The cortical projection onto the paramedian reticular and perihypoglossal nuclei (nucleus praepositus hypoglossi, nucleus intercalatus and nucleus of roller) of the medulla oblongata of the cat. An experimental-anatomical study

Abstract

The projection from the sensorimotor cortex upon the paramedian reticular and perihypoglossal nuclei (nucleus praepositus hypoglossi of Marburg, nucleus intercalatus of Staderini and nucleus of Roller) of the medulla oblongata was studied in 17 adult cats, using the Nauta-Laidlaw method. The perihypoglossal nuclei as well as the dorsal subdivision of the paramedian reticular nucleus receive a modest bilateral cortical projection, originating chiefly in the ventral coronal gyrus (‘face’ region of the first somatomotor cortex). In addition some fibres pass to these nuclei from the first somatosensory area and from area 6 of Hassler and Muhs-Clement in the medial wall of the anterior sigmoid gyrus. The ventral subdivision of the paramedian reticular nucleus receives a modest bilateral projection from the anterior sigmoid and ventral coronal gyri (first somatomotor cortex). Some fibres pass to this nucleus from the first somatosensory area and from area 6 of Hassler and Muhs-Clement on the medial surface of the anterior sigmoid gyrus. These findings may suggest that the perihypoglossal nuclei and the dorsal subdivision of the paramedian reticular nucleus are in some way related to the motor functions of the tongue, whereas the ventral subdivision of the latter nucleus may be chiefly a link in a cerebrocerebellar pathway.