Presence Of Neurons Research Articles

The effect of nerve cells on the intestinal barrier function and the influence of human milk oligosaccharides (hMOs) on the intestinal neuro-epithelial crosstalk

The intestinal epithelium is an important gatekeeper of the human body by forming a barrier for the luminal content of the intestine. The barrier function is regulated by a complex crosstalk between different cell types, including cells from the enteric nervous system (ENS). ENS is considered to influence gastrointestinal processes and functions, but its direct effect on epithelial barrier function remains to be confirmed. To investigate the effect of nerve cells on the gut barrier function, an in vitro co-culture system was established in which T84 intestinal epithelial cells and SH-SY5Y nerve cells were seeded in ratios of 29:1 and 14:1. When the epithelial barrier was disrupted with the calcium ionophores A23187, we found that nerve cells exert a protective effect on A23187-induced disruption and that this protective effect is nerve cell concentration-dependent. This was demonstrated by rescuing effects on transepithelial electrical resistance (TEER) and upregulation of tight junction (TJ) protein expression. Furthermore, we studied whether similar rescuing effects could be achieved with the human milk oligosaccharides (hMOs) 2′-fucosyllactose (2′-FL) and 3-fucosyllactose (3-FL). Our results illustrate that in the presence of nerve cells 2′-FL and 3-FL do not have any additional rescuing effects, but that these hMOs can substitute the rescuing effects of nerve cells in the absence of nerve cells. Meanwhile, 2′-FL and 3-FL show different regulation effects on TJ expression. These findings provide valuable insights into potential therapeutic strategies for maintaining intestinal barrier integrity.

Nerve cell bodies in the dorsal funiculus of the rat spinal cord

Nerve cell bodies located within the white matter of the dorsal funiculus (DF neurons) have been previously observed but not described in detail. The present study examines the morphology, ontogeny, and projection of DF neurons utilizing Fluoro-Gold as a retrograde tracer, alone, and in combination with tritiated thymidine autoradiography in the spinal cord of the rat. DF neurons were consistently labelled in spinal segments T13 through L2 following injections of Fluoro-Gold into the cerebellum. The cell bodies of DF neurons were small to medium in size, fusiform to multipolar in shape, and were located on the side ipsilateral to the injection site. Cell counts revealed approximately five labelled cells per millimeter along the longitudinal axis. An examination of neurogenesis using tritiated thymidine combined with Fluoro-Gold showed that DF neurons have relatively late birthdates as do other spinocerebellar neurons of the dorsal horn. Retrograde axon tracing studies in the spinal cord using Fluoro-Gold showed that DF neurons project rostrally via the ipsilateral lateral funiculus. The significance of the presence of nerve cells in the dorsal funiculus is unclear, but judging from their location, ontogeny, and projection, DF neurons are probably derived from the same pool of neurons as those in the Nucleus dorsalis.

Localization of dystrophin in cultures of human muscle.

Dystrophin is a protein present in normal human muscle but absent in patients with Duchenne muscular dystrophy (DMD). Using a specific antibody, we have investigated the expression of dystrophin in human muscle which had regenerated in culture in the presence of nerve cells. Dystrophin was present and was correctly localized in the cultures of normal muscle but was absent from cultures of muscle from patients with DMD. Its control and function can now be studied.

Expression of the A12 form of acetylcholinesterase by developing avian leg muscle cells in vivo and during differentiation in primary cell cultures

The accumulation of the molecular forms of acetylcholinesterase (AChE) has been studied in leg muscles during embryonic chick development and in cell cultures initiated with myoblasts obtained from embryos at different stages of development. The collagen-tailed, A(12) form appears in leg muscles as soon as day 5 in ovo. An early excision of the lumbar zone of the neural tube at day 2 1 2 in ovo severely delayed the morphological development. In leg muscles dissected at day 12 in ovo from operated embryos, we found that the total amount of AChE activity and particularly the proportion of A(12) form were dramatically reduced. Muscle cells were grown in vitro in a medium supplemented with fetal calf serum. In these conditions, chick muscle cells unequivocally synthesize the A(12) form when they originated from muscles which accumulated this form in vivo. In contrast, myoblasts obtained from 5-day old embryo leg muscles did not produce the A(12) form either in aneural cultures or in the presence of nerve cells. In relation with previous observations concerning chick myogenesis, we discuss the possibility that this difference reflects the existence of two types of myoblasts. This hypothesis would also explain the results of cocultures performed with nerve cells and normal or demedullated leg muscle myoblasts.

Ultrastructural evidence for the presence of nerve cells in the gastrodermis of Hydra.

