黄眉鹀上纹状体腹侧尾核的两条发声控制通路的探讨

用ＨＲＰ顺、逆行追踪方法，研究黄眉（ＥｍｂｅｒｉｚａＣｈｒｙｓｏｐｈｒｙｓ）端脑新纹状体前部大细胞核外侧部（ＩＭＡＮ）及嗅叶Ｘ区的纤维联系；并将ＨＲＰ溶液分别微电泳入端脑上纹状体腹侧尾核（ＨＶｃ）及古纹状体粗核（ＲＡ），观察其传出投射。结果发现：（１）ＩＭＡＮ接受丘脑背外侧核内侧部的传入投射，由ＩＭＡＮ发出的纤维投射至ＲＡ；（２）Ｘ区接受ＨＶｃ的传入投射，并发出纤维投射至丘脑背外侧核的内侧部；（３）ＨＶｃ发出两束纤维，分别投射至ＲＡ及Ｘ区；（４）ＲＡ也发出两束纤维，分别投射至中脑背内侧核及延髓舌下神经核气管鸣管部。因此ＨＶｃ可能通过两条路径控制发声行为：一条是ＨＶｃ直接投射至ＲＡ，再由ＲＡ支配延髓舌下神经核气管鸣管部的直接通路；另一条是ＨＶｃ→嗅叶Ｘ区→丘脑背外侧核内侧部→ＩＭＡＮ→ＲＡ的间接通路。后者可能参与发声学习和记忆等高级机能。

AN INVESTIGATION ON THE TWO VOCAL CONTROL PATHWAYS OF THE NUCLEUS HYPERSTRIATUM VENTRALE PARS CAUDALE IN EMBERIZA CHRYSOPHRYS

The two vocal control pathways from the nucleus haperstriatum ventrale pars caudale (HVc) to the robust nucleus of the archistriatum (RA) in En!beriza chrysophrys have been studied by using anterograde and retrograde HRP-TMB tract tracing method. After HRP was iontophoretically delivered into the lateral magnocellular nucleus of the anterior neostriatum (IMAN),dense anterogradely labelled terminals were observed in the ipsilateral RA. The retrogradely labelled neurons were found in the ipsilateral medial portion of the dorsolateral thalamic nucleus (DLM). After HRP was delivered into area X of lobus parolfactorius, some dense labelled neurons were concentrated in the ipsilateral HVc ,and the ventral area of Tsai (AVT). The labelled terminals were found in the ipsilateral DLM. After injecting HRP into the HVc ,the efferent projections were observed. There were dense anterogradely labelled terminals in the ipsilateral RA and area X. After injecting HRP into the RA ,anterogradely labelled terminals and fibers were found in nucleus dorsalis medialis of the midbrain (DM) and the pars tracheosyringealis of the hapoglossal nucleus (nⅦts). The results indicate that the IMAN receives projections from the DLM and projects to the RA. Area X receives projections from the HVc and projects to the DLM. The HVc projects to the RA,and to area X. The RA projects to the DM,and to the n Mts. All these projections are ipsilateral. Thus,there are two possible vocal control pathways in the telencephalon,one is the direct pathway from the HVc to the RA,the RA to the DM and n Ⅶ ts,the other is an indirect pathway from the HVc to area X,area X to the DLM,the DLM to the IMAN,and the MAN to the RA. The IMAN and area X are learning and memory centres. It is suggested that the indirect pathway may be involved in the song learning and memory functions.