Immunoreactive Perikarya Research Articles

Response of NPY immunoreactivity in the tadpole brain exposed to energy rich and energy depleted states

The central control of feeding in animals depends upon the alternating actions of orexigenic and anorectic peptides. Studies at understanding the food intake mechanisms have emphasised the role of Neuropeptide Y as a potent orexigenic peptide in the brain. The aim of this study is to investigate the response of NPY system to positive and negative energy states and elucidate a holistic response of NPY expression throughout the brain of a tadpole model. The pre-metamorphic tadpoles of Euphlyctis cyanophlyctis were subjected to fasting, or intra-cranially injected with glucose or 2-deoxy-d-Glucose (2DG)-a metabolic antagonist of glucose and the response of the NPY system in the entire brain was studied using immunohistochemistry. Glucose injections reduced the basal expression of NPY- immunoreactive perikarya (upto 20%) in the olfactory bulb, nucleus pre-opticus, infundibulum, raphe nucleus and the distal lobe of pituitary. These regions responded to the intracranial injections of 2DG by increasing the expression of NPY up to 30%. Animals deprived of food also possessed the same response except that the increase was much intense in the 2DG injected tadpoles. Our observations lead us to the conclusion that NPY containing neurons in the discrete brain areas may be involved in the maintenance of glucose homeostasis in amphibians and, since these regions also contain the glucose sensing neurons, we further suggest that the release of NPY might be regulated by the glucose sensing neurons of the brain.

Cocaine- and amphetamine–regulated transcript peptide and calcium binding proteins immunoreactivity in the superficial layers of the superior colliculus in the guinea pig: Implications for visual sensory processing

The purpose of this study was to investigate the distribution and colocalization of cocaine- and amphetamine-regulated transcript peptide (CART) and three calcium-binding proteins (calbindin, calretinin and parvalbumin) in the superficial layers of the superior colliculus (SCs) in the guinea pig. The CART immunoreactivity was observed exclusively in the solitary fibers and neuropil, which formed various CART-ir tiers, that corresponded partially or entirely to anatomically defined layers of the SCs. The CART-ir structures exhibited a characteristic morphology with bundles of densely intermingled neuronal fibers and terminals. This pattern of CART immunoreactivity in the visually driven SCs strongly indicates that CART peptide as a putative neurotransmitter may play an important role in processing of visual information. Double-labeling immunofluorescence showed that CART did not colocalize with either calcium binding proteins (CaBPs). Immunolabeling for CaBPs revealed the presence of different neuronal populations, which were concentrated in variously pronounced tiers. Contrary to CART, the CaBPs immunoreactivity in perikarya was relatively high and CaBPs containing neurons displayed a variety of sizes and somatodendritic morphologies. Generally, CaBPs patterns in the SCs of the guinea pig differ, to some extent, from those of other rodents. These results prove the importance of studying the neurochemical cytoarchitecture of diverse mammals.

Hypobaric Preconditioning Modifies Group I mGluRs Signaling in Brain Cortex.

The study assessed involvement of Ca(2+) signaling mediated by the metabotropic glutamate receptors mGluR1/5 in brain tolerance induced by hypoxic preconditioning. Acute slices of rat piriform cortex were tested 1 day after exposure of adult rats to mild hypobaric hypoxia for 2 h at a pressure of 480 hPa once a day for three consecutive days. We detected 44.1 ± 11.6 % suppression of in vitro anoxia-induced increases of intracellular Ca(2+) levels and a fivefold increase in Ca(2+) transients evoked by selective mGluR1/5 agonist, DHPG. Western blot analysis of cortical homogenates demonstrated a 11 ± 4 % decrease in mGluR1 immunoreactivity (IR), and in the nuclei-enriched fraction a 12 ± 3 % increase in IR of phospholipase Cβ1 (PLCβ1), which is a major mediator of mGluR1/5 signaling. Immunocytochemical analysis of the cortex revealed increase in the mGluR1/5 and PLCβ1 IR in perikarya, and a decrease in IR of the neuronal inositol trisphosphate receptors (IP3Rs). We suggest that enhanced expression of mGluR5 and PLCβ1 and potentiation of Ca(2+) signaling may represent pro-survival upregulation of Ca(2+)-dependent genomic processes, while decrease in mGluR1 and IP3R IR may be attributed to a feedback mechanism preventing excessive intracellular Ca(2+) release.

