Real-time effects of nicotine exposure and withdrawal on neurotransmitter metabolism of hippocampal neuronal cells by microfluidic chip-coupled LC-MS

摘要

Nicotine ingested from smoking exerts neuroprotection and developmental neurotoxicity in central nervous system.It can produce several changes of cognitive behaviors through regulating the release of different neurotransmitters in the brain.However,the effects of nicotine exposure or withdrawal on neurotransmitter metabolism of hippocampus are still unclear.In this study,we real-time evaluated the dynamic alterations in neurotransmitter metabolism of hippocampal neuronal(HT22)cells induced by nicotine exposure and withdrawal at relevant exposure levels of smoking and secondhand smoke by using a microfluidic chip-coupled with liquid chromatography-mass spectrometry(MC-LC-MS)system.We found HT22 cells mainly released related neurotransmitters of tryptophan and choline metabolism,both nicotine exposure and withdraw altered its neurotransmitters and their metabolites release.Exposure to nicotine mainly altered the secretion of serotonin,kynurenic acid,choline and acetylcholine of HT22 cells to improve hippocampal dependent cognition,and the change are closely related to the dose and duration of exposure.Moreover,the altered metabolites could rapidly recover after nicotine withdrawal,but picolinic acid was elevated.MC-LC-MS system used in present study showed a greater advantage to detect unstable metabolites than conventional method by using in vitro model,and the results of dynamic alterations of neurotransmitter metabolism induced by nicotine might provide a potential targets for drug development of neuroprotection or cognitive improvement.