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Seale AP, Yamaguchi Y, Johnstone WM, Borski RJ, Lerner DT, Grau EG. Endocrine regulation of prolactin cell function and modulation of osmoreception in the Mozambique tilapia. Gen Comp Endocrinol 2013; 192:191-203. [PMID: 23722201 DOI: 10.1016/j.ygcen.2013.05.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 05/11/2013] [Accepted: 05/14/2013] [Indexed: 01/06/2023]
Abstract
Prolactin (PRL) cells of the Mozambique tilapia, Oreochromis mossambicus, are osmoreceptors by virtue of their intrinsic osmosensitivity coupled with their ability to directly regulate hydromineral homeostasis through the actions of PRL. Layered upon this fundamental osmotic reflex is an array of endocrine control of PRL synthesis and secretion. Consistent with its role in fresh water (FW) osmoregulation, PRL release in tilapia increases as extracellular osmolality decreases. The hyposmotically-induced release of PRL can be enhanced or attenuated by a variety of hormones. Prolactin release has been shown to be stimulated by gonadotropin-releasing hormone (GnRH), 17-β-estradiol (E2), testosterone (T), thyrotropin-releasing hormone (TRH), atrial natriuretic peptide (ANP), brain-natriuretic peptide (BNP), C-type natriuretic peptide (CNP), ventricular natriuretic peptide (VNP), PRL-releasing peptide (PrRP), angiotensin II (ANG II), leptin, insulin-like growth factors (IGFs), ghrelin, and inhibited by somatostatin (SS), urotensin-II (U-II), dopamine, cortisol, ouabain and vasoactive intestinal peptide (VIP). This review is aimed at providing an overview of the hypothalamic and extra-hypothalamic hormones that regulate PRL release in euryhaline Mozambique tilapia, particularly in the context on how they may modulate osmoreception, and mediate the multifunctional actions of PRL. Also considered are the signal transduction pathways through which these secretagogues regulate PRL cell function.
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Affiliation(s)
- A P Seale
- Hawai'i Institute of Marine Biology, University of Hawaii, Kaneohe, HI 96744, USA.
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Cioni C, De Vito L, Greco A, Pepe A. The caudal neurosecretory system and its afferent synapses in the goldfish, Carassius auratus: morphology, immunohistochemistry, and fine structure. J Morphol 1998; 235:59-76. [PMID: 9397580 DOI: 10.1002/(sici)1097-4687(199801)235:1<59::aid-jmor5>3.0.co;2-j] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Morphological features of the goldfish caudal neurosecretory system were investigated by means of immunohistochemical localization of urotensins I and II (UI and UII) and electron microscopic examination of the caudal neurosecretory neurons, the urophysis, and the synaptic neuropil. The aim of the work is to provide a detailed morphological description of the afferent synapses to the caudal neurons and to analyze their distribution through the rostrocaudal extension of the caudal neurosecretory system. Three morphologically different types of neurosecretory cells have been identified according to size and shape: large, medium, and small Dahlgren cells. The three different-sized cells share similar patterns of immunoreactivity with the UI (or oCRF) and the UII antisera. Electron microscopic examination of the synaptic neuropil throughout the caudal system revealed the presence of four types of terminals: dense-cored-vesicle end bulbs (DC), spherical-vesicle end bulbs (S), flattened-vesicle end bulbs (F), and granular-vesicle end bulbs (G). The present study demonstrates that the small Dahlgren cells receive different synaptic inputs from the large and the medium neurosecretory cells. Indeed, G terminals are only found on the small Dahlgren cells, whereas DC, S, and F terminals are distributed on the large, medium, and small Dahlgren cell bodies and proximal processes.
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Affiliation(s)
- C Cioni
- Department of Animal and Human Biology, La Sapienza University, Rome, Italy.
