大鼠延髓腹外侧表面化学感受区与延髓内部核团的联系

NEURAL STRUCTURAL RELATIONS BETWEEN THE CHEMOSENSITIVE AREAS OF THE VENTROLATERAL MEDULLLARY SURFACE AND THE MEDULLARYNUCLEI IN RATS

本文采用辣根过氧化物酶（ＨＲＰ）组化方法，对大鼠延髓腹外侧表面化学感受区与延髓内部核团之间的神经结构联系进行了系统的探查。实验在３０只麻醉且自主呼吸的雄性ＳＤ大鼠上分四组进行。用ＨＲＰ滤纸分别局部敷贴于延髓腹外侧表面的头端化学感受区（Ｒ区，ｎ＝１０）、尾端化学感受区（Ｃ区，ｎ＝１０）、中间区（Ⅰ区，ｎ＝６）和对照区（ｎ＝４）。动物存活２４ｈ后，检查ＨＲＰ标记细胞所在的核团部位。（１）于Ｒ区表面敷贴ＨＲＰ后，在延髓斜方体核（Ｔｚ）、外周橄榄腹外侧核（ＬＶＰＯ）和斜方体后核（ＮＲＴ）均有ＨＲＰ标记细胞存在。（２）于Ｃ区表面敷贴ＨＲＰ后，在延髓的巨细胞旁外侧核（ＬＰＧｉ）、外侧网状核（ＬＲｔ）和舌下神经核有ＨＲＰ标记细胞存在。（３）于Ⅰ区表面敷贴ＨＲＰ后，在６只大鼠的延髓内部区域仅观察到８个ＨＲＰ标记细胞，它们散在地分布于巨细胞旁外侧核的腹侧部分。（４）于对照区敷贴ＨＲＰ后，在４只大鼠的延髓内部区域仅观察到６个ＨＲＰ标记细胞，它们散在地分布在头端腹外侧网状核（ＲＶＬ）。上述结果提示：Ｔｚ，ＬＶＰＯ，ＮＲＴ，ＬＰＧｉ和ＬＲｔ等延髓内部核团与腹外侧表面化学感受区之间存在神经结构联系，这可能为延髓腹侧面起化学感受器作用?

Experiments were done on 30 chloralose-urethane anesthetized Sprague-Dawley strain rats. The ventrolateral medullary surface was exposed and a small millipore filter paper soaked with horse radish peroxidase (HRP) was applied locally to different parts of the underlying chemosensitive areas separately, trying to identify location of the HRP-stained cells. (1) After HRP application to the rostral area (n=10), quite a number of labelled cells were distributed at the ventrolateral part of the nucleus of trapezoid body (Tz), the lateroventral periolivary nucleus (LVPO) and the retrotrapezoid nucleus (NRT). (2) After HRP application to the caudal area (n=10), HRP labelled cells were mainly located at the lateral reticular nucleus (LRt) and the ventral part of at the lateral paragigantocellular nucleus LPGi. (3) After HRP application to the intermediate area (n=6), only 8 HRP labelled cells were observed at the (LPGi) in 6 rats. (4) After HRP application to the control area (n=4), only 6 HRP labelled cells were found at the rostral ventrolateral reticular nucleus (RVL). The above findings demonstrated the existence of the neural structural relations between the chemosensitive areas of the ventrolateral medullary surface and Ti, LVPO, NRT, LPGi, LRt, which supports that all these nuclei might participate in the central chemoreception of respiration.