TOPOGRAPHICAL PROJECTION BETWEEN THE PARABIGEMINAL NUCLEUS AND SUPERIOR COLLICULUS IN THE CAT——A RETROGRADE AND ANTEROGRADE STUDY WITH HRP / 解剖学报

ABSTRACT

The topographical projection between the parabigeminal nucleus and the superiorcolliculus in the cat was investigated by retrograde and anterograde HRP tracingtechnique.Following HRP injection in the rostral superior colliculus,the labeledsomata were found predominantly in the rostral region of contralateral parabigeminalnucleus,but labeled terminals were heavily distributed in the ipsilateral parabigeminalnucleus,mainly in the caudal region.Following injection of HRP into caudal superiorcolliculus,the labeled somata and terminals were seen in ipsilateral parabigeminalnucleus,chiefly in caudal part,but their number was significantly decreased.It wasnoted that the labeled somata were sparse but labeled terminals were not found inthe parabigeminal nucleus,when the injection was restricted to superficial layers ofsuperior colliculus.After HRP injection into deeper layers of superior colliculus,there existed not only the labeled somata but also the labeled terminals in theparabigeminal nucleus,the former was distributed in bilateral parabigeminal nucleus,the latter in ipsilateral nucleus,chiefly in the caudal part.These results show thatthere are topographical connections between the parabigeminal nucleus and superiorcolliculus,and the parental somata contributing axons to the parabigeminal nucleusare located in deeper layers of the ipsilateral superior colliculus.