Macroscopic, mesoscopic and microscopic morphology of the gastric plexus--ontogeny of the celiac ganglion.

The vagus trunks, anterior and posterior, and their respective branches control the parasympathetic innervation of the stomach. After giving off a few thin branches, at the lower part of the esophagus and the cardiac region of the stomach, the anterior vagal trunk divides into its main branches: four or five consecutive direct branches which supply the upper part of the lesser curvature; these nerves do not form plexuses and thus, they may be individually dissected. One of the branches is stronger than the others and is called the principal anterior nerve of the lesser curvature (anterior nerve of Latarjet). The present study was conducted on eight fetuses of different gestational age (resulting from spontaneous abortions, without malformations), observing the Romanian laws of professional ethics, and 15 adult cadavers (male and female) whose celiac region was dissected macro- and mesoscopically to reveal both the celiac ganglia and their afferent and efferent vessels. For the microscopic study, we used the Bielschowsky silver staining method. The meso- and macroscopic dissections revealed the anterior and posterior vagal trunks in all the specimens (100%), as well as a rich gastric periarterial plexus. The microscopic samples focused on the ontogeny of the celiac ganglion in various gestational stages.

Enteric nervous system development in cavitary viscera allocated to the celiac plexus.

Enteric nervous system (ENS) is a network made of neuronal cells and nervous fibers. There are two plexuses: myenteric of Auerbach and sub mucous of Meissner and Henle. Many substances are involved in neurotransmission at ENS level. ENS assures all gastrointestinal system functions: digestion, absorption, etc. Our study is made on 23 human fetal specimens at different ages of evolution with crown-rump lengths from 9 to 28 cm, and three new born human specimens. We used the Trichrome Masson stain technique and the argental impregnation Bielschowsky on block technique for microscopic evidence. Our study concerned the cavitary viscera allocated to the celiac plexus, involving all layers of each studied viscera.

Neurochemical differentiation of functionally distinct populations of autonomic neurons.

The coeliac ganglion of guinea pigs displays a unique topographical arrangement of neurochemically and functionally distinct populations of sympathetic neurons. The authors used multiple-labeling immunohistochemistry to investigate the neurochemical differentiation of these neurons during embryonic and fetal development. Sympathoadrenal precursors, located on either side of the abdominal aorta, were intensely immunoreactive for tyrosine hydroxylase (TH-IR), neurofilament, and the human natural killer 1 antibody at midembryonic stages (Carnegie stages 16-19). During late embryonic stages (stages 20-23), a single bilobed ganglion had formed. At this time, neuropeptide Y immunoreactivity (NPY-IR) was widely expressed in sympathetic neurons (with moderate TH-IR) and chromaffin cells (with intense TH-IR). The onset of somatostatin (Som-IR) expression followed that of NPY-IR and was restricted to sympathetic neurons. However, at late embryonic stages, most TH-IR neurons with Som-IR also expressed NPY-IR (a combination of peptides not found in the mature coeliac ganglion). Between late embryonic stages and the end of the early fetal period, there was a significant increase in the proportion of neurons in lateral regions that had both NPY-IR and TH-IR. At the same time, there was an increase in the proportion of neurons in medial regions that had both Som-IR and TH-IR. Neurons expressing both Som-IR and TH-IR were rarely observed in lateral regions of the coeliac ganglion. Thus, a clear topography within the coeliac ganglion is established during late embryonic and early fetal stages of development and reflects that found in the mature animal by the end of the early fetal period.

[Embryonal development and the structure of the intermesenteric plexus in humans and various mammals]. / Embrional'noe razvitie i stroenie mezhbryzheechnogo spleteniia u cheloveka i nekotorykh mlekopitaiushchikh.

The intermesenteric plexus is an independent formation, it is connected with other plexuses in the abdominal and pelvic cavities and participates in innervation of organs. In the species investigated (mole, rat, cat, dog, man) connections between the intermesenteric and other vegetative plexuses in the abdominal and pelvic cavities vary according to their amount and complexity, they are most abundant and complex in man. In the latter the plexus is also mostly rich in neuro-fibrillar and neuro-cellular elements. In the intermesenteric plexus of the man and the animals studied there is a rather big part of vegetative ganglia, which can be considered as peripheral centers of the internal abdominal organs innervation.