Microfluorimetric study of adrenergic structures in nerve plexuses of the cat pelvic cavity following decentralization and in the normal

Microfluorimetric techniques were used to investigate catecholamine concentration in small, intensely fluorescent cells and adrenergic fibers of the cat pelvic plexus ganglia and intramural ganglia of the urinary bladder and rectum in the control and following sympathetic and parasympathetic denervation. The cells examined could be divided between catecholamine- and serotonin-containing types. Parasympathetic denervation brought about an increase in the number of cells displaying serotinergic fluorescence and heightened fluorescence in the adrenergic fibers of the pelvic plexus ganglia and intramural ganglia of the urinary bladder, without affecting degree of fluorescence in those of the rectal intramural ganglia. Sympathetic denervation failed to change fluorescence level in the cells and adrenergic fibers in pelvic plexus and urinary bladder ganglia but caused the almost complete disappearance of the adrenergic fibers in the rectal intramural ganglia.Institute of Physiology, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Neirofiziologiya, Vol. 18, No. 4, pp. 496–502, July–August, 1986.     

Intramural neurons in the urinary bladder of the guinea-pig

Summary The urinary bladder of adult female guinea-pigs was stained histochemically to detect the presence of intramural ganglion neurons. Counts on wholemount preparations of entire bladders revealed the presence of 2000–2500 neurons per bladder, either as individual nerve cells or, more often, as ganglia containing up to 40 neurons. Both ganglia and single neurons lie along nerve trunks and are interconnected to form a plexus. Ganglia occur in every part of the bladder; they are more numerous on the dorsal than on the ventral wall, and they are especially abundant in an area within a radius of 800 m from the point of entry into the bladder wall of ureters and urinary arteries. The ganglia are located inside the muscle coat and close to muscle bundles; they usually lie nearer the mucosa than the serosa. Ultrastructurally, each ganglion is surrounded by a capsule; in addition to neurons and glial cells, the ganglia contain capillaries, collagen fibrils and fibroblasts; ganglion neurons are individually wrapped by glial cells and are separated from one another by connective tissue.     

Conducting pathways of the dog solar plexus

Conducting pathways of the dog solar plexus were studied by recording action potentials from its nerves. The splanchnic nerves are composed of two groups of fast-conducting afferent A fibers (with conduction velocities of 12–15 and 25–56 m/sec), slowly conducting afferent C fibers (0.4–2.0 m/sec), and preganglionic B and C fibers (1.0–12.0 m/sec). Afferent A and C fibers from peripheral nerves run without interruption through the ganglia of the solar plexus, splanchnic nerves, and sympathetic chain and they enter the spinal cord in the composition of the dorsal roots. Cell bodies of A fibers are located in the spinal ganglia, those of the C fibers below the ganglia of the solar plexus, evidently in the walls of the internal organs. Peripheral nerves contain A fibers only with very low conduction velocities (13–20 m/sec) and no fast-conducting A fibers (25–56 m/sec) were found. Preganglionic fibers terminate synaptically on neurons of the ganglia of the solar plexus whose axons run in the peripheral nerves to the internal organs. Synaptic pathways run from some peripheral nerves of the solar plexus into others through its ganglia; in all probability these pathways participate in peripheral reflex arcs.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 8, No. 1, pp. 76–83, January–February, 1976.     

Distribution and projections of neurons with immunoreactivity for both gastrin-releasing peptide and bombesin in the guinea-pig small intestine

