Catecholaminergic neurons in synaptic connections with pre-Botzinger complex neurons in the rostral ventrolateral medulla in normoxic and daily acute intermittent hypoxic rats
Catecholaminergic neurons in synaptic connections with pre-Botzinger complex neurons in the rostral ventrolateral medulla in normoxic and daily acute intermittent hypoxic rats
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常氧和每日急性间歇性缺氧大鼠突触连接中的儿茶酚胺能神经元与延髓头端腹外侧前波青格复合体神经元
DOI：
10.1016/j.expneurol.2016.05.035
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发表时间：
2017-01-01
影响因子：
5.3
通讯作者：
Liu, Ying-Ying
中科院分区：
文献类型：
--
作者：
Kang, Jun-Jun;Liang, Wei-Hua;Liu, Ying-Ying
延髓头端腹外侧区（RVLM）含有心血管相关的儿茶酚胺能神经元和呼吸相关的前Botzinger复合体（pre-BotC）神经元，它们混合并在功能上连接以协调心肺活动。每日急性间歇性缺氧（dAIH）已知会引起呼吸可塑性。然而，目前还不清楚，如果儿茶酚胺能神经元直接突触到前BotC神经元，如果局部电路表现出可塑性时，暴露于dAIH。本研究旨在观察多巴胺-β-羟化酶（D β H）免疫反应（ir）的儿茶酚胺能神经元与神经激肽1受体（NK 1 R）免疫反应的前BotC神经元之间的突触表型，以及dAIH对神经元网络的影响。用免疫荧光组织化学方法观察了常氧和dAIH大鼠RVLM中D β H和NK 1 R的免疫反应。突触表型用免疫电镜双标记法检测。我们发现，DM免疫反应性表达的胞体和突起，其中一些是在密切的贴壁NK 1 R-ir前BaC神经元。D β H-IR金颗粒定位于胞体，树突和轴突终端。D β H-ir终末形成不对称的突触，偶尔，对称的突触在pre-BotC，具有本地电路。常氧组和dAIH组分别有28%和29.6%的突触与NK 1 R-ir树突并置。在dAIH组中发现DISH表达和NK 1 R-ir过程显著增加。此外，面积和数量的过程中密切appositions显着升高，强烈表明，dAIH诱导的可塑性与增加的连接和相互作用的心血管和泌尿相关的神经元在本地电路。总之，不对称突触是主要的在RVLM中的儿茶酚胺能神经元和前BotC神经元之间的串扰，阐述兴奋性传输驱动耦合的心肺活动。神经网络表现出可塑性响应dAIH的挑战。(C)2016 Elsevier Inc. All rights reserved.
The rostral ventrolateral medulla (RVLM) contains cardiovascular-related catecholaminergic neurons and respiratory -related pre-Botzinger complex (pre-BotC) neurons, which are intermingled and functionally connected for coordinating cardiorespiratory activities. Daily acute intermittent hypoxia (dAIH) is known to elicit respiratory plasticity. However, it is unclear if the catecholaminergic neurons directly synapse onto pre-BotC neurons, and if the local circuitry exhibits plasticity when exposed to dAIH. The present study was aimed to determine the synaptic phenotypes between dopamine-beta-hydroxylase (D beta H)-immunoreactive (ir) catecholaminergic neurons and neurokinin 1 receptor (NK1R)-ir pre-BotC neurons, and the effect of dAIH on the neuronal network. Immunofluorescence histochemistry was used to reveal immunoreactivities of D beta H and NK1R in the RVLM of normoxic and dAIH rats. Synaptic phenotypes were examined with double-labeling immunoelectron microscopy. We found that DM immunoreactivity was expressed in somata and processes, some of which were in close apposition to NK1R-ir pre-BaC neurons. D beta H-ir gold particles were localized to somata, dendrites, and axonal terminals. D beta H-ir terminals formed asymmetric synapses, and occasionally, symmetric synapses in the pre-BotC, featuring the local circuitry. Of the synapses, 28% in normoxic and 29.6% in dAIH groups were apposed to NK1R-ir dendrites. Significant increases in DISH expression and NK1R-ir processes were found in the dAIH group. Moreover, the area and number of processes in close appositions were significantly elevated, strongly suggesting that dAIH induced plasticity with increased connections and interactions between the cardiovascular and respiratory-related neurons in the local circuitry. In conclusion, asymmetric synapses are predominant in the crosstalk between catecholaminergic and pre-BotC neurons in the RVLM, elaborating excitatory transmission driving the coupling of cardiorespiratory activities. The neural network manifests plasticity in response to dAIH challenge. (C) 2016 Elsevier Inc. All rights reserved.