Department of Biology, Emory University, Atlanta, GA 30322, USA.
Neuroscience Graduate Program, Emory University, Atlanta, GA 30322, USA.
Cell Rep. 2024 Oct 22;43(10):114782. doi: 10.1016/j.celrep.2024.114782. Epub 2024 Sep 21.
How do neural circuits coordinate multiple behavioral responses to a single sensory cue? Here, we investigate how sweet taste drives appetitive behaviors in Drosophila, including feeding, locomotor suppression, spatial preference, and associative learning. We find that neural circuits mediating different innate responses to sugar are partially overlapping and diverge at the second and third layers. Connectomic analyses reveal distinct subcircuits that mediate different behaviors. Connectome-based simulations of neuronal activity predict that second-order sugar neurons act synergistically to promote downstream activity and that bitter input overrides the sugar circuit through multiple pathways acting at third- and fourth-order neurons. Consistent with the latter prediction, optogenetic experiments suggest that bitter input inhibits third- and fourth-order sugar neurons to override the sugar pathway, whereas hunger and diet act earlier in the circuit to modulate behavior. Together, these studies provide insight into how circuits are organized to drive diverse behavioral responses to a single stimulus.
神经回路如何协调对单一感官提示的多种行为反应？在这里，我们研究了甜味如何驱动果蝇的食欲行为，包括进食、运动抑制、空间偏好和联想学习。我们发现，介导对糖的不同先天反应的神经回路部分重叠，并在第二和第三层分化。连接组学分析揭示了介导不同行为的不同亚回路。基于连接组的神经元活动模拟预测，二阶糖神经元协同作用以促进下游活动，而苦味输入通过作用于第三和第四阶神经元的多条途径来超越糖回路。与后一预测一致的是，光遗传学实验表明，苦味输入抑制第三和第四阶糖神经元以超越糖通路，而饥饿和饮食则在回路的早期阶段调节行为。总的来说，这些研究提供了关于电路如何组织以驱动对单一刺激的多种行为反应的深入了解。
