Electron-microscopic analysis of adrenergic nerve endings in the cat caudal mesenteric ganglion

The ultrastructure of nerve endings of the cat caudal mesenteric ganglion was studied after fixation of the material with 4% lithium permanganate solution by Richardson's method in the modification of Hökfelt et al. [12]. This fixation method was shown to permit the demonstration of numerous adrenergic as well as cholinergic nerve endings. Four types of adrenergic organelles were distinguished in neurons of the ganglion: small and large granular vesicles 30–50 and 70–90 nm in diameter, respectively, a tubular reticulum with electron-dense contents, and small granular vesicles 15–20 nm in diameter. The localization of the adrenergic endings and their relations with other processes and cells of the caudal mesenteric ganglion were studied in detail. The problem of the origin and physiological role of adrenergic nerve endings in this ganglion is discussed.Institute of Physiology, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 86–92, January–February, 1980.     

Immunohistochemical identification of serotonin and noradrenalin containing structures within the nerve plexuses of rat ileum

The distribution of 5-hydroxytryptamine (= serotonin = 5-HT) and noradrenalin (NA) in the enteric plexuses of the rat ileum was studied using immunocytochemical techniques. 5-HT-like immunoreactive fibers were observed only in the myenteric plexus, surrounding the ganglionic cells, which are all unreactive. NA-like immunoreactive fibers were present in all layers of the ileum: in the myenteric plexus, they were localized in the nodes, forming a network all round the neuronal perikarya; in the Meissner plexus, positive axons were arranged in a delicate network; submucosal blood vessels were often provided by NA-immunopositive nerve plexus. In the inner circular muscle layer the immunoreactive NA-positive fibers run within nerve bundles mainly parallel with the smooth muscle cells. The 5-HT immunoreactive material was depleted by treatment with reserpine; depletion of NA by 6-hydroxy-dopamine was also observed; on the contrary, no depletion of 5-HT by 5,7-dihydroxytryptamine was obtained. To confirm the validity of these results, specific antibodies to tyrosine hydroxylase (TH) and aromatic 1-aminoacid-decarboxylase (AADC), two enzymes involved in the synthesis of catecholamines, were used. In conclusion these experiments indicate that 5-HT is present, probably as a transmitter, in certain fibres of the rat myenteric plexus, distributed in a way similar to that of NA-containing fibers. However, at variance with NA fibers, 5-HT fibers are not present in other regions of the intestine wall.     

Paravascular connective tissue structures of the veins of the pelvic cavity in man

The data on structure of the paravasal connective tissue formations in some parietal pelvic veins, in the utero-vaginal plexus veins, in the fatty tissue space veins of the rectum, of the vesicular and prostatic plexuses are presented, as well as those on connections between the fascial vaginae for the veins in the human subabdominal part of the pelvis and its fascial nodes. Theoretical interpretation of gaping of the pelvic fundal venous vessels is presented. Participation of the paravasal connective tissue formations in organization of the fascial nodes of the human small pelvis is stated.     

Nerves and nerve plexuses of the human vertebral column

The origin, distribution, and termination pattern of nerves supplying the vertebral column and its associated structures have been studied in the human fetus by means of an acetylcholinesterase whole-mount method. The vertebral column is surrounded by ventral and dorsal nerve plexuses which are interconnected. The ventral nerve plexus consists of the nerve plexus associated with the anterior longitudinal ligament. This longitudinally oriented nerve plexus has a bilateral supply from many small branches of the sympathetic trunk, rami communicantes, and perivascular nerve plexuses of segmental arteries. In the thoracic region, the ventral nerve plexus also is connected to the nerve plexuses of costovertebral joints. The dorsal nerve plexus is made up of the nerve plexus associated with the posterior longitudinal ligament. This nerve plexus is more irregular and receives contributions only from the sinu-vertebral nerves. The sinu-vertebral nerves originate from the rami communicantes and, in the cervical region, also from the nerve plexus of the vertebral artery. Thick and thin sinu-vertebral nerves are found. Most frequently three types of thick sinu-vertebral nerves are observed, i.e., ascending, descending, or dichotomizing ones. Finally, the distribution of the branches of the ventral and dorsal nerve plexuses and of the sinu-vertebral nerves is described.     

Catecholamine concentration in adrenergic plexuses of the spleen and intestine during cold-induced and emotional stress

Computer analysis and histochemical techniques were used to investigate catecholamine concentration in the adrenergic plexuses of the spleen and small intestine in rats. The concentration was found to increase during both emotional and short-term cold-induced stress. Injection of 10 mg/kg guanethidine i.p. does not counteract cold-induced accumulation of catecholamines in the adrenergic plexuses of the spleen and small intestine. During emotional stress, by contrast, an accumulation of this sort does take place. The mechanisms potentially underlying catecholamine accumulation in the adrenergic plexus of these organisms associated with different types of stress are discussed. Cold-induced stress is thought to produce catecholamine synthesis in the adrenergic nerve endings of the prevertebral ganglia, whereas emotional stress leads to catecholamine uptake by adrenergic terminals from the blood.Institute of Physiology, Academy of Sciences of the Byelorussian SSR, Minsk. Translated from Neirofiziologiya, Vol. 22, No. 3, pp. 347–354, May–June, 1990.     

Pathomorphology of adrenergic and cholinergic structures of sympathetic nerve ganglia in experimental burn injuries]

Changes in adreno- and cholinergic structures of sympathetic nerve ganglia (superior cervical, stellate, and splanchnic ganglia of the solar plexus) were studied in 15 male white rats aged 5-7 months, b. m. 200-250 g, 3, 7, and 11 days after burn injury (Stages IIIA, IIIB, involving 20-25% of body surface) and in 5 reference animals. The sections were treated in 2% glyoxylic acid solution and by the Karnovsky-Roots technique. Reduced catecholamine concentrations were revealed in sympathetic nerve ganglia neurons in the early periods after burn injury; the mediator reserves are recovered to a certain measure in later periods after thermal injury. The detected shifts in the sympathetic nerve ganglia neurons correlate with the detected shifts in the cardiovascular system.     

Parasympathetic discharges evoked in the pelvic nerve by stimulation of various structures in the amygdala

Parasympathetic discharges evoked by application of single and paired stimuli to central, corticomedial, and basolateral nuclei of the amygdala were recorded from the pelvic nerve (PN) in anesthetized and immobilized cats. The discharges were found to include three main negative waves (I, II, and III waves, appearing with the latencies of 16.0–17.8, 74–87, and 171–184 msec, respectively). The first two waves were seen most regularly. Sometimes the I wave was preceded by a super-early negative component of a low amplitude appearing with a latency of 8.5–10.7 msec. The discharges evoked by stimulation of various nuclei of the amygdala did not significantly differ from each other in their thresholds, time courses, and amplitudes, which suggests a relatively diffuse distribution of parasympathetic efferent structures in the amygdala. It was shown, using paired stimuli, that a response to the second stimulus needed a long-lasting period (a few tens of milliseconds) to be restored. The origin of the components of the amygdalofugal parasympathetic discharges recorded from the PN, as well as the corresponding pathways they spread through, are discussed. In addition, the possible origin of the positive components of the PN discharges are considered.Neirofiziologiya/Neurophysiology, Vol. 26, No. 5, pp. 326–333, September–October, 1994.     

Substance-P-like immunoreactive subepithelial nerve plexuses in the labial mucosa of the mouse

Substance P (SP)-like immunoreactivity was examined in the lower labial mucosa of the mouse by using the whole-mount technique. The density and design of subepithelial nerve plexuses containing SP differed depending on portions of the lower labial mucosa.