A biomimetic sensor using neurotransmitter detection to decode odor perception by an olfactory network

Mammalian olfactory perception is an important physiological function for tasks such as finding food, identifying species, and avoiding enemies. Previous studies have demonstrated the molecular basis of receptors and the anatomical structure of the olfactory bulb (OB), which is the initial processing center for odor perception. However, there remains some controversy about the coding and transmission mode of olfactory information in the OB through neuronal interaction mediated by different neurotransmitters. In this paper, a biomimetic sensor based on OB neuronal network was developed to detect trace amounts of typical neurotransmitters and decode odor perception in vitro. Primary OB neurons were seeded on a microelectrode array (MEA) chip to capture multichannel extracellular electrical activities. The firing features of OB neurons were statistically analyzed after stimulation with graded concentrations of the glutamate and gamma-aminobutyric acid (GABA). Cross-correlation analysis between channels was used to evaluate the connection status in the neuronal networks. The concentration-dependent responses to these two neurotransmitters were assessed over a range of values, and the lower limits of detection for glutamate and GABA were 100 nM and 50 nM, respectively. Stimulation with excessive concentrations produced response tolerance and neurotoxicity, and transmission between cells in the neural network was modulated by different neurotransmitters. This device could serve as a novel biosensor for detecting trace amounts of common neurotransmitters and for screening the effects of drugs on the physiology of olfaction. The response patterns of this biomimetic sensor are conducive to revealing the coding mechanism of information processing in the olfactory system.