Nesfatin-1/nucleobindin-2 like immunoreactivity in the olfactory system, brain and pituitary of frog, Microhyla ornata

Nesfatin-1 is a recently discovered anorectic protein derived from the precursor nucleobindin-2 (NUCB2). While nesfatin-1 has been widely studied in mammals, and goldfish, there are no reports of nesfatin-1 in amphibians. Using immunohistochemistry and Western blot analysis, this study assessed the distribution of NUCB2/nesfatin-1 in the brain of frog Microhyla ornata. NUCB2/nesfatin-1 like immunoreactivity was found in the olfactory receptor neurons, Bowman’s glands and in the olfactory epithelium of medial diverticulum. In the brain, immunoreactive perikarya were seen in the anterior preoptic area, magnocellular nucleus, suprachiasmatic nucleus, ventromedial thalamic nucleus, posterior thalamic nucleus, nucleus infundibularis ventralis and dorsalis, and the cerebellar nucleus. NUCB2/nesfatin-1like immunoreactivity was also detected in the pineal and pituitary glands of frog. The presence of NUCB2/nesfatin-1 in the key brain regions suggest possible roles for this protein in the regulation of physiological processes in frogs.

Aspartate‐containing neurons of the brainstem and rostral spinal cord of the sea lamprey Petromyzon marinus: Distribution and comparison with γ‐aminobutyric acid

ABSTRACTThe amino acid L‐aspartate (ASP) is one of the most abundant excitatory neurotransmitters in the mammalian brain, but its distribution in other vertebrates has not yet been well characterized. We investigated the distribution of ASP in the brainstem and rostral spinal cord of the adult sea lamprey by using ASP immunohistochemistry. Our results indicate that ASP is accumulated in specific neurons, but not in glia (tanycytes). ASP‐immunoreactive neuronal populations were rather similar as the glutamatergic populations reported in the adult sea lamprey (Villar‐Cerviño et al. [2013] J Comp Neurol 521:522–557), although some important differences were noted. Characteristically, the largest reticular neurons of the lamprey brainstem (Müller cells) showed ASP immunoreactivity in perikarya and processes, in contrast to the absence or faint glutamate immunoreactivity reported in these perikarya. We also compared the distribution of ASP and γ‐aminobutyric acid (GABA) in brainstem neurons by using double immunofluorescence methods. In regions such as the midbrain tectum, dorsal isthmus, and motor nuclei, ASP and GABA immunoreactivity was mostly located in different neurons, whereas in other nuclei (torus semicircularis, octavolateralis area, parvocellular reticular formation), many of the ASP‐immunonegative neurons displayed colocalization with GABA. These results, together with those of our previous studies of colocalization of glutamate and GABA, suggest that some lamprey neurons may co‐release both excitatory and inhibitory neurotransmitters. Further investigation is needed to elucidate the pathways of uptake and release of ASP by ASP‐immunoreactive neurons. Our results indicate that ASP is a neurotransmitter in the central nervous system representative of agnathans, the earliest vertebrate group. J. Comp. Neurol. 522:1209–1231, 2014. © 2013 Wiley Periodicals, Inc.

