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V Pieribone

Publications and source records attributed to V Pieribone.

9 recordsLinked to original sources
PubMed2000

Multiple messengers in descending serotonin neurons: localization and functional implications.

In the present review article we summarize mainly histochemical work dealing with descending bulbospinal serotonin neurons which also express a number of neuropeptides, in particular substance P and thyrotropin releasing hormone. Such neurons have been observed both in rat, cat and monkey, and may preferentially innervate the ventral horns of the spinal cord, whereas the serotonin projections to the dorsal horn seem to lack these coexisting peptides. More recent studies indicate that a small population of medullary raphe serotonin neurons, especially at rostral levels, also synthesize the inhibitory neurotransmitter gamma-amino butyric acid (GABA). Many serotonin neurons contain the glutamate synthesizing enzyme glutaminase and can be labelled with antibodies raised against glutamate, suggesting that one and the same neuron may release several signalling substances, causing a wide spectrum of post- (and pre-) synaptic actions.

Animals↗
PubMed1998

Regulation of iron metabolism in the sanguivore lamprey Lampetra fluviatilis--molecular cloning of two ferritin subunits and two iron-regulatory proteins (IRP) reveals evolutionary conservation of the iron-regulatory element (IRE)/IRP regulatory system.

Two ferritin cDNAs were cloned from the liver and spinal cord of the sanguivore lamprey Lampetra fluviatilis, an extant representative of the ancient agnathan (jawless) stage in vertebrate evolution. The deduced proteins of 20.2 kDa (H-subunit) and 20.1 kDa (M-subunit) display 73% sequence identity, and both contain the ferroxidase center characteristic of animal H-ferritin. A highly conserved iron-responsive element (IRE) was identified in the 5' untranslated region of lamprey H-ferritin. Lamprey ferritin IRE forms a specific complex with crude lamprey and rat liver extracts, and with recombinant human iron-regulatory protein (IRP-1) in an electrophoretic mobility shift assay. Furthermore, lamprey ferritin IRE competes with labeled human ferritin IRE for binding to IRP in lamprey and mammalian extracts. Two liver cDNA sequences encoding 323 residues and 101 residues of two genetically distinct lamprey IRP were amplified by PCR. Lamprey IRP-1 and IRP-2, which are 72% identical, display about 74% sequence identity to their presumed homologues in mammals. Northern blot analysis shows that two IRP transcripts of 3.6 kb and 5.8 kb are expressed in lamprey liver. Given the ancient lineage of lampreys, the results indicate that the IRE/IRP regulatory system has remained highly conserved during the evolution of vertebrates.

Amino Acid Sequence↗
PubMed1993

Distributions of mRNAs for alpha-2 adrenergic receptor subtypes in rat brain: an in situ hybridization study.

Selective 35S-labeled oligonucleotide probes were designed to sequences of the rat alpha-2A (RG20), alpha-2B (RNG), and alpha-2C (RG10) adrenoreceptor mRNAs for use in in situ hybridization experiments on sections of unfixed rat brain, spinal cord and kidney. After hybridized sections were exposed to film or dipped in autoradiographic emulsion, specific and selective labeling patterns characteristic for each probe and region of the central nervous system were observed. Alpha-2A mRNA labeling was most pronounced in neurons in layer six of the cerebral cortex, hypothalamic paraventricular nucleus, reticular thalamic nucleus, pontine nuclei, locus coeruleus, vestibular nuclei, trapezoid nuclei, deep cerebellar nuclei, nucleus tractus solitarii, ventrolateral medullary reticular formation, and the intermediolateral cell column of the thoracic spinal cord. In some of these locations, the receptor mRNA, in all probability, is present in noradrenaline and perhaps adrenaline neurons. The alpha-2B probe, which primarily labels the kidney, gave only a very light signal in the thalamus in the central nervous system after extended exposure times. Alpha-2C mRNA labeling was primarily observed in the olfactory bulb, cerebral cortex, islands of Calleja, striatum, hippocampal formation, cerebellar cortex, and dorsal root ganglia. Labeling patterns disappeared when excess unlabeled probes were added to their respective radiolabeled probes, or when sense probes were employed. When a hybrid antisense probe homologous to all three alpha-2 probes was used, labeling patterns also disappeared. The present study therefore justifies the pharmacological subclassification of alpha-2 receptors by providing anatomical evidence for specific and selective cell groups in the rat central nervous system containing mRNA for three alpha-2 receptor subtypes.

