Comparison of baroreceptive to other afferent synaptic transmission to the medial solitary tract nucleus
Comparison of baroreceptive to other afferent synaptic transmission to the medial solitary tract nucleus
复制标题
DOI：
10.1152/ajpheart.00568.2008
复制
发表时间：
2008-11-01
影响因子：
4.8
通讯作者：
Peters, James H.
中科院分区：
文献类型：
--
作者：
Andresen, Michael C.;Peters, James H.
Andresen MC，Peters JH.内侧孤束核压力感受性与其他传入突触传递的比较。Am J Physiol Heart Circ Physiol 295：H2032-H2042，2008。首次发表于2008年9月12日; doi：10.1152/ajpheart.00568.2008。颅神经内脏传入神经进入脑干，与孤束核（NTS）内的神经元形成突触。内脏传入和NTS神经元的广泛异质性使得理解传入突触传递特别具有挑战性。为了研究内侧NTS中二级神经元的特定亚群，我们用亲脂性荧光示踪剂（即，ADN+）和从水平脑干切片中的内侧NTS中的染料鉴定的神经元记录的对孤束（ST）激活的测量的突触反应。每个ADN+ NTS神经元接受恒定潜伏期ST诱发的兴奋性突触后电流（EPSC）（抖动< 192 μ s，潜伏期SD）。刺激募集曲线显示单一阈值，没有阈上募集，结果与EPSC从单一分支传入轴突产生一致。ADN+ EPSC的频率依赖性抑制平均类似于50 Hz下5次电击的70%，但单次电击失败率不超过4%。无论是邻近的ADN-或那些来自未标记的动物，其他二级NTS神经元（抖动）
Andresen MC, Peters JH. Comparison of baroreceptive to other afferent synaptic transmission to the medial solitary tract nucleus. Am J Physiol Heart Circ Physiol 295: H2032-H2042, 2008. First published September 12, 2008; doi:10.1152/ajpheart.00568.2008. Cranial nerve visceral afferents enter the brain stem to synapse on neurons within the solitary tract nucleus (NTS). The broad heterogeneity of both visceral afferents and NTS neurons makes understanding afferent synaptic transmission particularly challenging. To study a specific subgroup of second-order neurons in medial NTS, we antero-gradely labeled arterial baroreceptor afferents of the aortic depressor nerve (ADN) with lipophilic fluorescent tracer (i.e., ADN+) and measured synaptic responses to solitary tract (ST) activation recorded from dye-identified neurons in medial NTS in horizontal brain stem slices. Every ADN+ NTS neuron received constant-latency ST-evoked excitatory postsynaptic currents (EPSCs) (jitter < 192 mu s, SD of latency). Stimulus-recruitment profiles showed single thresholds and no suprathreshold recruitment, findings consistent with EPSCs arising from a single, branched afferent axon. Frequency-dependent depression of ADN+ EPSCs averaged similar to 70% for five shocks at 50 Hz, but single-shock failure rates did not exceed 4%. Whether adjacent ADN- or those from unlabeled animals, other second-order NTS neurons (jitters