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McKeon TW, Cohen SL, Black EE, Kriebel RM, Parsons RL. Monoamines in the caudal neurosecretory complex: biochemistry and immunohistochemistry. Brain Res Bull 1988; 21:37-42. [PMID: 3219599 DOI: 10.1016/0361-9230(88)90117-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Monoaminergic inputs to the caudal neurosecretory complex (CNc) of Poecilia latipinna have been identified using histofluorescence and immunohistochemical techniques. The present study was undertaken to identify specific monoamines and determine the relative contribution of indolamines and catecholamines in supraspinal and intrinsic innervation of the nucleus. The CNc was deafferented by transecting the spinal cord rostral to the CNc. Ten days subsequently, CNc of spinal-transected and control fish were processed for either biochemical or immunohistochemical analysis. Norepinephrine and serotonin were detected in pooled samples of control CNc. Following deafferentation, the content of both monoamines was diminished. Using immunohistochemical labeling for serotonin or for the catecholamine-synthesizing enzymes, tyrosine hydroxylase (TH) or dopamine-beta-hydroxylase (DBH), the number of monoamine fibers was decreased in deafferented CNc compared to control. A substantial serotonergic innervation remains after deafferentation, as evidenced by serotonin-positive neurons and heavy, varicose fibers. Occasional TH/DBH-positive cells and fibers remain after deafferentation. These data suggest that both norepinephrine and serotonin are associated with descending supraspinal projections, while serotonin predominates as the intrinsic monoamine.
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Affiliation(s)
- T W McKeon
- Department of Anatomy and Neurobiology, University of Vermont, Burlington 05405
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Miller KE, Kriebel RM. Cytology of brain stem neurons projecting to the caudal neurosecretory complex: an HRP-electron microscopic study. Brain Res Bull 1986; 16:183-8. [PMID: 3697787 DOI: 10.1016/0361-9230(86)90032-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Brain stem projections to the neurons in the caudal neurosecretory complex (CNC) of Poecilia sphenops (molly) have been studied with HRP retrograde tracing. Using light microscopic procedures, HRP-labelled neurons were located in the reticular nucleus of the medulla (RMN) and in the vicinity of the nucleus of the medial longitudinal fascicle (NMLF). The present study was undertaken to examine the cytology of the brain stem neurons that project to the caudal neurosecretory complex using combined HRP-electron microscopic methods. Cells in the midbrain NMLF containing HRP-filled profiles were located bilaterally close to the midline and just beneath the ependyma. HRP reaction product was found additionally in the neurosecretory cells of the midbrain dorsal tegmental magnocellular nucleus (DTMN) located dorsal to the NMLF. Cells containing HRP-labelled profiles were also seen in the RMN and in neurons dorsal-lateral to the RMN. This latter group of neurons contained small dense core vesicles in addition to HRP labelled dense bodies.
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Fryer JN, Boudreault-Chateauvert C, Kirby RP. Pituitary afferents originating in the paraventricular organ (PVO) of the goldfish hypothalamus. J Comp Neurol 1985; 242:475-84. [PMID: 4086672 DOI: 10.1002/cne.902420403] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The diencephalon of nonmammalian vertebrates contains aminergic perikarya situated beneath the ependyma lining the third ventricle, known as the paraventricular organ (PVO). Catecholamines were visualized in the goldfish forebrain by formaldehyde-glutaraldehyde-induced fluorescence. Neuronal somata containing catecholamines were found in three paraventricular nuclei--the nucleus recessus posterioris (NRP), the nucleus recessus lateralis (NRL), and the nucleus posterioris paraventricularis (NPPv)--which may be considered to constitute the PVO of the goldfish. Lesion-degeneration investigations were conducted to determine whether the PVO contributes to the innervation of the goldfish pituitary. Following electrothermic lesions of the NRP, degenerating axons and nerve terminals were observed in the rostral pars distalis and in the proximal pars distalis, but not in the neuro-intermediate lobe of the pituitary. Following lesions of the NRL or of the NPPv, degenerating axons and nerve terminals were observed in the rostral pars distalis, the proximal pars distalis, and in the neurointermediate lobe. These observations demonstrate that the PVO is a source of pituitary afferents in the goldfish and suggest that the PVO is a source of the catecholaminergic innervation of the teleost pituitary.
