GABAergic neurotransmission at the nucleus tractus solitarii in the suppression of reflex bradycardia by parabrachial nucleus
GABAergic neurotransmission at the nucleus tractus solitarii in the suppression of reflex bradycardia by parabrachial nucleus
复制标题
孤束核 GABA 能神经传递在臂旁核抑制反射性心动过缓中的作用
作者：
W. Len;J. Chan
在戊巴比妥麻醉的成年Sprague-道利大鼠中，我们研究了孤束核（NTS）的GABA能神经传递在臂旁核（PBN）复合体诱导的心脏压力感受性反射（BRR）反应抑制中的作用。基于体内微透析结合高效液相色谱-荧光检测γ-氨基丁酸（GABA），我们发现，电刺激PBN复合体的腹外侧区和Koelliker-korean（KF）亚核导致从NTS收集的透析液中GABA浓度的位点特异性增加。NTS中细胞外GABA浓度的时间增加与PBN诱导的心脏BRR抑制的时间过程一致。此外，通过向NTS双侧微量注射GABAA受体拮抗剂甲碘荷包牡丹碱（5 pmol）或GABAB受体拮抗剂2-OH saclofen（500 pmol），PBN诱导的心脏BRR抑制被逆转。用利多卡因（5%）阻断PBN复合体腹外侧区和KF亚核的神经元活动，引起相同反射反应的增强。利多卡因这种易化作用的时间过程与NTS中细胞外GABA浓度的时间降低呈正相关。在解剖学上，将逆行转运示踪剂显微注射到NTS中后，在PBN复合体的相同亚核中鉴定出Fast Blue标记的神经元。其中一些快蓝标记的神经元也对谷氨酸脱羧酶具有免疫反应性。这些结果表明，从KF亚核和周围区域的PBN复合体到NTS的直接GABA能下行投射可能通过激活NTS的GABAA和GABAB受体来抑制心脏BRR反应。Synapse 42：27-39，2001.© 2001 Wiley利斯公司
We investigated the role of GABAergic neurotransmission at the nucleus tractus solitarii (NTS) in the suppression of cardiac baroreceptor reflex (BRR) response induced by parabrachial nucleus (PBN) complex in adult Sprague‐Dawley rats maintained under pentobarbital anesthesia. Based on in vivo microdialysis coupled with high‐performance liquid chromatography‐fluorescence detection for γ‐aminobutyric acid (GABA), we found that electrical stimulation of the ventrolateral regions and Koelliker‐Fuse (KF) subnucleus of PBN complex resulted in a site‐specific increase in GABA concentration in the dialysate collected from the NTS. The temporal increase in extracellular GABA concentration in the NTS coincided with the time course of PBN‐induced cardiac BRR inhibition. In addition, the PBN‐induced cardiac BRR suppression was reversed by microinjection bilaterally into the NTS of a GABAA receptor antagonist, bicuculline methiodide (5 pmol), or a GABAB receptor antagonist, 2‐OH saclofen (500 pmol). Blockade of neuronal activity in the ventrolateral regions and KF subnucleus of PBN complex with lidocaine (5%) elicited an enhancement of the same reflex response. The time course of this facilitatory effect of lidocaine correlated positively with the temporal decrease in extracellular GABA concentration in the NTS. Anatomically, Fast Blue‐labeled neurons were identified in the same subnuclei of the PBN complex after microinjection of the retrograde transport tracer into the NTS. Some of these Fast Blue‐labeled neurons were also immunoreactive to glutamic acid decarboxylase. These results suggest that a direct GABAergic descending projection from the KF subnucleus and surrounding areas of the PBN complex to the NTS may inhibit cardiac BRR response by activating GABAA and GABAB receptors at the NTS. Synapse 42:27–39, 2001. © 2001 Wiley‐Liss, Inc.
影响因子：
3.7
作者：
BOURDELAIS, AJ;DEUTCH, AY
通讯作者：
DEUTCH, AY
DOI：
10.1016/0165-1838(88)90023-9
发表时间：
1988
期刊：
Journal of the autonomic nervous system
影响因子：
--
作者：
Urbanski,RW;Sapru,HN
通讯作者：
Sapru,HN