Bell Joseph S, Wilson Rachel I
Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
Neuron. 2016 Jul 20;91(2):425-38. doi: 10.1016/j.neuron.2016.06.011. Epub 2016 Jun 30.
The olfactory system is divided into processing channels (glomeruli), each receiving input from a different type of olfactory receptor neuron (ORN). Here we investigated how glomeruli combine to control behavior in freely walking Drosophila. We found that optogenetically activating single ORN types typically produced attraction, although some ORN types produced repulsion. Attraction consisted largely of a behavioral program with the following rules: at fictive odor onset, flies walked upwind, and at fictive odor offset, they reversed. When certain pairs of attractive ORN types were co-activated, the level of the behavioral response resembled the sum of the component responses. However, other pairs of attractive ORN types produced a response resembling the larger component (max pooling). Although activation of different ORN combinations produced different levels of behavior, the rules of the behavioral program were consistent. Our results illustrate a general method for inferring how groups of neurons work together to modulate behavioral programs.
嗅觉系统被分为不同的处理通道（嗅觉小球），每个通道接收来自不同类型嗅觉受体神经元（ORN）的输入信息。在此，我们研究了嗅觉小球如何协同作用以控制自由行走的果蝇的行为。我们发现，通过光遗传学方法激活单一类型的ORN通常会产生吸引行为，不过也有一些ORN类型会产生排斥行为。吸引行为主要由一个具有以下规则的行为程序构成：在虚拟气味出现时，果蝇逆风行走；在虚拟气味消失时，它们则掉头。当某些成对的具有吸引作用的ORN类型被共同激活时，行为反应的程度类似于各组成部分反应之和。然而，其他成对的具有吸引作用的ORN类型产生的反应类似于较大的组成部分（最大池化）。尽管激活不同的ORN组合会产生不同程度的行为，但行为程序的规则是一致的。我们的研究结果阐明了一种推断神经元群如何共同作用以调节行为程序的通用方法。
