上橄榄复合体向下丘γ-氨基丁酸能投射

GABAergic Neurons of Superior Olivary Complex Projection to Inferior Colliculus

目的 研究γ－氨基丁酸（ＧＡＢＡ）阳性神经元在豚鼠上橄榄复合体的分布及向下丘的投射。方法采用辣根过氧化物酶（ＨＲＰ）逆行追踪和免疫组化ＡＢＣ技术。结果 上橄榄复合体ＨＲＰ标记神经元主要分布在双侧的上橄榄外侧核（ＬＳＯ）、同侧的上橄榄内侧核（ＭＳＯ）、上橄榄周围核（ＰＮ）及斜方体腹侧核（ＶＮＴＢ）。双侧的斜方体外侧核（ＬＮＴＢ）及背侧核（ＤＮＴＢ）未见ＨＲＰ阳性标记神经元。ＧＡＢＡ阳性反应结构在上橄榄复合体的分布具有较明显的特征性。阳性神经元主要分布在ＬＳＯ、ＤＮＴＢ及ＰＮ内，多呈圆形、卵圆形，直径约１６～４０μｍ，突起较短。阳性点状终末主要分布在ＶＮＴＢ及ＬＮＴＢ，以ＶＮＴＢ数量较多。ＬＳＯ和ＰＮ内均发现ＨＲＰ－ＧＡＢＡ双标细胞，约占标记细胞的三分之一。结论 豚鼠上橄榄复合体有ＧＡＢＡ阳性神经元和终末分布；橄榄内侧和外侧系统均有向下丘投射的神经元；在ＬＳＯ、ＤＮＴＢ和ＰＳＯ内，有ＧＡＢＡ能神经元向下丘的上行投射。

Objective To investigate the distribution of gamma - aminobutyric acid( GABA) positive neurons in superior olivary complex( SOC) and projection to inferior collicullus of guinea pigs. Methods Immunohistochemical ABC method and HRP retrograde tracing technigue were used in this study. Results The labelled - HRP positive neurons were distributed mainly in ipsilateral and contralateral lateral superior olive (LSO) and in ipsilateral medial superior olive (MSO), periolivary nuclueus (PN), ventral nucleus of the trapazoid body(VNTB), HRP - labelled neurons could not he found in ipsilateral and contralareral lateral nucleus and dorsal nucleus of the trapezoid body(LNTB, DNTB). There were obviously characteristic distribution of GABA positive products in SOC, positive neurons, round or veal - shaped with a diameter about 16-40 μm and shorter projects exsited predominently in LSO, DNTB and PN. Puncta - like endings were distributed mainly in VNTB and LNTB, especially in VNTB. HRP - GABA doubled labelled neurons were found in LSO and PN, and about 1/3 of all labeled neurons were double - labelled. Conclusion There are GABA positive neurons and endings in SOC. There are neurons projection to inferior colliculus in medial and lateral system of SOC. In LSO and PN, Some of these neurons are GABAergic.