Lewis Laurence P C, Siju K P, Aso Yoshinori, Friedrich Anja B, Bulteel Alexander J B, Rubin Gerald M, Grunwald Kadow Ilona C
Sensory Neurogenetics Research Group, Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany.
Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA.
Curr Biol. 2015 Aug 31;25(17):2203-14. doi: 10.1016/j.cub.2015.07.015. Epub 2015 Aug 20.
Animals continuously evaluate sensory information to decide on their next action. Different sensory cues, however, often demand opposing behavioral responses. How does the brain process conflicting sensory information during decision making? Here, we show that flies use neural substrates attributed to odor learning and memory, including the mushroom body (MB), for immediate sensory integration and modulation of innate behavior. Drosophila melanogaster must integrate contradictory sensory information during feeding on fermenting fruit that releases both food odor and the innately aversive odor CO2. Here, using this framework, we examine the neural basis for this integration. We have identified a local circuit consisting of specific glutamatergic output and PAM dopaminergic input neurons with overlapping innervation in the MB-β'2 lobe region, which integrates food odor and suppresses innate avoidance. Activation of food odor-responsive dopaminergic neurons reduces innate avoidance mediated by CO2-responsive MB output neurons. We hypothesize that the MB, in addition to its long recognized role in learning and memory, serves as the insect's brain center for immediate sensory integration during instantaneous decision making.
动物不断评估感官信息以决定下一步行动。然而，不同的感官线索往往需要相反的行为反应。大脑在决策过程中是如何处理相互冲突的感官信息的呢？在这里，我们表明果蝇利用归因于气味学习和记忆的神经基质，包括蘑菇体（MB），进行即时感官整合和对先天行为的调节。黑腹果蝇在取食发酵水果时必须整合相互矛盾的感官信息，这种水果会释放食物气味和天生厌恶的气味二氧化碳。在此，利用这个框架，我们研究了这种整合的神经基础。我们确定了一个局部回路，该回路由特定的谷氨酸能输出神经元和PAM多巴胺能输入神经元组成，它们在MB-β'2叶区域具有重叠的神经支配，整合食物气味并抑制先天回避行为。食物气味响应性多巴胺能神经元的激活会减少由二氧化碳响应性MB输出神经元介导的先天回避行为。我们推测，MB除了在学习和记忆中早已被认可的作用外，还作为昆虫大脑在即时决策过程中进行即时感官整合的中心。