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Grau EG, Nishioka RS, Young G, Bern HA. Somatostatin-like immunoreactivity in the pituitary and brain of three teleost fish species: somatostatin as a potential regulator of prolactin cell function. Gen Comp Endocrinol 1985; 59:350-7. [PMID: 2864306 DOI: 10.1016/0016-6480(85)90391-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Somatostatin-like immunofluorescence occurs in the hypothalamus and neurohypophysis of three euryhaline teleosts: tilapia, killifish, and mudsucker. This immunofluorescence was eliminated by incubating the primary antibody with excess somatostatin or somatostatin-28 but not with urotensin II, a partial analogue of somatostatin. In all three fishes, the strongest reaction was seen in the proximal pars distalis and parts of the pars intermedia. Strongly fluorescing processes from cells of the preoptic nucleus extend toward the pituitary. Distinct fluorescence was also associated with the neurohypophysis penetrating into the rostral pars distalis in the tilapia but not in the killifish or mudsucker. In the tilapia, an extensive network of immunofluorescent fibers and small cells were present in the anterior dorsolateral telencephalon, in addition to a moderately fluorescing group of cells anterolateral to the preoptic nucleus. A small area of diffuse fluorescence was also seen in the anterior dorsolateral midbrain tegmentum. Previous physiological studies have implicated somatostatin as a regulator of prolactin cell activity in tilapia. The present study demonstrates the route by which somatostatin may be delivered to the rostral pars distalis to inhibit prolactin secretion.
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James VA, Wigham T. Evidence for dopaminergic and serotonergic regulation of prolactin cell activity in the trout Salmo gairdneri. Gen Comp Endocrinol 1984; 56:231-9. [PMID: 6150877 DOI: 10.1016/0016-6480(84)90035-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The control of prolactin (PRL) cell activity in Salmo gairdneri was investigated in vivo and in vitro. In some in vivo experiments treatment was followed by estimation of pituitary PRL content by gel electrophoresis or of PRL cell nuclear area by light microscopy. In the remainder, treatment was followed by incubation of the pituitary glands in drug-free medium for estimation of PRL synthesis and release. The dopamine precursor, L-dopa (20 mg/kg), reduced pituitary PRL content. Conversely, the dopamine-receptor blocker, domperidone (10 mg/kg), increased total PRL content and amount released in the subsequent incubation. The initial serotonin precursor, L-tryptophan (75 mg/kg), increased pituitary PRL content and PRL cell nuclear area. 5-HTP (20 mg/kg), the immediate serotonin precursor, increased both percentage PRL release and total PRL levels during subsequent incubation. Pargyline (25 mg/kg) treatment to inhibit serotonin catabolism elevated PRL levels in pituitary and medium during subsequent incubation. The serotonin synthesis blocker, parachlorophenylalanine (pCPA; 100 mg/kg), nonsignificantly reduced PRL cell nuclear area. When this was followed by incubation, percentage PRL release and total PRL fell significantly. During in vitro incubation, dopamine (2 micrograms/ml) reduced the release of PRL into the medium, while serotonin (10(-5) M) increased PRL release. These results suggest that both an inhibitory dopaminergic and a stimulatory serotonergic system may be involved in PRL cell regulation in S. gairdneri. The lack of any significant effect of cortisol (1 microgram/ml), somatostatin (300 ng/ml). GABA (100 mg/ml) and TRH 100 ng/ml) on PRL release in vitro suggested little or no involvement of these putative regulatory factors in PRL cell regulation.
