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At least 19 recordsLinked to original sources
PubMed1978

[Radioautographic study of the developmental period of the cells of the supraoptic nucleus during mouse embryogenesis].

To study the time of cell origin in the supraoptic nucleus, double labelling with 3H- and 14C-thymidine was applied to the matrix cells of embryonic ependyma with intervals of 12, 24 and 48 hrs from the 9th day of gestation. The localization of the labelled cells was studied in the brain of the offspring using autoradiography. The labelling allowed to determine the time of the last division of the matrix cells, prior to their differentiation into neurosecretory cells. The neurosecretory cells forming the supraoptic nucleus were shown to arise mainly on the 11--13th day of embryogenesis. The cells originated on the 11th day were located only in the dorso-caudal parts of the nucleus. The most neurosecretory cells arise in the second half of the 12th day and are distributed all over the nucleus with the dorso-ventral (caudo-rostral) gradient. From the 13th day on the migration of the neurosecretory cells in the supraoptic nucleus sharply reduces but still persits until the 17th day. The glioblasts begin to migrate in the supraoptic nucleus from the 14th day on.

Animals↗
PubMed1978

Neurones with synchronous bursting discharges in organ cultures of the hypothalamic supraoptic nucleus area.

Explants of the hypothalamic supraoptic nucleus area from newborn rats were cultured. Ultrastructural studies revealed the existence of typical neurosecretory granules in neuronal perikarya as well as in axons. Large nerve cells that were spontaneously active discharged at an average firing rate of 7.2 +/- 4.4 (S.D., n = 98) spikes/sec and 42% of these neurones displayed a phasic firing pattern as shown by the existence of peaks in their autocorrelograms. The firing of 59% of the neurones was synchronous with the activity of other nerve cells. In some neurones, only the onsets of bursts were correlated, whereas in others periods of high correlation alternated with periods of no correlation. The relative proportion of rhythmically or synchronously firing hypothalamic neurones was not altered when a neurohypophysial explant was co-cultured. Field stimulation in the cultures resulted in a short-latency excitation followed by an inhibition which was found to be bicuculline-sensitive. The existence of functional synapses was furthermore demonstrated by intracellular recordings of postsynaptic potentials.

Action Potentials↗
PubMed1979

Cytoarchitecture of the supraoptic nucleus. A Golgi study.

A Golgi-Cox study of the supraoptic nucleus of the adult rabbit has revealed the presence of three major cell types: (1) large multipolar neurons; (2) large bipolar neurons, and (3) small interneurons. The multipolar and bipolar neurons demonstrated regional variation in the rostral and caudal aspects of this nucleus, while the interneurons appeared identical throughout the nucleus. This study provides detailed cytoarchitectural descriptions of the magnocellular neurosecretory cells in the supraoptic nucleus and establishes the presence of an interneuronal cell population through which incoming afferent messages could influence the neurosecretory neurons.

Animals↗
PubMed1976

The supraoptic nucleus and the supraopticohypophysial tract in the monkey (Macaca mulatta).

The observations here on Golgi material are based on the study of fortunate impregnations in one horizontally sectioned and one frontally sectioned series found in the collection of Golgi preparations of the adult monkey brains (Macaca mulatta) available in this laboratory. The soma of the large supraoptic neurons have jagged protrusions and irregular crevices which give their surfaces a craggy appearance. Also they have a few somatic spines. Their dendrites, which usually arise from two or three dendritic trunks, emerging from the cell body, are moderately branched and have occasional dendritic spines. The axon emerges from a conical elevation either on the soma or a dendrite and is directed towards the supraopticohypophysial tract. In the present material there are a few neurons of the supraoptic nucleus impregnated that are definitely smaller than the larger neurons. They have short beaded axons, ending in the supraoptic nucleus a short distance from their point of origin. In the horizontal sections the supraopticohypophysial tract fibers can be seen passing over the posterior aspect of the optic tract. In the frontal sections, this fan-shaped tract, wide above and constricted below, can be followed into the median eminence. Some of these axons in their intrahypothalamic course have short beaded collaterals. Electron micrographs reveal: (1) endings with spherical synaptic vesicles and endings with flattened synaptic vesicles synapsing on neurosecretory axons in the supraoptic nucleus; (2) a few myelinated fibers containing neurosecretory granules in the intrahypothalamic portion of the supraopticohypophysial tract. As can be seen in both Golgi and electron microscopic preparations the presence of fibrous astrocytes in the supraoptic nucleus and their abundance in the hypothalamic portion of the supraopticohypophysial tract is characteristic of this neurosecretory system. In the nucleus and in the tract processes of the fibrous astrocytes are intimately associated with neurosecretory fibers.

