Autoradiographic study of ascending projections from cardiovascular sites in the nucleus tractus solitarii in the cat
Autoradiographic study of ascending projections from cardiovascular sites in the nucleus tractus solitarii in the cat
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猫孤束核心血管部位上行投影的放射自显影研究
DOI：
10.1016/0006-8993(80)90989-0
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发表时间：
1980
期刊：
影响因子：
2.9
通讯作者：
F. Calaresu
中科院分区：
文献类型：
--
作者：
J. Ciriello;F. Calaresu
下丘脑接受来自心血管感受器的信息已被公认（如见参考文献4），但从孤束核（NTS）6、9、12中压力感受器和化学感受器纤维的第一中继到下丘脑的确切路线和分布仍未完全阐明。现有的实验证据，主要是神经解剖学，表明NTS中继心血管传入信息下丘脑通过中间连接在脑干网状formation 1，7，14-16，但最近的两项研究在大鼠报告了直接预测从NTS下丘脑17，18。为了支持这些最近的解剖学发现，刺激缓冲神经或NTS已被证明在猫4的单个下丘脑单位中引起短潜伏期反应。本研究通过放射自显影追踪技术提供猫NTS和下丘脑之间直接联系的证据8。通过蒸发市售标记的氨基酸（新英格兰Nuclear; L-[2，3-aH（N）]脯氨酸，spec. act. 25-30 Ci/mmol; L-[4，5- 3 H（N）]亮氨酸，特异性活性40-60 Ci/mmol）在真空离心机中干燥，并将其在生理盐水中重构以获得20- 100 μ Ci/μ l的浓缩溶液。使用与1/zl汉密尔顿注射器连接的玻璃微量移液管（尖端直径100-200 μ m）进行注射，所述注射器填充有同位素并牢固地保持在改良的Kopf电极保持器中。将11只猫（2.5-3.6 kg）（雌雄各半）用戊巴比妥钠麻醉（April Laboratories，Montreal，35 mg/kg，ip），并置于Kopf立体定位架中。通过部分切除枕骨并轻轻提起小脑蚓部，暴露延髓背侧表面。将同位素注射到NTS的右尾侧（n-5）和左尾侧（n-6）区域，该区域先前显示在电刺激期间引起低阈值心动过缓5。注射液由2040 nl含有等份[3 H]脯氨酸和[3 H]亮氨酸的溶液组成，在30 min内递送。
It is well established that the hypothalamus receives information from cardiovascular receptors (eg see ref. 4), but the exact course and distribution from the first relay of baroreceptor and chemoreceptor fibers in the nucleus tractus solitarii (NTS) 6, 9, 12 to the hypothalamus are still not completely elucidated. The available experimental evidence, mostly neuroanatomical, indicates that the NTS relays cardiovascular afferent information to the hypothalamus through intermediate connections in the brain stem reticular formation1, 7, 14-16, but two recent studies in the rat have reported direct projections from the NTS to the hypothalamus 17, 18. In support of these recent anatomical findings stimulation of either the buffer nerves or of the NTS has been shown to evoke short latency responses in single hypothalamic units in the cat 4. The present study was done to provide evidence of direct connections between the NTS and the hypothalamus in the cat by the autoradiographic tracing technique 8. The isotope solution was prepared by evaporation of the commercially available labeled amino acids (New England Nuclear; L-[2, 3-aH (N)] proline, spec. act. 25-30 Ci/mmol; L-[4, 5-3H (N)] leucine, spec. act. 40-60 Ci/mmol) to dryness in an evacuated centrifuge and reconstituting it in physiological saline to obtain a concentrated solution of 20-100# Ci/# l. A glass micropipette (tip diameter 100-200/~ m) connected to a 1/zl Hamilton syringe, filled with the isotope and firmly held in a modified Kopf electrode holder was used for injections. Eleven cats (2.5-3.6 kg) of either sex were anesthetized with pentobarbital sodium (Abott Laboratories, Montreal, 35 mg/kg, ip) and placed in a Kopf stereotaxic frame. The dorsal surface of the medulla was exposed by partial removal of the occipital bone and by gently lifting the vermis cerebelli. The isotopes were injected in the region of the right (n-5) and left (n--6) caudal half of the NTS, an area previously shown to elicit low threshold bradycardia during electrical stimulation 5. The injections consisted of 2040 nl of a solution containing equal parts of [3H] proline and [3H] leucine delivered in 30 min. After the injection the glass micropipette remained in place for at least 15 rain and was then