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J Cardot

Publications and source records attributed to J Cardot.

At least 19 recordsLinked to original sources
PubMed1999

Melanin-concentrating hormone-producing neurons in birds.

The peptidergic melanin-concentrating hormone (MCH) system was investigated by immunocytochemistry in several birds. MCH perikarya were found in the periventricular hypothalamic nucleus near the paraventricular organ and in the lateral hypothalamic areas. Immunoreactive fibers were very abundant in the ventral pallidum, in the nucleus of the stria terminalis, and in the septum/diagonal band complex, where immunoreactive pericellular nets were prominent. Many fibers innervated the whole preoptic area, the lateral hypothalamic area, and the infundibular region. Some fibers also reached the dorsal thalamus and the epithalamus. The median eminence contained only sparse projections, and the posterior pituitary was not labeled. Thus, in birds, a neurohormonal role for MCH is not likely. Immunoreactive fibers were observed in other regions, such as the intercollicular nucleus, stratum griseum periventriculare (mesencephalic tectum), central gray, nigral complex (especially the ventral tegmental area), reticular areas, and raphe nuclei. Although no physiological investigation concerning the role of MCH has been performed in birds, the distribution patterns of the immunoreactive perikarya and fibers observed suggest that MCH may be involved in functions similar to those described in rats. In particular, the projections to parts of the limbic system (ventropallidal ganglia, septal complex, hypothalamus, dorsal thalamus, and epithalamus) and to structures concerned with visceral and other sensory information integration suggest that MCH acts as a neuromodulator involved in a wide variety of physiological and behavioral adaptations (arousal) with regard to feeding, drinking, and reproduction.

Animals↗
PubMed1994

Melanin-concentrating hormone-producing neurons in reptiles.

Melanin-concentrating hormone (MCH)-like producing neurons were mapped in the brains of several reptiles using antisera (AS) prepared against salmon MCH (sMCH) and peptides derived from the rat MCH precursor (rMCH, NGE, NEI) or cross-reacting with these peptides (anti-GRF37 and anti-alpha-MSH). MCH neurons were detected in the periventricular and lateral hypothalamic nuclei. The coexpression of MCH-, GRF37- and NEI-like immunoreactivities suggests that the reptile precursor presents large sequence homologies with the rat/human precursor. MCH neurons project to many brain areas, but fibers are very scarce in the median eminence, and the neurohypophysis is devoid of immunoreactive processes. Thus the MCH produced by these neurons would not be a neurohormone as in fish. The great quantity of processes observed in the optic lobes and in the olfactive encephalic areas (particularly in the septum) is most probably related to behavioral and adaptive regulations controlled by the hypothalamus.

Animals↗
PubMed1990

[Apparent immunoreactivity of CRF in the tentacles of the mollusk Helix pomatia].

In the Gastropod Mollusc Helix pomatia (Pulmonata: Stylommatophora), an antiserum raised against ovine CRF 41 reveals a neuropeptide in some primary sensory neurons distributed beneath the epithelium of the higher tentacles (optic) and the lower tentacles. The collar cells and the lateral cells of both kinds of tentacles are innervated by some CRF immunoreactive fibers. Considering the given results, these processes probably originate in the central ganglia, but also in the tentacular sensory neurons. The neuropeptide revealed by our immunserum would be involved in the regulation of the exocrine secretion of the collar and lateral cells. It may also take part in the regulation of the endocrine secretion of collar cells in both sorts of tentacles.

Animals↗
PubMed1988

[Peripheral distribution of a neuropeptide recognized by an antiserum raised against the mammalian CRF41, in the mollusc Helix pomatia].

Immunocytochemical methods using an antiserum raised against ovine corticoliberin revealed perikarya and processes in the central and peripheral nervous system of the Pulmonate Gastropod Helix pomatia. The coexistence of immunoreactive nerve fibres and primary sensory neurons in the intestinal wall and in the tentacles appeared particularly significant. The distribution of this peptide suggests that it could act as a sensory neurotransmitter at the central and peripheral levels.

Animals↗
PubMed1984

Corticoliberin neurons: cytophysiology, phylogeny and ontogeny.

In the rat hypothalamus, antibodies to ovine CRF41 stain neurons of a paraventriculo-infundibular neuroglandular pathway. CRF like immunoreactivity (CLI)-containing perikarya are mostly packed in the parvocellular division of the paraventricular nucleus. Their morphology and topography differ from that of other peptidergic neurons. However a few CLI perikarya are also stained with vasopressin antibodies. CLI neurons project massively to the external layer of the median eminence (ELME). Adrenalectomy induced a total depletion of ELME CLI 12 to 24 h after surgery, followed by a secondary accumulation already conspicuous 5 days later. This biphasic evolution, identical to that of ELME vasopressin, is totally prevented by a replacement therapy with dexamethasone. Reserpine also induces an acute depletion of ELME CLI and vasopressin, that can be prevented by a monoamine oxidase inhibitor pretreatment. These results indicate the involvement of CLI neurons in the corticotropic axis, suggesting that they are indeed corticoliberin neurons. Among the extrahypothalamic locations of CLI neurons their abundance in the amygdala central nucleus is of interest since it is involved in the corticotropic axis. A similar pattern of CLI was noticed in several mammalian brains and also in lower vertebrates (birds, reptiles, amphibians, fishes). Species adaptations of CLI neurons were observed: CLI neurons are of the cerebrospinal fluid contacting type in the turtle. CLI fibres terminate close to corticotrophs in the fish pituitary. This suggests a direct excitosecretory role of CRF on these cells and concurs with a CRF function of CLI peptide even in fishes. CLI processes and terminals appear in the human fetal ELME at the 16th week of development and increase in number during the following weeks. Perikarya are seen at 19 weeks. In the rat CLI fibers and perikarya were detected as early as the 18th day of fetal development. Thus, paraventriculo-infundibular CLI system develops later than corticotrophs. This chronology perfectly concurs with the results of previous physiological and experimental studies.

