Abstract:

CT-HRP has been injected in the medial pterygoid rnuscle in adult rat(200～250 g body weight)to identify the cell of origin for the muscle endings. The labelled motoneurons in the ipsilateral trigeminal motor nucleus were observed. The motor neurons labelled with CT-HRP were approximately distributed throughout trigeminal motor nucleus. In the rostral level of the nucleus the labelled neurons were distributed in ventral-lateral part, in the middle level in lateral and ventral-lateral part and in the caudal level in lateral part. The size of the labelled motoneurons were estimated by measuring their diameters. The average long diameter of labelled cell bodies was 30. 85±6.71μm, ranging from 16～52μm. The average short diameter of labelled perikaryons was 19. 18±5.20 μm, ranging from 8～32μm. These results have been discussed.

Key words: medial pterygoid muscles, trigeminal motor nucleus, CT-HRP, rat