大鼠运动核内5-羟色胺1A、2A、5A受体的定位分布

IMMUNOHISTOCHEMICAL LOCALIZATION OF SEROTONIN 1A,2A,5A RECEPTORS IN THE MOTOR NUCLEI OF THE RAT

为了阐明５羟色胺在中枢神经系统内与运动神经元结合的精确部位，本研究用免疫细胞化学技术分别观察了大鼠躯体运动核和内脏运动核内５羟色胺１Ａ、２Ａ、５Ａ 受体的定位分布。在躯体运动核内观察到：（１）５羟色胺１Ａ 受体样阳性神经元和纤维主要分布于动眼神经核、滑车神经核、三叉神经运动核、面神经核、舌下神经核和脊髓前角；（２）５羟色胺２Ａ 受体样阳性神经元主要见于动眼神经核、三叉神经运动核、面神经核、舌下神经核和脊髓前角，但阳性纤维和终末却密集地分布于三叉神经运动核、面神经核、舌下神经核和脊髓前角等处，除此之外动眼神经核、滑车神经核、展神经核和疑核内也能见到中等密度的阳性纤维和终末，纤维和终末的分布范围和染色浓度、密度都较神经元为明显；（３）少量淡染的５羟色胺５Ａ 受体样阳性神经元和稀疏的阳性纤维及终末主要见于三叉神经运动核、面神经核、舌下神经核和脊髓前角。在内脏运动核内观察的结果是：（１）动眼神经副交感核（ＥＷ 核）、上涎核、迷走神经背核、骶髓副交感核和胸髓侧角内仅有少量５羟色胺１Ａ 受体样阳性神经元、纤维和终末分布；（２）５羟色胺２Ａ 受体样阳性神经元和较密集的阳性纤维和终末见于ＥＷ 核、迷走神经背核、骶?

In order to identify the precise binding sites of serotonin in motor nuclei of the brainstem and ventral and lateral horns of the spinal cord, the immunohistochemical staining method was used to observe the locations of serotonin 1A receptor (5 HT1AR),serotonin 2A receptor (5 HT2AR) and serotonin 5A receptor (5 HT5AR) in the somatic and visceral motor nuclei. In the somatic motor nuclei: (1)5 HT1AR like immunoreactive (LI) neurons and fibers were mainly found in the oculomotor, trochlear, trigeminal motor, facial, hypoglossal nuclei and spinal ventral horn; (2)5 HT2AR LI neuronal cell bodies were observed in oculomotor, trigeminal motor, facial, hypoglossal nuclei and spinal ventral horn, whereas 5 HT2AR LI fibers and terminals were densely encountered in trigeminal motor, facial, hypoglossal nuclei and spinal ventral horn, but in the oculomotor, trochlear, abducens and ambiguus nuclei, 5 HT2AR LI fibers and terminals were also moderately present; (3)A few lightly stained 5 HT5AR LI neuronal cell bodies, sparsely distributed fibers and terminals were mainly observed in the trigeminal motor, facial, hypoglossal nuclei and spinal ventral horn. In the visceral motor nuclei: (1)A few 5 HT1AR LI neuronal cell bodies, fibers and terminals were scattered in Edinger Westphal (E W) nucleus, superior salivatory nucleus, dorsal motor nucleus of vagus, sacral parasympathetic nucleus and thoracic lateral horn. (2)5 HT2AR LI neuronal cell bodies and quite dense 5 HT2AR LI fibers and terminals were observed in the E W nucleus, dorsal motor nucleus of vagus, sacral parasympathetic nucleus and thoracic lateral horn. (3)A few 5 HT5AR LI neuronal cell bodies were only found in the sacral parasympathetic nucleus and thoracic lateral horn, 5 HT5AR LI fibers and terminals were sparsely observed in the E W nucleus, dorsal motor nucleus of vagus, sacral parasympathetic nucleus and thoracic lateral horn. The present results indicate that: (1)There are 5 HT1AR, 5 HT2AR and 5 HT5AR in the somatic and visceral motor nuclei, but they do not distribute homogeneously; (2)5 HT might regulate the activities of somatic, sympathetic and parasympathetic motoneurons in the CNS by way of presynaptic and/or postsynaptic mechanism through 5 HT1AR,5 HT2AR and 5 HT5AR. (Figures 1～9 on plate 17)