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Biomedical subjects

D Fellmann

Publications and source records attributed to D Fellmann.

At least 109 records · Page 6Linked to original sources

[Comparative immunocytochemical study of the neuroglandular hypothalamic CRF system in the postnatal period in dogs and cats].

Immunocytochemical visualization, and comparative morphological analysis of the paraventriculo-infundibular CRF-positive system was performed in new-born dogs and young cats. Our studies underline the identity of this system and its structural similarity among Mammals. They confirm the interspecificity of the antigenic sites recognized by our ovine CRF-antibodies.

Aging↗

[Human ontogeny of the hypothalamic neuroglandular system immunoreactive to an anti-hpGRF 44 immune serum].

An hypothalamo-infundibular neuroglandular system stained by an anti-hpGRF 44 serum is described in human brain. Perikarya are located in the infundibular nucleus, and their fibres end in posterior and lateral territories of the zona externa of the Median Eminence . Somatostatin fibres, morphologically different, also end in the same areas. Fibres giving intra- eminential terminals, so as hypothalamic perikarya are revealed as early as the 18 th week of fetal life.

Adult↗

[Demonstration of a neuronal peptide system reactive with anti-CRF41 immune serum, in fresh water and marine teleosts].

CRF41 antibodies stained a peptidergic neurone system in the brain of several species of Teleost Fish. Perikarya are localized in the preoptic nucleus. Processes terminate mainly in the neurodigitations of the proadenohypophysis, close to corticotrophs. There are fewer ending in the neural lobe in contact with pars intermedia cells. CRF +/- nerve profiles and perisomatal endings were also observed in various brain areas.

Animals↗

Immunocytochemical demonstration of corticoliberin-like immunoreactivity (CLI) in neurones of the rat amygdala central nucleus (ACN).

Anti-corticotropin-releasing factor (CRF) antibodies revealed numerous perikarya in the amygdala central nucleus (ACN) of colchicine-injected rats. Most of the immunoreactive processes emerging from these neurone bodies seemed to project to the lateral hypothalamus by the ventral amygdalo-hypothalamic pathway. As well as parvocellular areas of the hypothalamic paraventricular nucleus where numerous neurones containing corticoliberin-like immunoreactivity (CLI) were demonstrated, ACN is densely innervated by beta-endorphin fibres originating from pro-opiomelanocortin neurones of the hypothalamic arcuate nucleus. The facilitatory influences of the amygdala on the corticotropic axis are most probably mediated by the ACN CLI neurones, the possible infundibular projections of which remain to be demonstrated.

Amygdala↗

[Immunocytochemical study of the ontogenesis of the CRF-containing neuroglandular system in the rat (author's transl)].

In the Rat, immunoreactive CRF-containing processes appear in the median eminence between the 18 and the 19th day of the fetal development. They seem to become functional as early as the 19th day since they establish neuro-hemal junctions with the capillaries of the Mantel Plexus. During the pre- and post-natal periods, the number of these fibers increases greatly in the median eminence where they extend in all parts of the zona externa, and in the pituitary stalk. At birth they display a biphasic evolution made up of a disappearance of the corticoliberin immunoreactivity followed by an accumulation accompanied by the appearance of a few immunoreactive perikarya in the paraventricular nucleus.

Animals↗

[Immunocytochemical study of the ontogenesis of the CRF-containing neuroglandular system in the human hypothalamus (author's transl)].

In the human fetus, the first anti CRF-stained fibres appear in the median eminence during the 16th week. From the 17th week, they are more numerous and they establish neurohemal terminals close to the superficial capillaries and around some of the developing intra-eminential vascular loops. In new born infants infundibular CRF-containing processes and terminals are strongly immunoreactive and very few CRF-containing perikarya can be detected in the paraventricular nucleus.

Corticotropin-Releasing Hormone↗

Quantitative immunocytochemical studies on the gonadotrophs isolated from the pituitary of the male rat.

