大白鼠中脑水管周围灰质向小脑皮层的投射——HRP法研究

CEREBELLAR CORTICAL AFFERENTS FROM THE PERIAQUEDUCTAL GREY (PAG) IN THE RAT——A HRP STUDY

本研究应用HRP逆行追踪法研究了大白鼠中脑水管周围灰质(PAG)向小脑皮层的投射。结果表明:小脑皮层的所有注射区域均接受PAG的投射。PAG向同侧小脑皮层的投射多于对侧,两者之比约为3∶1。PAG-小脑皮层投射神经元主要位于PAG的中段和尾段的腹外侧区及内侧区的腹侧部,吻段很少见标记细胞。标记细胞以中、小型梭形和三角形细胞为主,偶见中型多极细胞;PAG尾段的尾端可见少量大型多极细胞。小脑和PAG均与许多内脏的功能活动有关。结合实验结果,讨论了此投射的机能意义。

A cerebellar afferent connection from the periaqueductal grey(PAG)has been demonstrated in the rat by means of retrograde transport of horseradish peroxidase(HRP)in the present study.The projection is bilateral,but the projection from the ipsilateral side is predominant(3:1).Its main origin is the ventromedial and ventrolateral regions of middle and caudal parts of PAG(98.8%),and the fibers reach different cerebellar cortical regions:culmen,declive,folium vermis,tuber vermis,pyramis vermis,uvula vermis,lobulus quadrangularis,crusⅠ,crusⅡ,and paraflocculus.Most labelled neurons are medium sized,but some small neurons also appear to project to cerebellum.Only a few large neurons are retrogradely labelled at the most caudal end of the caudal part.Functionally,both cerebellum and PAG are related to visceral activities.Consulting the present experiment,we discussed the significant role of the PAG-cerebellar projection.