Termination in the prevertebral abdominal sympathetic ganglia of axons arising from the local (terminal) vegetative plexus of visceral organs

Summary Degeneration of synaptic axon terminals in the prevertebral (celiac and superior mesenteric) ganglia, occurring after operative interferences on visceral organs, shows that processes of ganglion cells (probably of Dogiel type II) located in the terminal ganglia of the gallbladder and the small intestine reach and establish synapses in the prevertebral ganglia. This finding is in accordance with the persistence of delicate axons in the peripheral stumps of visceral nerves two weeks after removal of the celiac ganglion. These results speak in favour of the existence of peripheral reflex arcs in the vegetative nervous system.     

Changes in the number and volume of NPY and VIP neurons from periprostatic accessory vegetative ganglia in pre- and peripubertal rats. A stereological study

The amount of neurons of periprostatic accessory ganglia in pre- and peripubertal rats was studied to ascertain whether the development of these autonomic ganglia is androgen-dependent. Stereological estimates of the volumes and number of neurons immunoreactive to protein gene product 9.5 (PGP 9.5), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) were carried out. Immunostaining of androgen receptors (AR) in the ganglia was also performed. The ganglionic neurons from the two groups studied were immunoreactive to PGP 9.5, NPY, and VIP. Almost all the neurons were immunostained for AR. The ganglionic volume showed a significant increase in peripubertal prostate in comparison with the prepubertal gland. No significant changes were observed with respect to the absolute number of neurons immunoreactive to all the antigens. The neuronal volume was significantly increased in peripubertal rats in comparison with prepubertal animals. These findings led us to the following conclusions: There is no evidence of neurogenesis during pubertal development in the periprostatic accessory ganglia of the rat. The increase of ganglionic volume in puberty is due to the growth in neuronal volume. There were no differences between the sizes of NPY and VIP neurons in pubertal periprostatic accessory ganglia. The development of periprostatic vegetative neurons is androgen-dependent.     

Spontane vegetative bastardspaltung

Ohne Zusammenfassung     

Intercellular junctions in myriapods

Tissue from the intestinal tract of myriapods, including millipedes, centipedes and pauropods were examined in tracer-impregnated sections and freeze-fracture replicas. The foregut and hindgut of all three classes exhibit pleated septate junctions; these display undulating intercellular ribbons in thin sections. In replicas they show discrete intramembranous particle (IMP) arrays aligned in rows in parallel; with one another. The tissues of the hindgut also possess scalariform junctions, characterized by cross-striated intercellular clefts in sections and IMP-enriched membranes in replicas. Gap junctions occur in all groups, but they are atypical in replicas in that their component IMPs do not always fracture onto the E face, as is characteristic of other arthropods; some IMPs cleave to the P face and others to the E face. The midgut of these organisms exhibits smooth septate junctions with conventional straight septal ribbons and occasional interseptal columns. However the intramembranous appearance in replicas is variable, particularly in centipedes, in that the rows of IMPs in chemically-unfixed propanecryofixed tissues, are prominent and adhere preferentially to the E face, with complementary P face grooves, while in fixed tissues the IMPs are much less distinct and fracture to either P face or E face. They tend not to protrude far beyond the mid-plane of the membrane bilayer and lie in rows which commonly take on the form of a network. Individual rows of the network sometimes curve to run beside a second row, over a short distance, before bending away into another part of the network. The aligned particle rows, which are much more prominent in millipedes, where they frequently lie in close parallel appositions, do not fuse into ridges as often occurs in insect tissues. The myriapod junctions, therefore, are of the same general kind as are found in the gut tract of other arthropod groups, but differ with respect to the subtleties of their intramembranous organization and disposition.     

Sympathetic ganglia in culture

Summary The accessory cells of rat, guinea-pig and chick sympathetic ganglia have been studied in tissue culture with phase-contrast microscopy, time-lapse cinematography and fluorescence histochemistry. Small intensely fluorescent (SIF) cells have been described for the first time in culture. Satellite cells, which are closely associated with nerve cell bodies, and interstitial cells, which are dispersed throughout the ganglion, appeared to be identical cell types; they do not correspond to oligodendrocytes of the central nervous system as has been suggested previously. However, a small number of cells closely resembling central oligodendrocytes were present. Astrocyte-like cells have also been seen occasionally, although their identity is not clear. Several other cell types were present and have been identified as Schwann cells, sheath cells, fibroblasts, perineural epithelium, macrophages and endothelial cells.This work was supported by the National Heart Foundation of Australia and the Australian Research Grants Committee. We are particularly grateful to Janet McConnell for her excellent technical assistance.