Summary Bombesin-like and gastrin-releasing peptide (GRP)-like immunoreactivities were localized in nerves of the guinea-pig small intestine and celiac ganglion with the use of antibodies raised against the synthetic peptides. The anti-bombesin serum (preincubated to avoid cross reactivity with substance P) and the anti-GRP serum revealed the same population of neurons. Preincubation of the antibombesin serum with bombesin abolished the immunoreactivity in nerves while absorption of the anti-GRP serum with either bombesin or the 14–27 C-terminal of GRP only reduced the immunoreactivity. The immunoreactivity was abolished by incubation with GRP 1–27.Immunoreactive nerves were found in the myenteric plexus, circular muscle, submucous plexus and in the celiac ganglion. Faintly reactive nerve cell bodies were found in the myenteric ganglia (3.2% of all neurons) but not in submucous ganglia. After all ascending and descending pathways in the myenteric plexus had been cut, reactive terminals disappeared in the myenteric plexus, circular muscle (including the deep muscular plexus) and the submucous plexus on the anal side. After the mesenteric nerves were cut no changes were observed in the intestinal wall but the reactive fibres in celiac ganglia disappeared. It is deduced that GRP/bombesin-immunoreactive nerve cell bodies in myenteric ganglia project from the myenteric plexus to other myenteric ganglia situated further anally (average length 12 mm), anally to the circular muscle (average length 9 mm), anally to submucous ganglia (average length 13 mm) and external to the intestine to the celiac ganglia.It is concluded that the GRP/bombesin-reactive neurons in the intestinal wall represent a distinct population of enteric neurons likely to be involved in controlling motility and in the coordination of other intestinal functions.     

The distribution of noradrenergic nerves and small,intensely fluorescent (SIF) cells in the cat urinary bladder

Summary Fluorescence and electron microscopy have been used to study the distribution of noradrenergic nerves in the smooth muscle of the cat urinary bladder. Using the former technique, relatively few fluorescent noradrenergic nerves were observed in the body and fundus, while a rich plexus occurred adjacent to muscle cells of the bladder neck. The trigone could not be distinguished neuromorphologically from detrusor muscle in this region. Electron microscopy showed that the majority of noradrenergic terminals in the body and fundus were associated with presumptive cholinergic axons, while in the bladder neck noradrenergic terminals formed typical neuroeffector relationships with individual smooth muscle cells.Numerous ganglia occurred both in the adventitia and among the smooth muscle bundles, particularly in the bladder neck. The majority of the nerve cell bodies were non-fluorescent, although many contained bright orange autofluorescent granules, believed to be lysosomes. A small minority of ganglion cells were associated with fluorescent noradrenergic nerve terminals, thereby providing structural evidence for limited intraganglionic inhibition. In addition, occasional groups of small intensely fluorescent (SIF) cells were observed in some intramural ganglia and these were subsequently identified in the electron microscope. The possibility that these cells may provide a second inhibitory influence on bladder activity was considered.     

Histo- and immunocytochemical characterization of the neurons of the mucosal plexus in the rat colon.

The mucosal plexus of the rat colon descendens is constituted of a network of nerves that, in contrast to most other segments of the digestive tract, contains also ganglia. The ganglia, consisting of neurons and glial cells, are located in the basal part of the lamina propria at distances between 100 and 1,200 microns. They are not vascularized. The neurons in these ganglia were characterized by means of: (1) the histochemical demonstration of acetylcholinesterase (AChE) activity, (2) the immunocytochemical identification of neurofilament proteins (NFP; 200 kD) and (3) their ultrastructure. The glial cells, which were AChE negative, could be distinguished from the neurons by differences in size and chromatin pattern. All neurons of the mucosal plexus reveal AChE activity in the perikaryon, but only parts of the axons are AChE positive. NFP-like immunoreactivity was detected in the perikarya but only in a minor part of the axons. These findings confirm previous light-microscopical observations and add new evidence for the existence of neurons (ganglia) in the mucosal plexus of the rat colon.     

Location of bodies of peripheral (sympathetic) afferent neurons participating in peripheral reflexes of the small intestine

