Early development of the hypoglossal nerve in the chick embryo as observed by the whole‐mount nerve staining method

Abstract

The developmental morphology of the hypoglossal nerve and associated structures were studied in the chick embryo (Hamburger and Hamilton stages 16-27) stained by the immunohistochemical technique. Ventral rootlets of the occipital nerves, including O1, were seen at stage 16. The distal ends of these nerves anastomosed to form the hypoglossal nerve at stage 20. At stage 23, four occipital and the first three cervical nerves were observed to be involved. The transient contribution of C3 at this stage seemed to be correlated with the formation of the longitudinal anastomosis of the distal end of the spinal nerves which begins around stage 23. The anterior hypoglossal roots appeared between O1 and the abducens nerve at stage 20. These rootlets were observed to arise as the rostral continuation of the occipital sequence and were found to be arranged in a straight line from O1 to the abducens nerve. The recurrent branch of the abducens was also observed. The posterior end of the ganglion crest produced dorsal root ganglion (DRG)-like structures transiently at the level of C2, and sometimes at the level of C1 also. The ganglion crest developed descending processes in the occipital region seemingly related to the spinal dorsal root formation. These phenomena seemed to represent the potential of the ganglion crest to produce the spinal nerve components which are depressed in the occipital region.

Loss of the Sall3 Gene Leads to Palate Deficiency, Abnormalities in Cranial Nerves, and Perinatal Lethality

“…Prior studies suggested that such transient ganglia can occur normally in vertebrates (33); however, these abnormalities were observed more often in Sall3 Ϫ/Ϫ animals. In half of the affected mutant animals, these supernumerary ganglia were also bilateral, while in the control animals, these structures were always unilateral (data not shown).…”

Isolation and Expression of PASK, a Serine/Threonine Kinase, During Rat Embryonic Development, with Special Emphasis on the Pancreas

“…In addition, a number of large ganglia in the CNS now showed strong pask expression. Froriep's ganglion, which is a vestigial DRG whose components later break down to give rise to the motor neuron elements of the hypoglossal (XII) ganglion (Kuratani et al 1988), the vestibulocochlear (VIII) ganglion, and the glossopharyngeal (IX) ganglion, all expressed pstk1. There was also continued expression of pstk1 in the myocardium and dorsal root ganglia.…”

Gross anatomical study of the sympathetic cardiac nerves in the house musk shrew (Suncus murinus)

“…The staining procedure was developed and verified in previous studies (Ishikawa et al, 1986;Kuratani et al, 1988aKuratani et al, , 1988b and used with some minor modifications as follows.…”

“…In this animal, symmetric large blood vessels, which have disappeared in most mammals during their evolutionary development, are preserved and optimal for providing clues about the arterial and venous portae, that is, the entrances to the heart of arteries and veins, because great vessels are considered to play a role as a guide for the peripheral sympathetic cardiac nerves from their origin to the heart. Whole-mount immunostaining is very useful to trace the three-dimensional structure of fine sympathetic cardiac nerves without making serial sections (Ishikawa et al, 1986;Kuratani et al, 1988aKuratani et al, , 1988b. Previously, Tanaka et al (1998) reported on the parasympathetic cardiac nerves in the house musk shrew, but no reports have been made on the sympathetic cardiac nerves in this species.…”