Aspartate‐containing neurons of the brainstem and rostral spinal cord of the sea lamprey Petromyzon marinus: Distribution and comparison with γ‐aminobutyric acid

The amino acid L-aspartate (ASP) is one of the most abundant excitatory neurotransmitters in the mammalian brain, but its distribution in other vertebrates has not yet been well characterized. We investigated the distribution of ASP in the brainstem and rostral spinal cord of the adult sea lamprey by using ASP immunohistochemistry. Our results indicate that ASP is accumulated in specific neurons, but not in glia (tanycytes). ASP-immunoreactive neuronal populations were rather similar as the glutamatergic populations reported in the adult sea lamprey (Villar-Cerviño et al. [2013] J Comp Neurol 521:522-557), although some important differences were noted. Characteristically, the largest reticular neurons of the lamprey brainstem (Müller cells) showed ASP immunoreactivity in perikarya and processes, in contrast to the absence or faint glutamate immunoreactivity reported in these perikarya. We also compared the distribution of ASP and γ-aminobutyric acid (GABA) in brainstem neurons by using double immunofluorescence methods. In regions such as the midbrain tectum, dorsal isthmus, and motor nuclei, ASP and GABA immunoreactivity was mostly located in different neurons, whereas in other nuclei (torus semicircularis, octavolateralis area, parvocellular reticular formation), many of the ASP-immunonegative neurons displayed colocalization with GABA. These results, together with those of our previous studies of colocalization of glutamate and GABA, suggest that some lamprey neurons may co-release both excitatory and inhibitory neurotransmitters. Further investigation is needed to elucidate the pathways of uptake and release of ASP by ASP-immunoreactive neurons. Our results indicate that ASP is a neurotransmitter in the central nervous system representative of agnathans, the earliest vertebrate group.

Mapping of Neurotensin in the Alpaca (Lama pacos) Brainstem

We studied the distribution of cell bodies and fibres containing neurotensin (NT) in the brainstem of the alpaca using an indirect immunoperoxidase technique. Immunoreactive fibres were widely distributed throughout the brainstem, whereas the distribution of cell bodies was less widespread. Immunoreactive perikarya were only found in the mesencephalic and bulbar reticular formation, periaqueductal grey, nucleus of the solitary tract, laminar spinal trigeminal nucleus and in the inferior colliculus. A high density of fibres containing NT was found in the dorsal nucleus of the raphe, marginal nucleus of the brachium conjunctivum, locus coeruleus, inferior colliculus, inter-peduncular nucleus, substantia nigra, periaqueductal grey, reticular formation of the mesencephalon, pons and medulla oblongata, nucleus of the solitary tract, laminar spinal trigeminal nucleus, hypoglossal nucleus, inferior central nucleus and in the tegmental reticular nucleus. The widespread distribution indicates that NT might be involved in multiple physiological actions in the alpaca brainstem; this must be investigated in the future as alpacas lives from 0 m above sea level to altitudes of up 5000 m and hence the involvement of this neuropeptide in special and unique regulatory physiological mechanisms could be suggested.

Distribution of methionine-enkephalin in the minipig brainstem

We have studied the distribution of immunoreactive cell bodies and axons are containing methionine-enkephalin in the minipig brainstem. Immunoreactive axons were widely distributed, whereas the distribution of perikarya was less widespread. A high or moderate density of axons containing methionine-enkephalin were found from rostral to caudal levels in the substantia nigra, nucleus interpeduncularis, nucleus reticularis tegmenti pontis, nucleus dorsalis raphae, nucleus centralis raphae, nuclei dorsalis and ventralis tegmenti of Gudden, locus ceruleus, nucleus sensorius principalis nervi trigemini, nucleus cuneatus externalis, nucleus tractus solitarius, nuclei vestibularis inferior and medialis, nucleus ambiguus, nucleus olivaris inferior and in the nucleus tractus spinalis nervi trigemini. Immunoreactive perikarya were observed in the nuclei centralis and dorsalis raphae, nucleus motorius nervi trigemini, nucleus centralis superior, nucleus nervi facialis, nuclei parabrachialis medialis and lateralis, nucleus ventralis raphae, nucleus reticularis lateralis and in the formatio reticularis. We have also described the presence of perikarya containing methionine-enkephalin in the nuclei nervi abducens, ruber, nervi oculomotorius and nervi trochlearis. These results suggest that in the minipig the pentapeptide may be involved in many physiological functions (for example, proprioceptive and nociceptive information; motor, respiratory and cardiovascular mechanisms).

