Institute of Anatomy I: Cellular Neurobiology, University Medical Center, 20246 Hamburg, Germany.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2010 Jan;196(1):37-50. doi: 10.1007/s00359-009-0490-z. Epub 2009 Nov 19.
This study analyses the maturation of centrally generated flight motor patterns during metamorphosis of Manduca sexta. Bath application of the octopamine agonist chlordimeform to the isolated central nervous system of adult moths reliably induces fictive flight patterns in wing depressor and elevator motoneurons. Pattern maturation is investigated by chlordimeform application at different developmental stages. Chlordimeform also induces motor patterns in larval ganglia, which differ from fictive flight, indicating that in larvae and adults, octopamine affects different networks. First changes in motoneuron activity occur at the pupal stage P10. Rhythmic motor output is induced in depressor, but not in elevator motoneurons at P12. Adult-like fictive flight activity in motoneurons is observed at P16 and increases in speed and precision until emergence 2 days later. Pharmacological block of chloride channels with picrotoxin also induces fictive flight in adults, suggesting that the pattern-generating network can be activated by the removal of inhibition, and that proper network function does not rely on GABA(A) receptors. Our results suggest that the flight pattern-generating network becomes gradually established between P12 and P16, and is further refined until adulthood. These findings are discussed in the context of known physiological and structural CNS development during Manduca metamorphosis.
这项研究分析了烟青虫变态过程中中枢产生的飞行运动模式的成熟。将章鱼胺激动剂氯苯甲脒应用于离体成年飞蛾的中枢神经系统，可靠地诱导了翅降肌和升肌运动神经元的拟飞行模式。通过在不同发育阶段应用氯苯甲脒来研究模式成熟。氯苯甲脒也诱导了幼虫神经节中的运动模式，与拟飞行不同，这表明在幼虫和成虫中，章鱼胺影响不同的网络。在蛹期 P10 首先发生运动神经元活动的变化。在 P12 时，诱导降肌而不是升肌运动神经元产生节律性运动输出。在 P16 观察到类似于成虫的拟飞行活性，并且速度和精度增加，直到 2 天后出现。用 picrotoxin 阻断氯离子通道也会在成虫中诱导拟飞行，这表明模式生成网络可以通过去除抑制来激活，并且适当的网络功能不依赖于 GABA(A)受体。我们的结果表明，飞行模式生成网络在 P12 和 P16 之间逐渐建立，并在成年期进一步细化。这些发现是在烟青虫变态过程中已知的生理和结构中枢神经系统发育的背景下讨论的。