Quantitative studies on the population of the gonadotropic cells in the pituitary of adult male rats were performed after trypsic dissociation of the pituitary glands and immunoenzymatic staining with anti-beta-LH or anti-beta-FSH antisera. Number, area and extinction of labelled cells were measured by use of an image analyser and a cytophotometer. The gonadotrophs represent approximately 14% of the pituitary cells. The mean area of gonadotrophs is significantly larger after staining with anti-beta-LH serum than after staining with anti-beta-FSH serum. Planimetric measurement of the gonadotrophs reveals their variability in size ranging between 30 and 160 microns2. Moreover, the size distribution depends on the staining serum used: more numerous small-sized cells (less than 75 microns2) are stained with anti-beta-FSH serum than with anti-beta-LH serum, which conversely stains more numerous large-sized cells. Cytophotometric measurements indicate that immunostaining varies greatly among cells of the same size class and that the staining intensity appears to increase according to the cell size. These results emphasize the morphofunctional heterogeneity of the gonadotropic cell population.

Animals↗

[Corticoliberin neurons in the rat brain].

A new peptidergic paraventriculo-infundibular system has been revealed using anti-corticoliberin (CRF) antibodies. The localization of its perikarya in the paraventricular nuclei as well as the distribution of its fibres and perivascular nerve-endings within the median eminence are different from those of other systems stained with antibodies directed against gonadoliberin, somatostatin, vasopressin or oxytocin.

Animals↗

[Ontogenesis of pro-opio-melano-cortin neurons in the rat].

Immunocytochemical study of the pro-opio-melano-cortin neurones in rat fetuses and newborns indicates that: 1) they appear precociously in the mediobasal hypothalamus, as early as day 13 of fetal development, that is to say 3 days before pro-opio-melano-cortin-containing pituitary cells; 2) between day 13 and day 17 they display synchronous changes in their intracellular patterns of immunoreactivity, arguing in favour of their cyclic secreting activity, which precedes the establishing of their projections; 3) beginning with day 18 until birth, the somatal immunoreactivity disappears transitorily; during the same period and the first postnatal days, their immunoreactive fibres extend in various brain regions.

Adrenocorticotropic Hormone↗

Infundibular neurons of the human hypothalamus simultaneously reactive with antisera against endorphins, ACTH, MSH and beta-LPH.

In man, discrete neurons of the infundibular (arcuate) nucleus contain compounds that can be stained with anti-endorphin (alpha and beta), anti-ACTH, anti-MSH (alpha and beta) and anti-beta-LPH immune sera (I.S.). In the fetus, certain neurons stain with anti-beta-endorphin or anti((17--39)ACTH starting from the 11th week of fetal life. At the ultrastructural level, these neurons contain elementary granules that are immunoreactive with anti-beta-endorphin. In the adult, neurons immunoreactive with anti-beta-endorphin are found in the infundibular nucleus. Their axonal fibers terminate around blood vessels in the neurovascular zone and in the pituitary stalk, or establish contacts with non-immunoreactive perikarya of the infundibular nucleus. These neurons can be stained with anti(17--39)ACTH and anti-beta-endorphin I.S. The most reactive are also stained moderately with anti-alpha-MSH, anti-beta-MSH, anti-beta-LPH, anti-alpha-endorphin, or anti(1--24)ACTH I.S. These results indicate that, in man, compound(s) identical with or immunologically related to endorphins, beta-LPH, ACTH and MSH are secreted by certain hypothalamic neurons. These agents probably originate from a common precursor molecula similar to the so-called pro-opiocortin.

Adrenocorticotropic Hormone↗

Neurons of the rat hypothalamus reactive with antisera against endorphins, ACTH, MSH and beta-LPH.

