Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies , La Jolla, CA 92037.
Department of Mechanical Engineering, University of Michigan , Ann Arbor, MI 48109.
eNeuro. 2017 Jan 5;3(6). doi: 10.1523/ENEURO.0175-16.2016. eCollection 2016 Nov-Dec.
Adults perform better than juveniles in food-seeking tasks. Using the nematode to probe the neural mechanisms underlying behavioral maturation, we found that adults and juveniles require different combinations of sensory neurons to generate age-specific food-seeking behavior. We first show that adults and juveniles differ in their response to and preference for food-associated odors, and we analyze genetic mutants to map the neuronal circuits required for those behavioral responses. We developed a novel device to trap juveniles and record their neuronal activity. Activity measurements revealed that adult and juvenile AWA sensory neurons respond to the addition of diacetyl stimulus, whereas AWB, ASK, and AWC sensory neurons encode its removal specifically in adults. Further, we show that reducing neurotransmission from the additional AWB, ASK, and AWC sensory neurons transforms odor preferences from an adult to a juvenile-like state. We also show that AWB and ASK neurons drive behavioral changes exclusively in adults, providing more evidence that age-specific circuits drive age-specific behavior. Collectively, our results show that an odor-evoked sensory code is modified during the juvenile-to-adult transition in animal development to drive age-appropriate behavior. We suggest that this altered sensory code specifically enables adults to extract additional stimulus features and generate robust behavior.
成年人在觅食任务中的表现优于青少年。通过线虫来探究行为成熟背后的神经机制,我们发现成年人和青少年需要不同组合的感觉神经元来产生特定年龄的觅食行为。我们首先表明,成年人和青少年对食物相关气味的反应和偏好不同,我们通过分析遗传突变体来绘制那些行为反应所需的神经元回路图。我们开发了一种新的设备来捕获青少年并记录他们的神经元活动。活动测量表明,成年和幼年 AWA 感觉神经元对添加二乙酰刺激有反应,而 AWB、ASK 和 AWC 感觉神经元则专门在成年个体中编码其去除。此外,我们表明,减少额外的 AWB、ASK 和 AWC 感觉神经元的神经传递会将气味偏好从成年样转变为青少年样。我们还表明,AWB 和 ASK 神经元仅在成年个体中驱动行为变化,这提供了更多证据表明特定年龄的电路驱动特定年龄的行为。总的来说,我们的结果表明,在动物发育过程中,从青少年到成年的过渡过程中,气味诱发的感觉代码会发生变化,从而驱动适当年龄的行为。我们认为,这种改变的感觉代码专门使成年人能够提取额外的刺激特征并产生强大的行为。