The Effects Of Unaggregated Amyloid β Protein (25-35) On MRNA Expression Of Potassium Channel In Pyramidal Neurons At Rat Hippocampal CA3

[Objective]Alzheimer's disease (AD) is a progressive neurodegenerative disease, which can injury the memory and cognitive abilities. Recent researches show that the cellular actions of B Protein (AB) play a quite important role in the neurodegeneration in AD. Aggregated AB has been proved to have clear neurotoxic effects, but the effects of unaggregated AB are unclear yet.The effects of unaggregated AB on the mRNA expression of Potassium Channel are studied in this experiment in order to clarify the mechanism of unaggregated AB in AD at ionic channel level, so that we can make sure the role of unaggregated AB played in the process of AD and provide testimonies for the clinical use of the potassium channel modulators, which probably can prevent and cure AD.[Methods]Combining the methods of enzymic digestion and mechanical separation, rat hippocampal CA3 pyramidal neurons can be separated from the slice of the brain tissue. Then we use the patch clamp technique to get a single cell, and use the RT-PCR technique to amplify potassium channels' mRNA, so that we can record the effects of unaggregated amyloid B protein (25-35) on the mRNA expression of potassium channels subtype Kv2.1, Kv1.4, Kv4.2.[Results]1. Delayed rectification potassium channel Kv2.1 and transient outward potassium channel Kv4.2> Kvl.4 have a relatively abundant expression in the in rat hippocampal CA3 Pyramidal Neurons.2. Unaggregated amyloid 6 protein (25-35) has a dominant inhibitory action on the mRNA expression of potassium channel subtype Kv2.1 and the inhibitory action has time dependence and concentration dependence.3. Unaggregated amyloid B protein (25-35) does not show a dominant inhibitory action on the mRNA expression of potassium channel subtype Kvl.4 and Kv 4.2.