Dissociated neuronal culture of rats expressing insect odorant receptors as an odorant sensor

在活体中，人工气味传感器的性能通常比嗅觉系统差。气味感受器的分子识别能力和随之而来的神经元信息处理能力实现了生物气味系统的优异性能。为了利用这一点，我们提出了一种新型的混合型气味生物传感器，通过将昆虫的离子型气味受体表达到啮齿类动物的分离神经元培养中。这种材料组合带来了显著的优势，如易于功能表达，延长了寿命，并能够放大气味受体的弱离子电流。在本工作中，蚕蛾的信息素受体和辅助受体，即BmOR1和BmorOrco，通过脂质体转染法在神经元培养中表达。因此，BmOR1和BmorOrco在8%的神经细胞中共表达，两种受体共同定位在细胞膜上。在钙离子成像实验中，转染组和未转染组细胞在BOL出现时钙信号同步增强，且呈剂量依赖关系。这些结果为所提出的混合型气味生物传感器提供了概念验证。

Artificial odorant sensors generally perform poorer than olfactory systems in living organisms. The excellent performances of living odorant systems are achieved by the molecular recognition abilities of odorant receptors and the neuronal information processing that follows. To take advantages of this, here we propose a novel hybrid odorant biosensor by means of expressing ionotropic odorant receptors of insects into dissociated neuronal cultures of rodents. This combination of materials brings significant advantages such as easy functional expression, prolonged lifetime, and an ability to amplify the weak ionic currents of odorant receptors. In the present work, pheromone receptors and co-receptors of silkmoth, i. e., BmOR1 and BmorOrco, were expressed in neuronal cultures via liposome transfection. Consequently, BmOR1 and BmorOrco were co-expressed in 8% of neuronal cells, and both receptors were co-localized on a cell membrane. In Ca++imaging experiments, synchronous increase of calcium signals at the presentation of BOL was found in both transfected cells and non-transfected cells in a dose-dependent manner. These results provide the proof-of-concept of the proposed hybrid odorant biosensor.