In Vivo Discharge Properties of Hypothalamic Paraventricular Nucleus Neurons With Axonal Projections to the Rostral Ventrolateral Medulla
In Vivo Discharge Properties of Hypothalamic Paraventricular Nucleus Neurons With Axonal Projections to the Rostral Ventrolateral Medulla
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DOI：
10.1152/jn.00094.2009
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发表时间：
2010-01-01
影响因子：
2.5
通讯作者：
Toney, Glenn M.
中科院分区：
文献类型：
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作者：
Chen, Qing-Hui;Toney, Glenn M.
Chen Q-H，Toney GM.轴突投射至延髓头端腹外侧的下丘脑室旁核神经元在体放电特性。J Neurophysiol 103：4 - 15，2010.首次发表于2009年11月4日; doi：10.1152/jn.00094.2009。下丘脑室旁核（PVN）和延髓头端腹外侧区（RVLM）是产生和调节交感神经活动（SNA）的神经网络的关键组成部分。虽然每个区域已被广泛研究，目前很少有人知道在体内放电特性的个别PVN神经元，直接支配RVLM。在此，在麻醉大鼠中进行细胞外记录，并使用逆向刺激来鉴定具有向RVLM的轴突投射的单个PVN神经元（n = 94）。将神经元分为两组，其具有终止于RVLM的无分支轴突（即，PVN-RVLM神经元，n = 65）或靶向RVLM和脊髓的侧支轴突[即，PVN-RVLM/中间外侧细胞柱（IML）神经元，n = 29]。PVN-RVLM（32/65，49%）和PVN-RVLM/IML（17/29，59%）神经元自发活动。各组的平均放电频率没有差异。峰电位触发平均显示，大多数神经元的自发放电与肾SNA时间相关（PVN-RVLM：12/21，57%; PVN-RVLM/IML：6/9，67%）。由心电图（ECG）R波触发的时间直方图表明，大多数细胞的放电也是心脏节律性的（PVN-RVLM：25/32，78%; PVN-RVLM/IML：10/17，59%）。升高和降低动脉血压以增加和减少动脉压力感受器输入导致两组细胞中放电频率的相应减少和增加（PVN-RVLM：9/13，69%; PVN-RVLM/IML：4/4，100%）。这些结果表明，PVN-RVLM和PVN-RVLM/IML神经元都能够参与基础交感神经活动及其压力反射调制。
Chen Q-H, Toney GM. In vivo discharge properties of hypothalamic paraventricular nucleus neurons with axonal projections to the rostral ventrolateral medulla. J Neurophysiol 103: 4-15, 2010. First published November 4, 2009; doi:10.1152/jn.00094.2009. The hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) are key components of a neural network that generates and regulates sympathetic nerve activity (SNA). Although each region has been extensively studied, little is presently known about the in vivo discharge properties of individual PVN neurons that directly innervate the RVLM. Here extracellular recording was performed in anesthetized rats, and antidromic stimulation was used to identify single PVN neurons with axonal projections to the RVLM (n = 94). Neurons were divided into two groups that had either unbranched axons terminating in the RVLM (i.e., PVN-RVLM neurons, n = 65) or collateralized axons targeting both the RVLM and spinal cord [i.e., PVN-RVLM/intermediolateral cell column (IML) neurons, n = 29]. Many PVN-RVLM (32/65, 49%) and PVN-RVLM/IML (17/29, 59%) neurons were spontaneously active. The average firing frequency was not different across groups. Spike-triggered averaging revealed that spontaneous discharge of most neurons was temporally correlated with renal SNA (PVN-RVLM: 12/21, 57%; PVN-RVLM/IML: 6/9, 67%). Time histograms triggered by the electrocardiogram (ECG) R-wave indicated that discharge of most cells was also cardiac rhythmic (PVN-RVLM: 25/32, 78%; PVN-RVLM/IML: 10/17, 59%). Raising and lowering arterial blood pressure to increase and decrease arterial baroreceptor input caused a corresponding decrease and increase in firing frequency among cells of both groups (PVN-RVLM: 9/13, 69%; PVN-RVLM/IML: 4/4, 100%). These results indicate that PVN-RVLM and PVN-RVLM/IML neurons are both capable of contributing to basal sympathetic activity and its baroreflex modulation.