Acute electrophysiological experiments on cats have shown that after preliminary decentralization of the solar plexus, accompanied by degeneration of spinal and vagal afferent and preganglionic efferent fibers in its postganglionic (mesenteric) nerves, only slow activity of the C-afferents is recorded in the peripheral segments of the mesenteric nerves instead of activity of the A-, B-, and C-fibers in the control (before degeneration). Activity of the C-afferents is intensified with the appearance of spontaneous contractions of the small intestine and also after gentle stretching of the corresponding segment of the intestine by inflation of a rubber balloon. After preliminary division of the mesenteric nerves, accompanied by degeneration of the postganglionic fibers in their peripheral segments, activity of C-afferents only also was observed, but it was much weaker than in the first series of experiments. After preliminary decentralization of the solar plexus and division of the mesenteric nerves application of a single electrical stimulus to the central part of one of the divided mesenteric nerves evokes a reflex electrical response in the other mesenteric nerves which disappears after treatment of the ganglia of the solar plexus with azamethonium bromide and also after electrical stimulation of the mesenteric nerves at 10–20 Hz. However, after decentralization only, this response was much weaker than after division of the mesenteric nerves. It is concluded that these peripheral responses of the intestinal nerves are due to excitation of two types of peripheral afferent neurons: the bodies of some lie in the small intestine and their long axons (C-afferents) run to the ganglia of the solar plexus; the bodies of the others lie in the ganglia of the solar plexus and their long axons (also C-afferents) run to the intestine, where they terminate in its receptors.Institute of Physiology, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Neirofiziologiya, Vol. 6, No. 2, pp. 175–185, March–April, 1974.     

Intramural ganglia of the human gallbladder: morphological and functional observations]

The purpose of this study was the reinvestigation of the intrinsic innervation of human gall bladder with an immunohistochemical technique named peroxidase anti-peroxidase (PAP). The antigen demonstrated was the S100 protein normally present in the surface of glial cells, Schwann cells and satellite cells in ganglia. The tissues used were taken from 20 human gall bladders, fixed after surgery. This technique is not specific to demonstrate adrenergic or cholinergic innervation but it reveals just myelinated fibers. The current study was undertaken in order to study the organization and the function of plexus of nerves and ganglia present in the wall of the gall bladder. The neck of the gall bladder was the region in which the higher number of nerve cells and nervous fibers was present. The technique used has demonstrated ganglionated plexus and nerves in submucosal layer, fibromuscular and adventitial layer according to the enteric nervous system. All ganglia are postganglionic stations related with preganglionic cholinergic fibers. These results confirm that the intramural ganglia of the gall bladder are analogous to those of the enteric nervous system according to their common origin.     

Partial urethral obstruction enhances NADPH-diaphorase activity in the monkey (Macaca fascicularis) bladder: light and electron microscopic studies

The effect of partially obstructing the urethra on the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity in neurons of the intramural ganglia of the monkey (Macaca fascicularis) bladder was examined by light and electron microscopy. Partial urethral ligation was done in adult male monkeys. The animals were sacrificed 2, 4 weeks after partial urethral obstruction. This was compared to controls (normal and sham operated). Urethral obstructed animals were observed to have increased urinary frequency and decreased urinary flow rate. Two weeks after urethral obstruction, the overall NADPH-d activity in the intramural ganglia of the bladder base was enhanced compared to control animals. The frequency of intensely stained NADPH-d positive neurons was increased compared to the control animals. About one-third of intensely stained NADPH-d positive neurons appeared to undergo degenerative changes. At 4 weeks after urethral obstruction, a wide occurrence of NADPH-d positive neurons in advanced stages of degeneration in the bladder base was observed. Cellular debris was strewn among normal looking ganglion cells and along the nerve processes. The proportion of intensely stained NADPH-d positive neurons was relatively lower than the controls. The total number of NADPH-d positive neurons and the nerve fibres in the entire bladder was significantly reduced when compared to control animals. Electron microscopy showed some NADPH-d activity in intramural ganglion cells in 2 weeks after partial urethral obstruction. NADPH-d reaction product (formazan) was deposited on the membranes of the rough endoplasmic reticulum, and the outer membranes of some mitochondria in the intramural neuron. At 4 weeks after urethral obstruction, NADPH-d was present in the membrane of the mitochondria and some mitochondria appeared swollen with disrupted cristae. Present results show that NADPH-d activity in neurons of the intramural ganglia of the monkey (Macaca fascicularis) urinary bladder was increased after two weeks and reduced after 4 weeks of partial urethral obstruction. It is speculated that the increased NADPH-d activity associated with partial urethral obstruction would lead to neuronal damage and death, which may contribute to detrusor overactivity. However, it warrants further investigation to understand the mechanism of neuronal cell death after partial urethral obstruction.     