In rat brains intraventricularly injected with colchicine, the same discrete neurons of the arcuate and ventromedial nuclei can be stained with antisera against alpha- and beta-endorphins, (1-24)ACTH, (17-39)ACTH, alpha- and beta-MSH, and beta-LPH, as demonstrated by comparative studies in consecutive serial sections. These neurons are strongly reactive with anti-(17-39)ACTH, anti-beta-endorphin, anti-alpha-MSH and anti-beta-MSH, and more faintly stained with anti-alpha-endorphin, anti-beta-LPH and anti-(1-24)ACTH. Exceptionally, neurons reactive with anti-(17-39)ACTH and anti-beta-endorphin are poorly stained or completely negative with anti-alpha-MSH and anti-beta-MSH. Immunoreactive fibers end in the lateral median eminence and in the arcuate nucleus proper, or form ascending pathways along the third ventricle. Comparative studies with other antisera or with the Falck and Hillarp technique show that these neurons differ from the elements producing LH-RH, somatostatin, neurophysin, oxytocin, vasopressin and dopamine. These results suggest that the same neurons of the rat hypothalamus synthesize several neuropeptides identical with or immunologically related to endorphins, ACTH, alpha-MSH and beta-LPH, probably arising from a common precursor molecule similar to that found in the corticotropic cells of the pituitary. These neuropeptides of a common cellular and molecular origin might be involved in basic processes of the central nervous system as neurotramsmitters or neuromodulators.

Adrenocorticotropic Hormone↗

Comparative study of the neuronal populations containing beta-endorphin, corticotropin and dopamine in the arcuate nucleus of the rat hypothalamus.

Neurons simultaneously immunoreactive with anti-beta-endorphin and anti-(17-39) corticotropin (anti(17-39) ACTH) have been detected in the arcuate and ventromedial nuclei of the hypothalamus of colchicine-treated rats. These neurons are different from those fluorescent with the Falck and Hillarp technique. These results show that in the arcuate nucleus, immunoreactive ACTH and beta-endorphine are stored in the same neurons which are different from dopamine-containing neurons.

Adrenocorticotropic Hormone↗

[Immunocytologic analysis, in rat hypothalamus, of neurons producing peptides related to endorphin, ACTH, MSH and beta-LPH. Comparison with other peptidergic and monoaminergic neurons].

In rat hypothalamus intraventricularly injected with colchicine, the same neurons of the ventral region are stained with I.S. against alpha and beta-endorphin, (1-24) and (17-39) ACTH, alpha and beta-MSH, and beta-LPH. They are distinct from those producing LH-RH, somatostatin, neurophysin, and dopamine. These results suggest that the same neurons elaborate peptides identical with or immunologically related to endorphins, ACTH, alpha-MSH and beta-LPH, probably issued from a common precursor.

Adrenocorticotropic Hormone↗

[Immunocytochemical study of the maturation of the hypothalamo-neuro-hypophysial axes in the human fetus (author's transl)].

1. The development of the hypothalamo-neurohypophysial system was studied using immunocytochemistry with various antisera : anti-neurophysin, anti-oxytocin, anti-vasopressin, anti-vasotocin and anti-somatostatin. 2. Immunocytochemical investigation shows that anti-vasopressin and anti-vasotocin sera react with both vasopressin and vasotocin, whereas the anti-oxytocin serum specifically reveals the oxytocin-containing structures (Fig. 1g, h, i). 3. Perikarya stained with anti-neurophysin, anti-vasopressin and anti-vasotocin sera can be seen from the 11th week of fetal life (Fig. 1a) first in the supra-optic nucleus (SON), then in the para-ventricular nucleus (PVN). Their axons reach the neural lobe as early as the 11th week (Fig. 1b, c). 4. Oxytocin-containing perikarya appear simultaneously in the PVN (Fig. 1e) and SON during the 13th week. 5. From the 16th week, neurons stained with the anti-somatostatin serum can be seen among the neurophysin-positive cell-bodies of the SON and PVN. 6. The various populations of magnocellular neurons show a significant increase in number, especially up to the 19th week, and an increase in their hormonal content up to birth.

Animals↗