¹⁸F-FPEB Micro-PET Imaging Of Metabotropic Glutamate Receptor-5 In Aged Mice Brain

ObjectiveTo observe the changes of the brain metabolic glutamate receptor 5（mGluR5）in aged mice by using in vivo ¹⁸F-FPEB PET imaging and ex vivo western blot.Materials and MethodsThe male C57BL/6 mice of 2 months（young group）and 16 months（old group）were selected for our study.The change of anxiety level of old mice was measured by using the open field experiment.The two groups of mice underwent ¹⁸F-FPEB PET imaging scans respectively,and then the standard uptake value（SUV）was compared and analyzed.Western Blot was used to detect the expression of m GluR5 in the prefrontal cortex and hippocampus.Elisa was used to detect changes in plasma inflammatory factors.ResultsMicro-PET results showed that mGluR5 was significantly reduced in the whole brain region（striatum,hippocampus,cortex,thalamus,hypothalamus,and amygdala）with a significant decrease in the uptake of¹⁸F-FPEB.Western Blot results showed that the expression of mGluR5 in the prefrontal cortex and hippocampus of elderly mice decreased and there was a statistical difference compared with the young group（P<0.05）.Behavioral testing suggested that old mice behaved in an anxiety-like manner compared with the young group.Elisa results showed that IL-1βand TNF-αwere significantly elevated in aged mice,and IL-6 and IL-10 did not change significantly.ConclusionThe symptoms of anxiety in elderly mice may be related to body inflammation,and the expression of mGluR5 in the prefrontal cortex and hippocampus is significantly reduced,which may play an important role in it.The specific mechanism needs further study.