Structure and functional changes in the gastric intramural nervous plexus in emotionally stressed rats exposed to low doses of long-term ionizing irradiation and lead

Changes in the catecholamine content in adrenergic fibres, acetylcholinesterase activity, and in the energy metabolism enzymes lactate dehydrogenase and succinate dehydrogenase in neurons of the gastric intramural plexus during emotional stress in rats a day after combined exposure to prolonged (30 days) ionizing radiation in a total dose 1.0 Gy and 0.6 mg/kg lead were studied. A decrease in catecholamines in adrenergic fibres and acetylcholinesterase and lactate dehydrogenase activity in neurons was observed. An enhanced sensitivity of the gastric intramural plexus after the prolonged exposure to small doses of ionizing radiation and lead in conditions of emotional stress was suggested.     

Cholinergic innervation of the gastric wall of the cat.

The inbuilt intrinsic cholinergic nervous apparatus of the gastric wall of the cat was studied by using two thiocholine methods for mapping the acetylcholinesterase-positive nerves and nerve cells. A rich distribution of acetylcholinesterase-positive nerves was observed in all layers of the gastric wall, except the superficial half of the lamina propria (with the epithelium), which was completely devoid of acetylcholinesterase activity, and the submucosa, in which a scarce distribution of large nerve fascicles and nerve trunks was observed. Acetylcholinesterase-positive ganglia were observed both in the subserous layer and in the myenteric plexus of Auerbach, whereas none were recognized in the submucous plexus of Meissner. This obviously fits well to the results of some electrophysiological experiments which indicate that the submucous plexus of Meissner includes an important intramural pathway from the extrinsic vagus nerves to the antrum region; so the submucous plexus of Meissner seems to be mainly involved in direct rapid conduction of nerve impulses without integrative activities, like a cable. Certain clear differences exist in the pattern of organization of the cholinergic intrinsic nervous apparatus within the different layers of the gastric wall in the fundic and pyloric regions. These differences seem to correspond quite logically to the different types of motor, secretory and neurohumoral activities of these main regions of the stomach. The activity of the non-specific cholinesterases was localized both in the neural elements and the smooth muscle, as well as in some epithelial cells.     

Distribution and changes with age of nitric oxide synthase-immunoreactive nerves of the rat urinary bladder, ureter and in lumbosacral sensory neurons

In the distal parts of the urinary tract, nerves containing nitric oxide (NO) are either postganglionic parasympathetic nerves, with cell bodies in the major pelvic ganglia, or sensory nerves with cell bodies in the lumbosacral dorsal root ganglia. We have used indirect immunohistochemical techniques to examine the distribution and regional variation of nerves immunoreactive for neuronal nitric oxide synthase (NOS) in the urinary bladder, distal ureter and in neurons in lumbosacral dorsal root ganglia (L1-L2 & L6-S1) of young adult (3 months) and aged (24 months) male rats. Semi-quantitative estimations of nerve densities were made of NOS fibres innervating the dome, body and base of the urinary bladder and distal ureter. Quantitative studies were also used to examine the effects of age on the percentage of dorsal root ganglion neurons immunoreactive for NOS. The dome and the body regions, in both age groups, contained no NOS-immunoreactive axons. The bladder base and distal ureter in young adults showed sparse to moderate numbers of fibres immunoreactive to NOS within the urothelium and in the subepithelium and muscle coat. In the aged rat there were slight reductions in the densities of NOS-immunoreactive nerves in all three regions. In the lumbosacral dorsal root ganglia, the percentage of NOS-immunoreactive neuronal profiles showed a significant reduction from 4.6 +/- 0.2% in young adult to 2.7 +/- 0.2% (means +/- S.E.M) in aged rats. These findings suggest that the effects of NO on the bladder and distal ureteric musculature and also its expression in dorsal root ganglion neurons are affected in aged rats and that the micturition reflex may be perturbed as a result.     

