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.