Effect of membrane fluidity on brain receptors and transporters

神经药理学研究项目的目的是研究膜组成/流动性对大脑神经递质功能的影响。假设是膜组成和/或流动性的变化将对某些受体和转运蛋白以及某些脑区域产生特异性影响。我们建议在体外研究的剂量反应剂，硬化膜（胆固醇半琥珀酸酯和硬脂酸）相比，流化膜（亚油酸，L-α-磷脂酰胆碱和DHA，ω-3，广泛使用的营养补充剂）在牛脑膜。我们将研究流动性的变化如何影响多巴胺（D2），腺苷（A2 A），GABAA，5-羟色胺（5-HT 1A，5-HT 2A）谷氨酸（NMDA，mGluR 5）受体相比，多巴胺转运蛋白DAT。额叶皮层，海马和纹状体代表的范围从更多的流体更刚性的脑膜将进行研究。将使用荧光探针测量流动性。将通过蛋白质印迹法测定总膜受体和转运蛋白，并测定其结合特异性放射性配体的表面水平。将通过与第二信使和关键信号蛋白的偶联来测量功能变化。在大鼠体内，将对老年大鼠进行研究，研究表现出更坚硬膜的病症，而通过长期他汀类药物治疗、DHA治疗或缩醛磷脂（以增加DHA水平）治疗降低胆固醇，研究更多的流体膜。对于体内实验，我们还将通过原位杂交测量这些受体的mRNA以评估它们的合成。我们预计，小的膜变化将显着影响膜受体的研究，这具有重要的生理后果。可以施用影响膜的化合物（或设计饮食）以增强靶向这些受体和转运体的药物治疗的功效，从而成功老化。

The objective of this research program in neuropharmacology is to investigate the effect of membrane composition/fluidity on neurotransmitter function in the brain. The hypothesis is that changes of membrane composition and/or fluidity will have effects specific for certain receptors and transporters and specific for certain brain regions. We propose to investigate in vitro a dose-response of agents that rigidify membranes (cholesteryl hemisuccinate and stearic acid) compared to agents that fluidify membranes (linoleic acid, L-alpha-phosphatidylcholine and DHA, omega-3, a widely used nutritional supplement) in bovine brain membranes. We will investigate how fluidity changes affect dopamine (D2), adenosine (A2A), GABAA, serotonin (5-HT1A, 5-HT2A) glutamate (NMDA, mGluR5) receptors compared to the dopamine transporter DAT. The frontal cortex, the hippocampus and the striatum representing a range from more fluid to more rigid brain membranes will be studied. Fluidity will be measured with fluorescent probes. Total membrane receptors and transporters will be measured by Western blot and their surface levels with binding of specific radioligands. The functional changes will be measured with coupling to second messengers and key signaling proteins. In vivo in rats a condition presenting a more rigid membrane will be investigated with old rat whereas more fluid membranes will be investigated by reducing cholesterol with a chronic statin drug treatment, DHA treatment or plasmalogen (to increase DHA levels) treatment. For in vivo experiments we will also measure by in situ hydridization mRNA of these receptors to assess their synthesis. We expect that small membrane changes will significantly affect the membrane receptor investigated and that this has important physiological consequences. Compounds affecting membranes could be administered (or a diet designed) to enhance efficacy of drug treatments targeting these receptors and transporters for successful aging.