Conducting pathways of the rabbit lumbar sympathetic ganglia

Conducting pathways of ganglia from the lumbar portion (L₃–L₅) of the sympathetic trunk in rabbits were studied by recording action potentials from nerves of the ganglia evoked by stimulation of other nerves of these ganglia, and by intracellular recording from single neurons. Besides the well-known system of descending preganglionic fibers, which enter the trunk through white rami communicantes and, as they pass through the ganglia, form synapses on ganglionic neurons, some preganglionic fibers were shown to enter the sympathetic chain through gray rami communicantes and to run in both ascending and descending directions, forming synaptic connections with neurons of the lumbar ganglia.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 16, No. 2, pp. 247–254, March–April, 1984.     

Localisation and measurement of VIP in the genitourinary system of man and animals

VIP is present in the genitourinary system of man and animals. In man the highest concentrations are found in the penis, the uterus and vagina and in the urinary bladder. VIP nerves heavily innervate the erectile tissue of the male external genitalia, the uterine smooth muscle and blood vessels, the seromucous glands of the cervix, and the lamina propria and vaginal epithelium. In the urinary bladder, VIP nerves are located beneath the transitional epithelium, in the lamina propria and in the smooth muscle. Other areas well innervated by VIP nerves include the prostate, seminal vesicles and vasa deferentia. Chemical (phenol- and 6-OHDA) or surgical (hypogastric or pelvic nerve section) extrinsic denervation fail to deplete the genitourinary system of its VIP content, supporting the view that VIP-containing nerves originate from local ganglion cells. Indeed, neuronal cell bodies containing VIP are seen in the paracervical ganglia of the female genitalia, the para- or intramural bladder ganglia and scattered through the base of the cavernosum body, the neck of the bladder and the prostate. The finding of elevated levels of VIP in the local circulation after induced penile erection in man and mammals and the ability of VIP to relax the detrusor muscle of the bladder suggests that the peptide may be involved in penile erection and bladder relaxation, as does the marked VIP depletion in the penis or bladder in patients suffering from diabetic impotence or bladder instability.     

Distribution and changes with age of calcitonin gene-related peptide- and substance P-immunoreactive nerves of the rat urinary bladder and lumbosacral sensory neurons

In the distal parts of the urinary tract, nerves containing calcitonin gene-related peptide (CGRP) or substance P (SP) are sensory with their cell bodies located in lumbosacral dorsal root ganglia. These two neuropeptides are recognised as being present in pelvic sensory nerves, and may be involved in the mediation of pain, stretch and/or vasodilatation. We have used indirect immunohistochemical techniques to examine the distribution and regional variation of nerves immunoreactive (-ir) for CGRP and SP in the urinary bladder and in neurons in lumbosacral dorsal root ganglia (L1-L2 & L6-S1) of young adult (3 months) and aged (24 months) male rats. Semi-quantitative estimations of nerve densities were made for CGRP-ir and SP-ir fibres innervating the dome, body and base of the urinary bladder. Quantitative studies were also used to examine the effects of age on the percentage of dorsal root ganglion neurons immunoreactive for CGRP and SP. There were very few immunoreactive axons in the dome and the overall density of innervation increased progressively towards the base of the bladder. The density of innervation in the aged rats revealed a slight reduction in CGRP and SP innervation of the detrusor muscle but was otherwise comparable to the young group. However, immunostaining of the lumbosacral dorsal root ganglia revealed that the percentage of CGRP- and SP-ir neuronal profiles showed a significant (P < 0.05) reduction from (mean +/- S.D) 44.5 +/- 2; 23.3 +/- 2 in young adult to 25.0 +/- 2.9; 14.8 +/- 1.6 in aged rats, respectively. These findings suggest that the involvement of CGRP and SP in urinary bladder innervation is relatively unchanged in old age, but their expression in dorsal root ganglion neurons is affected by age. The afferent micturition pathway from the pelvic region via these lumbosacral ganglia may be perturbed as a result.     