Amino Acid Sequence↗
PubMed1992

Galanin message-associated peptide (GMAP)- and galanin-like immunoreactivities: overlapping and differential distributions in the rat.

Using the indirect immunofluorescence method the distribution of galanin message associated peptide (GMAP)- and galanin-like immunoreactivities (LI) was compared in brain, intestine and some endocrine tissues of rat. In general, neurons in the peripheral and central nervous system contained both immunoreactivities. However, in retina the cones were GMAP-positive but galanin-negative. A strong GMAP-LI was observed in the prolactin cells in the anterior lobe of the pituitary and in the insulin cells in the islets of Langerhans in the pancreas, whereas incubation with galanin antiserum resulted in staining of fewer cells (anterior pituitary) or a very weak fluorescence (pancreas). The results show that most neurons express both GMAP- and galanin-LI, but raise the possibility that in some systems there is a tissue specific, posttranslational differential processing of preprogalanin.

Amino Acid Sequence↗
PubMed1991

Afferent regulation of locus coeruleus neurons: anatomy, physiology and pharmacology.

Tract-tracing and electrophysiology studies have revealed that major inputs to the nucleus locus coeruleus (LC) are found in two structures, the nucleus paragigantocellularis (PGi) and the perifascicular area of the nucleus prepositus hypoglossi (PrH), both located in the rostral medulla. Minor afferents to LC were found in the dorsal cap of the paraventricular hypothalamus and spinal lamina X. Recent studies have also revealed limited inputs from two areas nearby the LC, the caudal midbrain periaqueductal gray (PAG) and the ventromedial pericoerulear region. The pericoeruleus may provide a local circuit interface to LC neurons. Recent electron microscopic analyses have revealed that LC dendrites extend preferentially into the rostromedial and caudal juxtaependymal pericoerulear regions. These extracoerulear LC dendrites may receive afferents in addition to those projecting to LC proper. However, single-pulse stimulation of inputs to such dendritic regions reveals little or no effect on LC neurons. Double-labeling studies have revealed that a variety of neurotransmitters impinging on LC neurons originate in its two major afferents, PGi and PrH. The LC is innervated by PGi neurons that stain for markers of adrenalin, enkephalin or corticotropin-releasing factor. Within PrH, large proportions of LC-projecting neurons stained for GABA or met-enkephalin. Finally, in contrast to previous conclusions, the dorsal raphe does not provide the robust 5-HT innervation found in the LC. We conclude that 5-HT inputs may derive from local 5-HT neurons in the pericoerulear area. Neuropharmacology experiments revealed that the PGi provides a potent excitatory amino acid (EAA) input to the LC, acting primarily at non-NMDA receptors in the LC. Other studies indicated that this pathway mediates certain sensory responses of LC neurons. NMDA-mediated sensory responses were also revealed during local infusion of magnesium-free solutions. Finally, adrenergic inhibition of LC from PGi could also be detected in nearly every LC neuron tested when the EAA-mediated excitation is first eliminated. In contrast to PGi, the PrH potently and consistently inhibited LC neurons via a GABAergic projection acting at GABAA receptors within LC. Such PrH stimulation also potently attenuated LC sensory responses. Finally, afferents to PGi areas that also contain LC-projecting neurons were identified. Major inputs were primarily autonomic in nature, and included the caudal medullary reticular formation, the parabrachial and Kölliker-Fuse nuclei, the PAG, NTS and certain hypothalamic areas.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