Animals↗
PubMed1977

Characterization of the responses of oxytocin- and vasopressin-secreting neurones in the supraoptic nucleus to osmotic stimulation.

1. Extracellular action potentials were recorded from forty antidromically identified single units in the supraoptic nucleus of lactating, urethane-anaesthetized female rats. The activity was monitored both during reflex milk ejection and during an increase of 10-15 m-osmole/kg in plasma osmotic pressure induced by intraperitoneal injection of 1 ml. of 1.5 M-NaCl solution.2. About half (eighteen) the cells showed a burst of activity before reflex milk ejection and were dubbed oxytocin cells. Oxytocin cells responded to a hypertonic injection with a smooth sustained threefold increase in firing rate.3. The remainder (twenty-two) showed no burst of activity before reflex milk ejection and were dubbed vasopressin cells. Vasopressin cells doubled their firing rate as plasma osmotic pressure increased. Neither cell type increased its firing rate after injections of isotonic NaCl.4. A phasic firing pattern was rarely seen in slow firing vasopressin cells (< 2 spikes/sec) but was seen in almost all vasopressin cells (twelve out of fourteen) firing between 3 and 8 spikes/sec. Above 8 spikes/sec, some vasopressin cells fired continuously. Phasic firing was only once encountered in an oxytocin cell.5. The firing rate of both oxytocin and vasopressin cells decreased when plasma osmotic pressure was reduced 10-15 m-osmole/kg by an intragastric water load of 10 ml.6. Hypothalamic cells lying just outside the supraoptic nucleus did not show a consistent response to injection of hypertonic NaCl.7. Clearly, both oxytocin and vasopressin cells are osmoresponsive, but phasic firing is characteristic of stimulated vasopressin cells. Thus, osmotic activation allows discrimination between oxytocin- and vasopressin-secreting neurones.

Action Potentials↗
PubMed1979

[Role of adrenergic innervation in the regulation of the secretory activity of supraoptic nucleus cells in rats].

6-hydroxydopamine (6-HD), producing specific destruction of noradrenergic (NA) terminals, was used to study the role of NA innervation in the production of peptide neurohormones by the supraoptic nucleus (SON) cells. Seven days after intraventricular administration of 6-HD in a dose of 250 micrograms the fluorescence intensity of NA terminals in SON area was highly decreased and morphological pictures, reflecting the activation of hormone production in SON cells, were observed. According to the data obtained NA innervation is likely to inhibit the peptide neurohormone synthesis by SON cells and to regulate the transport and release of peptide neurohormones from the posterior pituitary into general circulation.

Animals↗
PubMed1977

[Effect of anticholinesterase agents on the protein and RNA content in the cells of the supraoptic nucleus during sleep and its disorder].

In rats, administration of anticholinesterase drugs (both the penetrating blood-brain barrier armin and the nonpenetrating preparation Gd-42) prevented the decrease of protein content in the neurons and glia of the supraoptic nucleus, as well as of RNA content in the neurons which usually occurred in intact animals after 24-hr deprivation of the REM sleep by the Jouvet method (also with partial disturbance of the slow wave phase).

Animals↗
PubMed1977

Neuronal cytoplasmic inclusions in the dorsal horn and supraoptic nucleus of the squirrel monkey, Saimiri sciureus.

