ODOR DISCRIMINATION BY MITRAL CELLS IN RAT OLFACTORY BULB USING MICROWIRE ARRAY RECORDING

Response features of mitral cells in the olfactory bulb were examined using principal component analysis to determine whether they contain information about odorant stimuli.Using microwire electrode array to record from the olfactory bulb in freely breathing anesthetized rats,we recorded responses of different mitral cells to saturated vapor of anisole(1 M),carvone(1 M),isobutanol(1 M),citral(1 M)and isoamyl actate(1 M).The responses of single mitral cells to the same odorant varied over time.The response profiles showed similarity during certain amount of period,which indicated that the response was not only depended on odor itself but also associated with context.Furthermore,the responses of single mitral cell to different odorants were observed with difference in firing rate.In order to recognize different odorant stimuli,we apply four cells as a sensing group for classification using principal component analysis.Features of each cell’s response describing both temporal and frequency characteristics were selected.The results showed that five different single molecular odorants can be distinguished from each other.These data suggest that action potentials of mitral cells may play a role in odor coding.

Spatiotemporal coding of natural odors in the olfactory bulb

Smell that exists in the natural environment is composed of numerous odor molecules(Bushdid et al.,2014).The mammalian olfactory system can accurately identify environmental olfactory cues,including those related to food selection,recognition of conspecifics/predators,and emotional responses.

Evaluating the efficacy and cardiotoxicity of EGFR-TKI AC0010 with a novel multifunctional biosensor

Non-small cell lung cancer(NSCLC)is a leading cause of cancer mortality worldwide.Although epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs)have dramatically improved the life expectancy of patients with NSCLC,concerns about TKI-induced cardiotoxicities have increased.AC0010,a novel third-generation TKI,was developed to overcome drug resistance induced by EGFR-T790M mutation.However,the cardiotoxicity of AC0010 remains unclear.To evaluate the efficacy and cardiotoxicity of AC0010,we designed a novel multifunctional biosensor by integrating microelectrodes(MEs)and interdigital electrodes(IDEs)to comprehensively evaluate cell viability,electrophysiological activity,and morphological changes(beating of cardiomyocytes).The multifunctional biosensor can monitor AC0010-induced NSCLC inhibition and cardiotoxicity in a quantitative,label-free,noninvasive,and real-time manner.AC0010 was found to significantly inhibit NCI-H1975(EGFR-L858R/T790M mutation),while weak inhibition was found for A549(wild-type EGFR).Negligible inhibition was found in the viabilities of HFF-1(normal fibroblasts)and cardiomyocytes.With the multifunctional biosensor,we found that 10μM AC0010 significantly affected the extracellular field potential(EFP)and mechanical beating of cardiomyocytes.The amplitude of EFP continuously decreased after AC0010 treatment,while the interval decreased first and then increased.We analyzed the change in the systole time(ST)and diastole time(DT)within a beating interval and found that the DT and DT/beating interval rate decreased within 1 h after AC0010 treatment.This result probably indicated that the relaxation of cardiomyocytes was insufficient,which may further aggravate the dysfunction.Here,we found that AC0010 significantly inhibited EGFR-mutant NSCLC cells and impaired cardiomyocyte function at low concentrations(10μM).This is the first study in which the risk of AC0010-induced cardiotoxicity was evaluated.In addition,novel multifunctional biosensors can comprehensively evaluate the antitumor efficacy and cardiotoxicity of drugs and candidate compounds.

仿生嗅觉感知技术及其在嗅觉障碍疾病筛查中的研究进展

嗅觉障碍是多种疾病的早期症状,如新型冠状病毒感染的症状之一是嗅觉丧失,阿尔茨海默病和帕金森病患者通常伴有嗅觉降低或丧失.研究基于嗅觉功能检测的早期疾病筛查和诊断技术对控制患者病情、改善人类健康具有重要意义.目前嗅觉功能障碍的检测与评价方法尚不能有效地筛查和诊断各类嗅觉障碍相关疾病,而仿生嗅觉感知技术在模拟人类嗅觉感知系统方面具备一定的灵敏度、选择性和准确度,因此在嗅觉障碍相关疾病筛查中具有广阔的应用前景.本文介绍了目前国内外嗅觉功能障碍相关疾病的研究现状,分析了仿生嗅觉感知技术的原理及其在嗅觉障碍与疾病相关性检测与诊断中的研究进展.随着生物医学工程领域多学科交叉融合的发展,细胞网络芯片、类器官仿生芯片以及脑机交互技术的转化应用将促进仿生嗅觉感知技术在嗅觉障碍相关疾病研究中的发展以及临床疾病诊断技术的革新.

A high-sensitive detection method for carvone odor by implanted electrodes in rat olfactory bulb

Mammalian olfactory systems have extraordinary ability to sense and identify various trace odorants.Taking advantages of cell culture and micro-fabrication technologies,olfactory cell-or tissue-based biosensor represent a promising platform for in vitro odorant detection.However,in vitro conditions lead to shortened cell/tissue survivals,and the working life of neuron chips is short.The purpose of this study is to develop an in vivo recording and analyzing method for long-term and repeatable detection of odor stimulation.In this study,we implanted penetrating micro-wire array electrode into the olfactory bulb of conscious rats to obtain odor-evoked electrophysiological activities.Then,we investigated the response of ensembles of mitral/tufted cells to stimulation with carvone at a number of concentrations in time and frequency domains.The stable,repeatable odorant responses from up to 16 neural regions could be obtained for at least 3 weeks.Further,we explored the concentration detection sensitivity limitation of developed method,and found the detection low limit of carvone was below10-10mol/L.The result demonstrates that the concentration range of in vivo odorant detection method is much wider than in vitro method.