Neuropeptide Y-like immunoreactivity in intramural ganglia of the newborn guinea pig urinary bladder

Immunoreactive neuropeptide Y (NPY) was demonstrated in neuronal elements in the urinary bladder wall of the newborn guinea pig. Numerous intramural ganglia were found lying among the smooth muscle bundles and in the submucosa, and NPY-like immunoreactive nerve cell bodies were demonstrated within all of these ganglia. Nerve fibres containing NPY were also richly distributed in the detrusor muscle, submucosa and around blood vessels. In dissociated cell cultures from newborn guinea pig detrusor muscle, a subpopulation (70-85%) of both mononucleate and binucleate intramural neurones was shown to contain NPY-like immunoreactivity. A low percentage (1-6%) of the intramural bladder neurones contained dopamine-beta-hydroxylase. In conclusion, while some NPY-containing nerve fibres in the wall of the bladder are of sympathetic origin, especially those supplying blood vessels, the results of this present study establish that many of these NPY-containing nerve fibres originate from non-adrenergic cell bodies within the intramural bladder ganglia.     

Peptide-containing nerves in the urinary bladder of the toad,Bufo marinus

The distributions of peptide-containing nerves in the urinary bladder of the toad, Bufo marinus, were studied by means of fluorescence immunohistochemistry of whole-mount preparations. The bundles of smooth muscle in the bladder are well supplied by varicose nerve fibres displaying somatostatin-like immunoreactivity; these fibres probably arise from intrinsic perikarya. The urinary bladder also has a well-developed plexus of nerves containing substance P-like immunoreactive material; these elements probably represent sensory nerves of extrinsic origin. Nerve fibres showing immunoreactivity to vasoactive intestinal polypeptide (VIP) or enkephalin are rare within the urinary bladder of the toad. It is considered unlikely that any of these peptides directly mediates the hyoscine-resistant excitatory response of the smooth muscle to nerve stimulation in the toad bladder.     

Cholinergic neurons of the pelvic autonomic ganglia and uterus of the female rat: distribution of axons and presence of muscarinic receptors

Acetylcholine (ACh) stimulates contraction of the uterus and dilates the uterine arterial supply. Uterine cholinergic nerves arise from the paracervical ganglia and were, in the past, characterized based on acetylcholinesterase (AChE) histochemistry. However, the histochemical reaction for acetylcholinesterase provides only indirect evidence of acetylcholine location and is a nonspecific marker for cholinergic nerves. The present study: (1) reevaluated cholinergic neurons of the paracervical ganglia, (2) examined the cholinergic innervation of the uterus by using retrograde axonal tracing and antibodies against molecules specific to cholinergic neurons, choline acetyltransferase and the vesicular acetylcholine transporter, and (3) examined muscarinic receptors in the paracervical ganglia using autoradiography and a radiolabeled agonist. Most ganglionic neurons were choline acetyltransferase- and vesicular acetylcholine transporter-immunoreactive and were apposed by choline acetyltransferase/vesicular acetylcholine transporter-immunoreactive terminals. Retrograde tracing showed that some cholinergic neurons projected axons to the uterus. These nerves formed moderately dense plexuses in the myometrium, cervical smooth muscle and microarterial system of the uterine horns and cervix. Finally, the paracervical ganglia contain muscarinic receptors. These results clearly reveal the cholinergic innervation of the uterus and cervix, a source of these nerves, and demonstrate the muscarinic receptor content of the paracervical ganglia. Cholinergic nerves could play significant roles in the control of uterine myometrium and vasculature.     

Vascularization of the myenteric plexus in the small intestine of pigeons]

By means of light and electron microscopy vascularization of the myenteric plexus has been studied in the pigeon small intestine. Ganglia of the plexus, their cell composition, ultrastructure of neurons have been described. Links of the microcirculatory bed of the intramural ganglia are characterized, interrelations of capillaries with neurons are described, quantitative estimation of microhemovessels, surrounding the microcirculatory bed of the myenteric plexus in the intestinal wall in birds and mammalia.