The development of the cervical part of the vagus nerve was studied by electron microscopy in 17 human embryos and fetuses from 18 to 220 mm crown-rump (CR) length, approximately 7--23 postovulatory weeks old. By the end of the embryonic period proper, processes of neurolemmocytes are beginning to invade the nerve bundles of the vagus. Early in the fetal… (More)
In embryos at stage 13th vestibulocochlear ganglion forms a complex structure with the geniculate ganglion. The geniculate ganglion is placed rostrally and may be distinguished from the vestibulocochlear ganglion. Also at this stage there is a sign of differentiation of the vestibular and cochlear ganglia.
The formation of the myelin sheath of the human phrenic nerve has been studied by electron microscopy in fetuses aged 15, 17, and 23 postovulatory weeks. At 15 weeks, the phrenic nerve is composed mainly of large bundles of axons surrounded by lemmocyte processes. However, fibres at the beginning of myelination are present and show one or one and a half… (More)
In 1989 Leitbrock et al. reported the full primary structure of brain-derived neurotrophic factor. The messenger RNA for BDNF was found predominantly in the central nervous system, and the sequence of protein indicated its structural relation to NGF. BDNF belongs to a larger family of neurotrophic molecules. It stimulates the neurite outgrowth and supports… (More)
A study was made on 18 embryos of developmental stages 13-15 (5(th) week). Serial sections made in horizontal, frontal, and sagittal planes were stained with routine histological methods and some of them were treated with silver. In embryos of stage 13, the otic vesicle is at the rhombomere 5, and close to the vesicle is the facial-vestibulocochlear… (More)
The primordia of the sympathetic trunk ganglia were traced on serial sections of 10 embryos at stage 13 (32 postovulatory days). It was found that in all embryos, these primordia were present in the thoracic level T4 to T9 and they appeared as scattered aggregates of cells lying dorsally and laterally to the dorsal aortae.
The aim of the study is to describe the differentiation of the cortical plate in human foetuses aged 9-11 weeks. Histological sections showed that in this early period of development the cortical plate is differentiated into two zones. The external zone is composed of vertical columns of cells, which are perpendicular to the cortical surface. The internal… (More)