modern life science.Methods: 1.Empirical study: Hypothalamic-pituitary-adrenal axis disturbance (depression or potentiation) model, a model of deficiency of kidney-Yang, was used in the animal experiments. We observed the learning and memory performance of the different age of animals and the morphology changes in the hippocampus of these animals when the animals was administered the excessive corticosterone by subcutaneous injection or was adrenalectomized. Moreover, we established the model of apoptosis induced by corticosterone and explored the effect of gangliosides, which is a active component in pilous antler, on this apoptotic cell model. The effects of gangliosides on neurotransmitter release, neuronal filopodia formation, calcium signal cascade and 5-HTl A receptor-ligand competitive binding were also studied. 2. Theory study: The viewpoint on brain and kidney in traditional Chinese medicine and that in Western medicine were comparatively studied. The essence of the relationship between kidney and brain in traditional Chinese medicine Subsequently, in combination with the analysis on the results in the empirical study, we discussed the essence of the relationship between kidney and brain in traditional Chinese medicine from the viewpoint about the feedback mechanism of hippocampus-hypothalamic-pituitary-adrenal.Results: 1.Empirical study: The changes of learning and memory performances and hippocampal morphology were related to ageing. Both short-term and long-term administration of excessive glucocorticoids induced the decrease of learning and memory performances and hippocampal neurodegeneration. Adrenalectomy operated during both infancy and senectitude inhibited the hippocampal structure and function. Gangliosides antagonized the apoptosis induced by corticosteron, and the underlying mechanism is related to activiation of neuronal calcium signal cascade, promoting neurotransmitter release. Gangliosides also have an ability to promote the neuronal filopodia formation and may have a antidepressive-like neuroprotecive effect. 2. Theory study: We explained the clinical symptoms showed in the syndromes of deficiency of kidney-Yang and deficiency of kidney-Yin with modern scientific technical terms. Moreover, we supposed the location of kidney of traditional Chinese medicine may be in the hippocampus but not in the hypothalamus, which is also the centre of learning and memory.Conclusion: Hippocampal synaptic plasticity and learning performance of animals can be inhibited by the deficiency of kidney-Yang or kidney-Yin. The essence of the relationship between kidney and brain in traditional Chinese medicine was closed related to the feedback mechanism of hippocampus- hypothalamic-pituitary-adrenal. The target of tonifying kidney (modulating the function of hypothalamus-pituitary-adrenal) may be the maintenance of balance between glucocorticoid receptors and mineralcorticoid receptor.