In the squirrel monkey (Saimiri sciureus) two types of cytoplasmic inclusion bodies have been observed sporadically in neurons of both the dorsal horn (Rexed's laminae I-III in the lumbosacral region) and the supraoptic nucleus. One of these, designated here the "vesicular body", is a round inclusion which measures up to 1.4 mu in diameter. It occurs only in perikarya and is composed of vesicular-like chambers 300-400 A in diameter. We have not found previous references to this structure in the literature, but its 50 A substructural particles are similar in size to those described in nematosomes. The other inclusion, a "filamentous whorl", is found in nerve cell bodies and dendrites and it is structurally similar to the Hirano body. The structure measures up to 2.2 mu in diameter and is composed of circularly arrayed filaments which vary in configuration and size depending on the plane of section. There are no indications that the vesicular body and the filamentous whorl are in any way related to each other; and usually both are not found in the same cell profiles.

Animals↗
PubMed1976

[Ultrastructural changes in the supraoptic nucleus and posterior lobe of the pituitary following experimental burns].

The dynamics of the ultrastructure of the neurosecretory system in the postburn period is characterized by phasic of organells of neurosecretory cells and synapses on their bodies and processes. Immediately after burn there appear pronounced signs of an increased formation of secretion synchronous to a considerably increased functional activity of synaptic structures. Of the opposite character are fine structures in neurocytes in the subsequent period (1-1,5 hour after burn). Phenomena of disintegration and degeneration of organells are developing in the cells. In the posiologically active neurohormones and degeneration of membrane structures gradually increase at all the observed stages of the burn trauma. All the elements of the supraoptic nucleus and the posterior lobe of the hypophysis early responding to the effect of such a powerful extreme factor are involved in the response of the organism to burn. It should be noted that immediately after burn there appears an increased permeability of capillaries followed by extravasation of formed elements and liquid blood. It steadily increases with the development of the process.

Animals↗
PubMed1977

[Changes in the accessory group of hypothalamic neurosecretory cells following stimulation of the supraoptic nucleus].

Changes of an accessory neurosecretory cell group were investigated in acute experiments on cats under chloralose anesthesia. The unilateral stimulation of the supraoptic nuclei (with vasoconstrictory effect) caused activation of cells of the accessory group at the side of stimulation, and increase of the nucleolar size. No changes in the paraventricular nuclei were observed, whereas cells of the supraoptic nuclei were activated. The identity of the main and the accessory neurosecretory group reaction and literature data on histochemistry suggest that both cell groups produced vasopressin stored in the posterior lobe of the hypophysis, and acted partially as a mediator outside the hypothalamus.

Animals↗
PubMed1978

Immunocytochemical study of the hypothalamo-neurohypophysial system. IV. Topographical distribution of neurophysin neurons of the sheep paraventricular and supraoptic nucleus.

An antiserum cross-reactive against ovine neurophysins-I-II and -III has been used in conjunction with the immunoperoxidase histochemical procedure to localize the cells of the sheep paraventricular (PVN) and supraoptic nuclei (SON). In order to describe the topographical distribution of the SON and PVN a study was made on the serial sections cut (a) transversely from rostral to caudal positions and (b) sagittally from lateral to medial positions of the hypothalamus. The cells of the SON, when examined in the transverse aspect, extended approximately 1900 mu caudally and when examined in the sagittal plane were contained within a lateral-medial distance of 4830 mu. In each case the SON cells lay adjacent to the optic chiasm. As sections were cut transversely, the cells of the PVN first appeared in a rostral position defined as 0mu and close to the ventral lining of the third ventricle. This general ventral and ventro-lateral distribution of cells maintained up to a caudal distance of approximately 840 mu. From positions 1260-2310mu there was a dramatic dorsal shift of the PVN cells which by this time had also extended laterally. The total rostral-caudal distance occupied by the PVN cells was 3150mu. That the lateral-medial distance occupied by the PVN was small (1050mu) was determined on examining the magnocellular nuclei in sagittal section.

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