NTS neurons with carotid chemoreceptor inputs arborize in the rostral ventrolateral medulla
NTS neurons with carotid chemoreceptor inputs arborize in the rostral ventrolateral medulla
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DOI：
10.1152/ajpregu.1996.270.6.r1273
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发表时间：
1996-06-01
影响因子：
2.8
通讯作者：
Guyenet, PG
中科院分区：
文献类型：
--
作者：
Koshiya, N;Guyenet, PG
在乌拉坦麻醉、迷走神经切断、主动脉去传入、人工呼吸大鼠(n=23)的孤束核(CNTs)尾部记录到由低氧刺激颈动脉化学感受器兴奋的神经元。这项研究的重点是26个化学敏感神经元(分为早反应和晚反应细胞)，这些神经元被化学感受器刺激而被张力激活，并且从未在与膈神经放电(PND)周期同步的爆发中被激发。早反应细胞(n=14)在PND刺激开始前开始放电至2.5 S，而晚反应细胞(n=14)在PND反应开始后开始放电1.5~5 S。4个早期反应细胞从延髓头端腹外侧区(RVLM；潜伏期：7-13ms)逆行激活，2个在疑核区域有轴突侧支。4个晚反应神经元从RVLM逆行激活(潜伏期：6-12ms)，但在该区域未发现侧支。早反应细胞和晚反应细胞的基础放电分别为0~10和0~30个/S，但大多数细胞的自发放电频率很低(中位数分别为0.2和0.6个/S)。两种类型都不是由压力感受器刺激引起的。碳纳米管还含有与PND周期同步的突发性放电的神经元。这些细胞是由化学感受器刺激激活的，而不是从RVLM反向激活的。RVLM逆行激活的CNTs神经元中，化学敏感神经元占33%(8/24)。综上所述，一群无呼吸调节作用的CNT化学敏感神经元通过RVLM投射并分布在该区域。
Neurons that were excited by hypoxic stimulation of carotid chemoreceptors were recorded in the caudal portion of the nucleus of the solitary tract (cNTS) of urethan-anesthetized, vagotomized, aortic-deafferented, artificially ventilated rats (n = 23). The focus of the study is on 26 chemosensitive neurons (classified as early- and late-response cells) that were tonically activated by chemoreceptor stimulation and never fired in bursts synchronized with the phrenic nerve discharge (PND) cycle. The discharge of early-response cells (n = 14) started up to 2.5 s before the onset of PND activation, whereas the discharge of late-response cells (n = 14) started 1.5-5 s after onset of PND response. Four early-response cells were antidromically activated from the rostral ventrolateral medulla (RVLM; latencies: 7-13 ms), and two had axonal collaterals in the region of the nucleus ambiguus. Four late-response neurons were antidromically activated from the RVLM (latencies: 6-12 ms), but no collateral was found in this area. The basal discharge of early- and late-response cells ranged from 0 to 10 and 0 to 30 spikes/s, respectively, but most of them had a very low spontaneous firing rate (median: 0.2 and 0.6 spikes/s, respectively). Neither type was excited by baroreceptor stimulation. The cNTS also contained neurons that were firing in bursts synchronized with the PND cycle. These cells were activated by chemoreceptor stimulation and were not antidromically activated from the RVLM. Chemosensitive neurons made up 33% of cNTS neurons antidromically activated from the RVLM (8/24). In conclusion, a population of cNTS chemosensitive neurons devoid of respiratory modulation projects through the RVLM and arborizes in this region.