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4 The Cellular Origin of Pituitary Gonadotropins in Teleosts. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/s1546-5098(08)60288-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Ekström P, Veen T. The Monoaminergic Paraventricular Organ in the TeleostIctalurus nebulosusLeSueur, with Special Reference to Its Vascularization. ACTA ZOOL-STOCKHOLM 1982. [DOI: 10.1111/j.1463-6395.1982.tb00758.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Audet C, Chevalier G. Monoaminergic innervation of the caudal neurosecretory system of the brook trout Salvelinus fontinalis in relation to osmotic stimulation. Gen Comp Endocrinol 1981; 45:189-203. [PMID: 6116645 DOI: 10.1016/0016-6480(81)90104-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Abstract
The caudal neurosecretory system of the molly, Poecilia sphenops (Poeciliidae) was studied by light and electron microscopy. In this species the cell bodies form a focal nuclear group in the caudal spinal cord. The neurosecretory cells are in contact with glial elements, axon terminals, and the lumen of the central canal. The axons of the neurosecretory cells form a definitive tract, which leaves the spinal cord proper to penetrate a well defined neurohemal organ, the urophysis. The urophysis contains an abundance of neurosecretory granules within the neurosecretory axonal processes. This study is the first ultrastructural study of the caudal neurosecretory system in this family of fishes, which has been used as a neuroendocrine model. This species acclimates easily to the laboratory aquarium and may be most suitable for further studies on the effects of changes in external salinity on the caudal neurosecretory system.
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Kobayashi Y, Kobayashi H, Ohshiro S, Osumi Y, Fujiwara M. Monoaminergic innervation of the caudal neurosecretory system of the carp, Cyprinus carpio. Anat Histol Embryol 1980; 9:65-72. [PMID: 6445698 DOI: 10.1111/j.1439-0264.1980.tb00841.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Leonhardt VH. Ependym und Circumventriculäre Organe. HANDBUCH DER MIKROSKOPISCHEN ANATOMIE DES MENSCHEN 1980. [DOI: 10.1007/978-3-642-81358-0_3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Batten TF, Ingleton PM, Ball JN. Ultrastructural and formaldehyde-fluorescence studies on the hypothalamus of Poecilia latipinna (Teleostei, Cyprinodontiformes). Gen Comp Endocrinol 1979; 39:87-109. [PMID: 573720 DOI: 10.1016/0016-6480(79)90195-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Fryer JN, Woo NY, Gunther RL, Bern HA. Effect of urophysial homogenates on plasma ion levels in Gillichthys mirabilis (Teleostei:Gobiidae). Gen Comp Endocrinol 1978; 35:238-44. [PMID: 689358 DOI: 10.1016/0016-6480(78)90068-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Olivereau M. Effect of pimozide on the cytology of the eel pituitary. I. Prolactin-secreting cells. Cell Tissue Res 1978; 189:219-30. [PMID: 657239 DOI: 10.1007/bf00209271] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Pimozide, a specific blocker of dopaminergic receptors, was injected for 4 to 9 days in freshwater (FW) eels or eels acclimated to sea water (SW), for 10 to 30 days. The daily dose was 100 or 200 microgram/100 g. In FW, pimozide induces a nuclear hypertrophy in the prolactin (PRL) cells of eels; these elongated cells increase in height. The amount of erythrosinophilic granules in the cytoplasm, initially reduced, increases. Plasma electrolyte values are not modified: only the plasma sodium level slightly rises with the higher dose. In SW, PRL cells appear less active. After 10 days, this hypoactivity is not yet fully evident; pimozide stimulates PRL cells without affecting electrolyte values. After 1 month in SW, PRL cells are stimulated with pimozide and a slight regranulation may occasionally occur. The response in SW is never as marked as it is in FW; a high dose is not more effective than a low one. The higher dose significantly raises Na+, Ca2+ and Cl- plasma levels. These data suggest that prolactin synthesis and release increase with pimozide. They corroborate the hypothesis of a hypothalamic inhibitory control on PRL secretion mediated through dopaminergic fibers in the eel, but other factors may also be involved in this regulation in addition to the effect of salinity.
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Wigham T, Nishioka RS, Bern HA. Factors affecting in vitro activity of prolactin cells in the euryhaline teleost Sarotherodon mossambicus (Tilapia mossambica). Gen Comp Endocrinol 1977; 32:120-31. [PMID: 408224 DOI: 10.1016/0016-6480(77)90142-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Wigham T, Ball JN. In vivo evidence for catecholaminergic inhibition of prolactin secretion in the teleostPoecilia latipinna. ACTA ACUST UNITED AC 1976. [DOI: 10.1007/bf00689303] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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