Yu Hui Jing, Chen Xinnian, Foglyano Ryan M, Wilson Christopher G, Solomon Irene C
State University of New York at Stony Brook, Department of Physiology and Biophysics, USA.
Adv Exp Med Biol. 2008;605:393-8. doi: 10.1007/978-0-387-73693-8_69.
Numerous experimental preparations from neonatal rodents have been developed to study mechanisms responsible for respiratory rhythm generation. Amongst them, the in vivo anesthetized neonatal rat preparation and the in vitro medullary slice preparation from neonatal rat are commonly used. These two preparations not only contain a different extent of the neuroanatomical axis associated with central respiratory control, but they are also studied under markedly different conditions, all of which may affect the complex dynamics underlying the central inspiratory neural network. Here, we evaluated the approximate entropy (ApEn) underlying inspiratory motor bursts as an index of inspiratory neural network complexity from each preparation to address this possibility. Our findings suggest that the central inspiratory neural network of the in vivo anesthetized neonatal rat exhibits lower complexity (i.e., more order) than that observed in the in vitro transverse medullary slice preparation, both of which are substantially lower than that observed in more intact in vitro (e.g., arterially-perfused rat) and mature in vivo (e.g., anesthetized rat, piglet, cat) preparations. We suggest that additional studies be conducted to identify the precise mechanisms responsible for the differences in central inspiratory neural network complexity between these two neonatal rat preparations.
为了研究呼吸节律产生的机制，人们开发了许多来自新生啮齿动物的实验制剂。其中，体内麻醉新生大鼠制剂和新生大鼠的体外延髓切片制剂是常用的。这两种制剂不仅包含与中枢呼吸控制相关的不同程度的神经解剖轴，而且它们也是在明显不同的条件下进行研究的，所有这些都可能影响中枢吸气神经网络的复杂动态。在这里，我们评估了吸气运动爆发的近似熵（ApEn），作为每种制剂吸气神经网络复杂性的指标，以探讨这种可能性。我们的研究结果表明，体内麻醉新生大鼠的中枢吸气神经网络表现出比体外横向延髓切片制剂更低的复杂性（即更有序），这两种制剂都明显低于在更完整的体外（如动脉灌注大鼠）和成熟的体内（如麻醉大鼠、仔猪、猫）制剂中观察到的复杂性。我们建议进行更多的研究，以确定这两种新生大鼠制剂之间中枢吸气神经网络复杂性差异的精确机制。
