Developmental mechanisms from tetal to neonatal type of respiratory center as a functional neuron network

从四肢到新生儿型呼吸中枢作为功能神经元网络的发育机制

基本信息

批准号：
13680880
负责人：
ONIMARU Hiroshi
金额：
$ 1.73万
依托单位：
Showa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

We analyzed intrinsic burst generating property of respiratory neurons in the medulla of the rat fetus. In the E17-20 preparations that showed the fetal type-C4 inspiratory burst pattern, about 60% of inspiratory neurons exhibited voltage-dependent burst activity. In E19 preparations, the input resistance of the bursting neurons was significantly higher than that of non-bursting cells. Membrane capacitance tended to be lower (but not significant) in the bursting neurons than in the non-bursting cells. Since the bursting neurons still kept the bursting activity in the low Ca2+/high Mg2+ solution, we concluded that they possess intrinsic burst generating properties.Using optical recordings, we analyzed respiratory neuron network activity in the ventral medulla of fetus stained with voltage-sensitive dye. In E20/21 preparations, respiratory neuron activity appeared in the limited area of the rostral ventrolateral medulla (para-facial respiratory group, pFRG), and propagated mainly caudall … More y. Then, during the inspiratory phase, the peak of activity was detected, caudally, in the caudal ventrolateral medulla (CVLM) and, rostrally, in the mainly lateral and medial region of the facial nucleus. Such pattern was basically identical to that of neonatal rat preparations. In contrast, in all of El7 and most of El8 preparations, respiratory activity first appeared in the CVLM region, coincidently with the start of inspiratory burst, and then propagated rostrally. Successively, strong activity appeared in the whole region of the facial nucleus and continued 1-3 sec after termination of C4 inspiratory activity. In half of E19 preparations, respiratory activity started from the pFRG (neonatal type), whereas it started from the CVLM inothers (fetal type). However, even in the preparations that showed the neonatal type-network activity pattern, C4 inspiratory activity was the fetal type showing short burst duration. We suggest that the primary rhythm generating network and the spatio-temporal pattern develops to the neonatal type before the neuron network generating inspiratory activity does. Less

我们分析了大鼠胎儿髓质中呼吸神经元的内在爆发生成特性。在显示胎儿 C4 型吸气爆发模式的 E17-20 制剂中，约 60% 的吸气神经元在 E19 制剂中表现出电压依赖性爆发活动。，爆发神经元的输入电阻显着高于非爆发细胞，而爆发神经元的膜电容往往低于（但不显着）。由于爆发神经元在低 Ca2+/高 Mg2+ 溶液中仍保持爆发活性，因此我们得出结论，它们具有内在的爆发生成特性。利用光学记录，我们分析了胎儿腹侧髓质的呼吸神经元网络活动。用电压敏感染料染色，在延髓头端腹外侧的有限区域（面旁呼吸组， pFRG），并主要传播到尾部……更多 y。然后，在吸气相，在尾部腹外侧髓质（CVLM）和头侧，在面核的主要外侧和内侧区域检测到活动峰值。这种模式与新生大鼠制剂的模式基本相同。相反，在所有El7和大多数El8制剂中，呼吸活动首先出现在CVLM区域，巧合的是。随着吸气爆发的开始，然后成功地传播到面部核的整个区域，并在 C4 吸气活动终止后持续 1-3 秒。在一半的 E19 制剂中，呼吸活动从 pFRG 开始。（新生儿型），而其他（胎儿型）则从 CVLM 开始。然而，即使在显示新生儿型网络活动模式的制剂中，C4 吸气活动。我们认为，初级节律生成网络和时空模式在生成吸气活动的神经元网络之前发展为新生儿类型。