Adrenalectomy↗
PubMed1984

The CRF neuron: immunocytochemical study.

In the central nervous systems of several species belonging to different vertebrate classes, immunocytochemical stainings with an antiserum to ovine CRF 41 show multiple location of CRF perikarya and various areas containing CRF fibres and terminals. These stainings reflect species and interspecies functional adaptations of the CRF neurones which constitute a prominent hypothalamo-infundibular system involved in pituitary gland control, and also interneurone systems as attested to by extrahypothalamic perikarya and by CRF perisomatal endings in several brain areas. Perikarya of the hypothalamo-infundibular system are mainly packed in the paraventricular nucleus (mammals, birds) or in homologous areas, e.g.: paraventricular organ (turtle) where they are CSF-contacting neurones and preoptic nucleus (amphibians, fishes). In all species but fish, CRF fibres end in the median eminence (ME) against portal vessels. In fish, CRF processes terminate in the peripheral areas of proadenohypophyseal neurodigitations, close to corticotrophs. In all species these stainings are abolished by preabsorption of the serum by CRF. In fishes, reptiles and amphibians they are also suppressed by urotensin I, which is thought to be the teleost's CRF. Adrenalectomy experiments in the rat provided evidence for a corticosteroid regulation of ME CRF: short term (12-24 hr) adrenalectomy induces a complete depletion of CRF immunoreactivity followed by a secondary accumulation (5-20 days). This biphasic evolution is prevented by a dexamethasone replacement therapy. Inhibitory role of catecholamines on CRF release was indicated by: disappearance of ME CRF, induced by a single reserpine injection and suppression of this effect by monoamineoxidase inhibitor (pargyline or tranylcypromine) pretreatment. CRF fibres were first observed in the ME at the 16th week of fetal development in the human, and at the 18th day in the rat fetus. Thus, immunoreactive CRF system develops later than pituitary corticotrophs.

Adrenalectomy↗
PubMed1983

Immunofluorescent evidence of an FMRFamide-like peptide in the peripheral nervous system of the gastropod mollusc Helix aspersa.

An antiserum raised against the FMRFamide peptide revealed a highly developed peripheral nervous system in the mollusc Helix aspersa. Immunoreactive fibres associated with muscular fibres are observed in all organs. Cell bodies are frequently seen, for example in the digestive and genital tracts. The antiserum also revealed associations between immunoreactive fibres and non-reactive perikarya. In Helix aspersa an FMRFamide-like peptide is most likely a neurotransmitter/neuromodulator for muscular and peripheral nervous activity.

Animals↗
PubMed1983

Reserpine-induced depletion of corticoliberin (CRF)-like immunoreactivity in the zona externa of the rat median eminence.

An acute reserpine treatment has the same selective and marked depleting effect on corticoliberin-like immunoreactivity as on vasopressin-like immunoreactivity in the rat zona externa of the median eminence. Somatostatin and gonadoliberin immunoreactivities appear unmodified. Reserpine effect is blocked by pretreatment with monoamine oxidase inhibitors (pargyline or tranylcypromine). Present results support the notion of an inhibitory role of monoamines, particularly catecholamines, on the release of corticoliberin.

Animals↗
PubMed1983

[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↗
PubMed1982

[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↗
PubMed1982

[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↗
PubMed1982

[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↗
PubMed1979

[The monoamines in molluscs. II. Dopamine and neurotransmission. Cardiac dopaminergic innervation in Helix pomatia (author's transl)].

In the molluscs, dopamine is very probably a chemical transmitter at the level of both the central nervous system and certain peripheral structures. The heart of Helix pomatia does not have any intrinsic innervation, but it receives extrinsic innervation from fibres coming from the visceral nerve. Formaldehyde fluorescence histochemistry localizes the cardiac catecholamines in some of these fibres and in their endings. However, dopamine, which dominates, does not seem to be a transmitter involved in cardioregulation in the same way as 5-hydroxytryptamine. The quantities of active dopamine (stimulants) cannot be compared with those required for a neurotransmitter. This is also true for noradrenaline. Dopamine more certainly plays a role at the metabolic and tropic level by acting within a more or less short period as a regulator of cellular activity and contractility. The Helix heart is a suitable model for future research in this field.

Animals↗