Octopaminergic neurons have multiple targets in Drosophila larval mushroom body calyx and regulate behavioral odor discrimination
Octopaminergic neurons have multiple targets in Drosophila larval mushroom body calyx and regulate behavioral odor discrimination
复制标题
八巴胺能神经元在果蝇幼虫蘑菇体花萼中具有多个靶标并调节行为气味辨别
DOI：
10.1101/295659
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Hilary Wong J
中科院分区：
文献类型：
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作者：
Hilary Wong J
对感官信号的辨别对于生物体在特定行为背景下形成和检索相关记忆是必不可少的。通过哺乳动物的去甲肾上腺素能输入或昆虫的章鱼胺（OA）所携带的信号，感觉表征会随着行为状态的变化而动态改变，促进情境依赖的行为选择。为了了解这种信号传导的回路机制，我们对两个OA神经元sVUM1的功能进行了表征，这两个神经元起源于食管亚区（SEZ），并以记忆中心的输入区域蘑菇体（MB）花萼为目标。我们发现sVUM1神经元可靶向多个神经元，包括嗅觉投射神经元（PNs）、抑制神经元APL和一对外源性输出神经元，但蘑菇体内禀神经元Kenyon细胞相对较少。PN末端携带OA受体Oamb，这是果蝇α1-肾上腺素能受体的同源物。利用气味识别学习范式，我们发现OA神经元的光遗传激活会损害对相似气味的识别，但不会影响学习能力。我们的研究结果表明，sVUM1神经元通过MB嗅觉学习回路的感觉输入区域的多个外部输入来修改气味表征。
Discrimination of sensory signals is essential for an organism to form and retrieve memories of relevance in a given behavioural context. Sensory representations are modified dynamically by changes in behavioral state, facilitating context-dependent selection of behavior, through signals carried by noradrenergic input in mammals, or octopamine (OA) in insects. To understand the circuit mechanisms of this signaling, we characterized the function of two OA neurons, sVUM1 neurons, that originate in the subesophageal zone (SEZ) and target the input region of the memory center, the mushroom body (MB) calyx, in larval Drosophila. We find that sVUM1 neurons target multiple neurons, including olfactory projection neurons (PNs), the inhibitory neuron APL, and a pair of extrinsic output neurons, but relatively few mushroom body intrinsic neurons, Kenyon cells. PN terminals carried the OA receptor Oamb, a Drosophila α1-adrenergic receptor ortholog. Using an odor discrimination learning paradigm, we showed that optogenetic activation of OA neurons compromised discrimination of similar odors but not learning ability. Our results suggest that sVUM1 neurons modify odor representations via multiple extrinsic inputs at the sensory input area to the MB olfactory learning circuit.