Two types of nerve cells, namely, neurosensory and neurosecretory cells have been identified and described in the gastrodermis of Hydra pseudoligactis. The morphological criteria used for the identification of gastrodermal nerves are based on those presented previously for epidermal nerves. The third type of nerve cell in the epidermis, ganglionic cells, was not observed in these studies. The distribution, function and origin of gastrodermal nerve cells are discussed briefly.

THE CERIANTHAR1AN NERVOUS SYSTEM

Evidence supporting the presence of nerve cells in the column and tentacles of Pacliycerianthiis is described. G. F. Gwilliam has shown that electrical stimuli can be transmitted to the ectodermal muscle by the intact epithelium and subepithelial network of the ectoderm of the column. In these preparations the ectodermal muscle, mesogloea, and endoderm were cut. In contrast, preparations in which the ectodermal muscle has been left intact and the epithelium and subepithelial network cut do not show such transmission. The author and Gwilliam have independently used different silver stain methods to demonstrate large cells, piobably nerve cells, with cell bodies in the base of the epithelium and with fibers running into the subepithelial network. The author has found similar bipolar cells in the tentacles and column by using maceration techniques. These cells are compared with other cell types found in the tentacles.

On Nerve Supply of the Suprarenal Glands of Some Animals

The cortex of the suprarenal glands of dog and flying-squirrel, being an epitheliogenetic endocrine organ, was found devoid of fibres of cortical nerves proper. Of course the periaterial plexus send out nerve fibres which enter its parenchyma accompanying the blood capillaries, but these are extremely small in quantity and cannot be called nerves proper to the cortex. So, the greatest majority of the capillaries and cortical cells are free of nerve supply. Therefore, the mechanism occcasioning the secretion from this part may be interpreted as consisting in the seeping out of the secretory granules from the gland cells by pressure of dilation of the blood capillaries.In dog, the extracapsular connective tissue around the suprarenal gland is rich in fat tissue and contain extracapsular or suprarenal plexus with ganglia of varying size. In the rather thick capsule is formed the intracapsular plexus containing only a very few ganglion cells. In flying-squirrel, however, the capsule as well as the extracapsular tissue is very poorly developed, so that the plexuses in them are also very ill-developed. The ganalion cells in the dog's suprarenal plexus belong either to DOGIEL's Type I or to his Type II; their nerve processes are usually well developed.The suprarenal glands of these animals contain no ganglion cells in its medulla and in its cortex, unlike in the case of man. Therefore, it seems that the presence of nerve cells in the medulla has little functional significance.The nerve bundles or fibres originating in the extra- and intracapsular plexus, without sending out branches into the cortex, run through it into the medulla, so that these are the nerves proper to the latter. This medulla lies in the main in the central part of the suprarenal gland in flying-squirrel, but in dog it is otherwise found distributed in a manner suggestive of its embryological development. Medullar cell groups are found in the extra- and intracapsular spaces too, often keeping connect with the medulla at the center. Some medullar cells are found arranged cord-wise along the fibres of the medullar nerves proper running through the cortex.The medullar nerves proper are not rarely composed of thick fibres only, but usually thin fibres also come into the composition. These nerves proper, unlike those in man, run forth toward the center of the medulla, upon entering it, while sending out irregularly winding finer branches. The nerve fibres here seem to become the fewer, the smaller the animal in body size.Upon parting from the nerve bundles, the medullar nerve fibres run solitary courses as enormously thick fibres showing peculiar winding and perceptible change in size, while thick branch fibres of the same nature and besides many far thinner terminal fibres showing less change in size are sent out during the courses. These fibres of two types never end freely but always come into mutual anastomosis and form a large nervous network in the medulla. In this network, the thick fibres run peculiar looped or augular courses, so that the size and the shape of its meshes are much variegated, forming rectangles, polygones, rhomboids, ovals, spindle-forms and club-forms of varying size. Besides, quite nondescript meshes are also seen. The reticular formation by the thin fibres is also very peculiar, some very large-sized meshes appearing among the usual small-sized ones.The nerve fibres running in the medulla are not accompanied by SCHWNN's cells, because the medulla is composed of sympathetic chromaffin paraganglion cells originating in mother cells, the KOHN's so-called accessory cells, from which the sympathetic SCHWANN's cells are also derived, and thus can naturally dispense with SCHWANN's cells.The above-mentioned enormously thick fibres, besides coming into contact supply to the medullar cells, seem also to effect intracellular supply upon penetrating through these cells.

The Innervation of the heart of the Crustacea. I. Decapoda

The Innervation of the heart of the Crustacea. I. Decapoda