Pre- and post-inspiratory neurons change their firing properties in female rats exposed to chronic intermittent hypoxia.
Pre- and post-inspiratory neurons change their firing properties in female rats exposed to chronic intermittent hypoxia.
复制标题
暴露于慢性间歇性缺氧的雌性大鼠中，吸气前和吸气后神经元的放电特性发生变化。
DOI：
10.1016/j.neuroscience.2019.03.043
复制
发表时间：
2019
期刊：
影响因子：
3.3
通讯作者：
Machado,BeneditoH
中科院分区：
文献类型：
--
作者：
Souza,GeorgeMPR;Barnett,WilliamH;Amorim,MateusR;Lima-Silveira,Ludmila;Moraes,DaviJA;Molkov,YaroslavI;Machado,BeneditoH
阻塞性睡眠呼吸暂停患者面临慢性间歇性缺氧（CIH）的发作，这已被认为是交感神经活动（SNA）增加和高血压的致病因素。暴露于CIH的雌性大鼠发展高血压，并表现出交感神经-交感神经耦合的变化，其特征在于SNA的吸气调制增加。我们测试了这一假设，即增强吸气调制SNA依赖于颈动脉体（CB），并与呼吸网络活动的变化。为此，在CIH雌性大鼠中，我们评估了CBs消融对交感神经-交感神经耦合的影响，记录了工作心脏-脑干制备中的呼吸神经元和脑干切片中的NTS神经元。CIH雌性大鼠的外周化学反射反应和NTS的自发兴奋性神经传递增加。CBs消融可防止CIH雌性大鼠SNA吸气调节的增加。CIH雌性大鼠的吸气前/吸气（Pre-I/I）神经元的放电频率降低。在CIH雌性大鼠呼气过程中，吸气后神经元活动时间较长。此外，使用脑干交感神经网络的计算模型，我们表明，减少前I/I神经元放电频率模拟增强吸气SNA调制CIH雌性大鼠。我们的结论是，CIH雌性大鼠的交感神经-交感神经耦合的变化依赖于CB，它与特定呼吸神经元类型的放电特性的变化有关。
Obstructive sleep apnea patients face episodes of chronic intermittent hypoxia (CIH), which has been suggested as a causative factor for increased sympathetic activity (SNA) and hypertension. Female rats exposed to CIH develop hypertension and exhibit changes in respiratory–sympathetic coupling, marked by an increase in the inspiratory modulation of SNA. We tested the hypothesis that enhanced inspiratory-modulation of SNA is dependent on carotid bodies (CBs) and are associated with changes in respiratory network activity. For this, in CIH-female rats we evaluated the effect of CBs ablation on respiratory–sympathetic coupling, recorded from respiratory neurons in the working heart–brainstem preparation and from NTS neurons in brainstem slices. CIH-female rats had an increase in peripheral chemoreflex response and in spontaneous excitatory neurotransmission in NTS. CBs ablation prevents the increase in inspiratory modulation of SNA in CIH-female rats. Pre-inspiratory/inspiratory (Pre-I/I) neurons of CIH-female rats have a reduced firing frequency. Post-inspiratory neurons are active for a longer period during expiration in CIH-female rats. Further, using the computational model of a brainstem respiratory–sympathetic network, we demonstrate that a reduction in Pre-I/I neuron firing frequency simulates the enhanced inspiratory SNA modulation in CIH-female rats. We conclude that changes in respiratory–sympathetic coupling in CIH-female rats is dependent on CBs and it is associated with changes in firing properties of specific respiratory neurons types.