Time-dependent inhibition of hindlimb somatic afferent inputs to nucleus tractus solitarius.
Time-dependent inhibition of hindlimb somatic afferent inputs to nucleus tractus solitarius.
复制标题
后肢躯体传入孤束核的时间依赖性抑制。
DOI：
10.1152/jn.1994.72.1.63
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发表时间：
1994
影响因子：
2.5
通讯作者：
Mifflin,SW
中科院分区：
文献类型：
--
作者：
Toney,GM;Mifflin,SW
1.本研究在麻醉、瘫痪的大鼠（n = 40）上进行了以下实验：（1）确定和表征孤束核（NTS）神经元对后肢躯体传入的反应：（2）确定向NTS的后肢躯体传入是否经历与内脏传入相似的时间依赖性抑制;和3）确定躯体传入诱发的NTS单位放电是否被压力感受器传入输入的激活改变。2.电刺激（约500微安）对侧胫神经（TN）（骨骼肌传入）、腓肠神经（SN）（皮肤传入）和同侧主动脉神经（AN）（压力感受器传入）后，记录了单个NTS单位的细胞外放电。为了确定可能的时间依赖性相互作用，采用了配对脉冲或调节测试刺激程序。NTS神经元的活动被记录在响应于测试刺激传递到TN或SN的情况下，然后在存在条件刺激传递到TN，SN，或AN 50，150，和250 ms之前的测试刺激。3.结果表明，在刺激体神经激活的31个NTS细胞中，有14个（约50%）同时接受来自TN和SN的会聚输入，9个只对TN刺激有反应，2个只对SN刺激有反应。这些细胞不是自发活动的，但表现出两种不同的诱发放电模式。有些人只有一个短的潜伏期，单峰反应，平均25.5 +/- 2.0（SE）ms的TN输入（n = 21）和27.9 +/- 2.8 ms的SN输入（n = 8）。（250字处删节）
1. In the present investigation, experiments were performed in anesthetized, paralyzed rats (n = 40) to 1) identify and characterize responses of nucleus tractus solitarius (NTS) neurons to hindlimb somatic afferent inputs; 2) determine if hindlimb somatic inputs to NTS undergo time-dependent inhibition similar to that observed among visceral afferent inputs; and 3) determine if somatic afferent-evoked NTS unit discharge is altered by activation of baroreceptor afferent inputs. 2. Extracellular discharge was recorded from single NTS units following electrical stimulation (approximately 500 microA) of the contralateral tibial nerve (TN) (skeletal muscle afferents), sural nerve (SN) (cutaneous afferents), and the ipsilateral aortic nerve (AN) (baroreceptor afferents). To identify possible time-dependent interactions, a paired pulse or conditioning-test stimulation procedure was employed. The activity of NTS neurons was recorded in response to test stimuli delivered to either TN or SN first in the absence and then in the presence of conditioning stimuli delivered to TN, SN, or AN 50, 150, and 250 ms before the test stimuli. 3. The results indicate that among 31 NTS cells activated by somatic nerve stimulation, 14 (approximately 50%) received convergent inputs from both the TN and SN, 9 responded to TN stimulation only and 2 were activated by SN stimulation only. These cells were not spontaneously active but showed two distinct patterns of evoked discharge. Some had only a short latency, unimodal response that averaged 25.5 +/- 2.0 (SE) ms for TN inputs (n = 21) and 27.9 +/- 2.8 ms for SN inputs (n = 8).(ABSTRACT TRUNCATED AT 250 WORDS)