大鼠脑干5-羟色胺能和儿茶酚胺能神经元向孤束核的投射——荧光金标记结合免疫荧光技术研究

A STUDY OF THE PROJECTIONS FROM SEROTONERGIC, CATECHOLAMIN ERGIC NEURONS TO THE NUCLEUS TRACTUS SOLITARII IN THE BRAINSTEM OF THE RAT

应用荧光金逆行追踪和免疫荧光技术相结合的方法，对投射至大鼠孤束核的５－羟色胺能和儿茶酚胺能神经纤维的脑干来源进行了研究。结果证明，将荧光金注入一侧孤束核的中尾段，逆标神经元分布于脑干下行抑制系统的大部分核团。结合５－羟色胺和酪氨酸羟化酶免疫荧光组织化学技术研究发现：荧光金／５－ＨＴ 双重反应阳性神经元分布于中脑导水管周围灰质的腹外侧区、中缝背核、脑桥被盖网状核、脑桥尾侧网状核、中缝桥核、中缝正中核、中缝大核、巨细胞网状核α部、中缝隐核和中缝苍白核等核团，其中中央灰质腹外侧区、中缝大核、巨细胞网状核α部、中缝隐核、中缝苍白核等处的荧光金／５－ＨＴ 双重反应阳性神经元数量占脑干向孤束核投射的５－ＨＴ 阳性神经元总数的近７０％ （６９．９１％ ）；荧光金／酪氨酸羟化酶双重反应阳性神经元主要分布于脑干中脑中央灰质腹外侧区、Ａ７、蓝斑及蓝斑下核（Ａ６）、Ａ５、巨细胞网状核α部和Ａ１ 等核团，其中中央灰质腹外侧区、Ａ５、巨细胞网状核α部和Ａ１ 内的荧光金／酪氨酸羟化酶神经元数量占脑干向孤束核投射的酪氨酸羟化酶阳性神经元总数的８８．１７％ 。本研究提示，大鼠脑干下行抑制系统形成了至ＮＴＳ中尾段的以中脑中央灰质腹外侧区及中缝大核、?

The method of fluoro gold(FG) retrograde tracing combined with immunofluorescence histochemistry were used to investigate the projections of serotonergic(5 HT) and catecholaminergic(CA) fibers from different parts of the whole brainstem to the nucleus tractus solitarii(NTS). After injecting FG into the mid caudal part of NTS, the FG retrogradely labeled neurons were found in most regions of the brainstem participating in the descending inhibitory system. The immunofluorescence histochemistry for 5 HT and TH showed that FG/5 HT double labeled neurons were distributed in the ventral lateral midbrain periaqueductal gray(vlPAG), dorsal raphe nucleus(DR), reticulotegmental nucleus of pons(RtTg), caudal pontine reticular nucleus(PnC), raphe pontis nucleus(RPn), median raphe nucleus(RMn), raphe magnus nucleus(RMg), nucleus reticularis gigantocellularis pars α(GiA), raphe obscurus nucleus(ROb) and raphe pallidus nucleus(RPa) in the brainstem. The proportion of FG/5 HT double labeled neurons in vlPAG, RMg, GiA, ROb and RPa was nearly 70%(69.91%) to total number of the 5 HT immunoreactive neurons in the brainstem. The FG/TH double labeled neurons were found in the vlPAG, A 7, locus coeruleus and sublocus coeruleus (A 6), A 5,GiA and A 1 in the brainstem. The proportion of FG/TH double labeled neurons in vlPAG, A 5, GiA and A 1 was 88.17% to total number of the TH immunoreactive neurons in the brainstem. The results of present study suggests that descending 5 HTergic and CAergic neurons in the rat brainstem, mainly the vlPAG, RMg, GiA, ROb, RPa and vlPAG, GiA, A 1, A 5, directly project to NTS, respectively. These direct projections may involve in modulation of the visceral activities and visceral, including nociceptive, informations of the chest and abdominal organs. (Figures 2,3 on plate 57,58)