Parabrachial neurons mediate dorsal periaqueductal gray evoked respiratory responses in the rat.
Parabrachial neurons mediate dorsal periaqueductal gray evoked respiratory responses in the rat.
复制标题
臂旁神经元介导大鼠背侧导水管周围灰质诱发的呼吸反应。
DOI：
10.1152/japplphysiol.00903.2003
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Davenport,PaulW
中科院分区：
文献类型：
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作者：
Hayward,LindaF;Castellanos,Mabelin;Davenport,PaulW
介导行为防御反应的自主成分的神经基质位于导水管周围灰质（PAG）。背侧PAG（DPAG）诱发的防御反应的心血管成分已经得到很好的描述，部分依赖于臂旁核和延髓头端腹外侧区神经元的完整性。与DPAG神经元激活相关的介导兴奋反应的下行通路尚不清楚。本研究旨在验证臂旁区神经元也参与介导DPAG刺激的呼吸反应的假设。在麻醉的自主呼吸大鼠中，电刺激DPAG显著增加呼吸频率、动脉压和心率。呼吸频率的变化与吸气和呼气持续时间的显著减少相关。用5 mM蝇蕈醇（n= 6）双侧抑制外侧臂旁核（LPBN）区域的神经元后，DPAG诱发的呼吸和心率增加分别减弱90 ± 6和72 ± 13%。而刺激DPAG引起的升压反应仅减弱57 ± 6%。在LPBN中用20 mM犬尿烯酸（n= 6）双侧阻断谷氨酸受体也显著减弱了DPAG诱发的呼吸和心率增加（分别减少65 ± 15和53 ± 9%），但仅适度改变了DPAG诱发的升压反应（减少34 ± 16%）。这些结果表明，LPBN神经元在DPAG介导的行为防御反应的呼吸成分中起着重要作用。这一发现支持了以前的工作，证明背外侧脑桥在介导与DPAG激活相关的大多数生理调节中起着重要作用。
The neural substrates mediating autonomic components of the behavioral defense response reside in the periaqueductal gray (PAG). The cardiovascular components of the defense response evoked from the dorsal PAG (DPAG) have been well described and are dependent, in part, on the integrity of neurons in the region of the parabrachial nucleus as well as the rostral ventrolateral medulla. Descending pathways mediating the ventilatory response associated with activation of DPAG neurons are unknown. The present study was undertaken to test the hypothesis that parabrachial area neurons are also involved in mediating the respiratory response to DPAG stimulation. In urethane-anesthetized, spontaneously breathing rats, electrical stimulation of the DPAG significantly increased respiratory rate, arterial pressure, and heart rate. Changes in respiratory frequency were associated with significant decreases in inspiratory and expiratory durations. After bilateral inhibition of neurons in the lateral parabrachial nucleus (LPBN) region with 5 mM muscimol (n= 6), DPAG-evoked increases in respiration and heart rate were attenuated by 90 ± 6 and 72 ± 13%, respectively. The pressor response evoked by DPAG stimulation, however, was attenuated by only 57 ± 6%. Bilateral blockade of glutamate receptors with 20 mM kynurenic acid (n= 6) in the LPBN also markedly attenuated DPAG-evoked increases in respiration and heart rate (65 ± 15 and 53 ± 9% reduction, respectively) but only modestly changed the DPAG-evoked pressor response (34 ± 16% reduction). These results demonstrate that LPBN neurons play a significant role in the DPAG-mediated respiratory component of behavioral defense responses. This finding supports previous work demonstrating that the dorsolateral pons plays a significant role in mediating most physiological adjustments associated with activation of the DPAG.