Long term estradiol-17β administration changes population of the dorsal root ganglia neurons innervating the ovary in the sexually mature gilts

The influence of estradiol-17β (E₂) overdose on the number and distribution of neurons in the dorsal root ganglia (DRGs) supplying the ovary of adult pigs was investigated. The numbers of ovarian substance P (SP)-, calcitonin gene-related peptide (CGRP)-, galanin (GAL)-, pituitary adenylate cyclase-activating polypeptide (PACAP)-, neuronal isoform of nitric oxide synthase (nNOS)- and estrogen receptors (ERs)-immunoreactive perikarya were also determined. On day 3 of the estrous cycle, the ovaries of both the control and experimental gilts were injected with retrograde tracer Fast Blue. From day 4 of the estrous cycle to the expected day 20 of the second studied cycle, the experimental gilts were injected with E₂, while the control gilts received oil. The DRGs Th16-L5 were then collected and processed for double-labelling immunofluorescence. Injections of E₂ increased the E₂ level in the peripheral blood ∼4-5-fold and reduced the following in the DRGs: the total number of Fast Blue-positive perikarya, the number of large perikarya, the population of perikarya in the L2 and L3 ganglia, the numbers of SP- and/or CGRP-, PACAP-, nNOS-immunoreactive perikarya and the number of large perikarya expressing ERs subtype α and β. These results show that long-term E₂ treatment of adult gilts affects both the spatial and neurochemical organization pattern of ovary sensory innervation. Our findings suggest that elevated E₂ levels occurring during pathological states may regulate the transmission of sensory modalities from the ovary to the spinal cord.

Long-term estradiol-17β administration reduces population of neurons in the sympathetic chain ganglia supplying the ovary in adult gilts

Elevated levels of endogenous estrogens occurring in the course of pathological states of ovaries (follicular cysts, tumors) as well as xenoestrogens may result in hyperestrogenism. In rat, a close relationship between estrogens and sympathetic and sensory neurons supplying the genito-urinary system was reported. Recently, we have shown that long-term estradiol-17β (E 2) administration affected morphological and immunochemical organization of the sympathetic ovarian neurons in the caudal mesenteric ganglion of adult gilts. In this study, the influence of E 2 overdose on the number and distribution of neurons in the sympathetic chain ganglia (SChG) projecting to the ovary of adult pigs was investigated. The numbers of ovarian dopamine-β-hydroxylase (DβH-), neuropeptide Y (NPY-), somatostatin (SOM-), galanin (GAL-) and estrogen receptors (ERs-) immunoreactive perikarya as well as the density of the intraganglionic nerve fibers containing DβH and/or NPY, SOM, GAL were also determined. On day 3 of the estrous cycle the ovaries of both the control and experimental gilts were injected with retrograde neuronal tracer Fast Blue, to identify the neurons innervating gonads. From day 4 of the estrous cycle to the expected day 20 of the second studied cycle, the experimental gilts were injected with E 2, while the control gilts were receiving oil. After the last E 2/oil injection, the SChG Th16–S2 were collected and processed for double-labeling immunofluorescence. Injections of E 2: (1) increased the E 2 level in the peripheral blood ~ 4–5 fold, (2) reduced the total number of Fast Blue-positive postganglionic neurons in the ganglia under investigation, (3) decreased the number of perikarya in the L2–L4 ganglia, (4) reduced the number of perikarya in the ventral, dorsal and central regions of the SChG, (5) decreased the numbers of DβH +/NPY + and DβH +/GAL + perikarya and the numbers of DβH + but NPY −, SOM − and GAL − perikarya in the SChG, (6) decreased the number of perikarya expressing ERs subtype α and β, and (7) decreased the total number of the intraganglionic nerve fibers containing DβH and/or NPY. These results show that long-term E 2 treatment of adult gilts down-regulates the population of both noradrenergic and ERs expressing the SChG ovary supplying neurons. Our findings suggest also that elevated E 2 levels that occur during pathological states may regulate gonadal function(s) by affecting ovary supplying neurons.

Expression of PINK1 in the brain, eye and ear of mouse during embryonic development

PINK1 is a 581 amino acid protein with a serine/threonine kinase domain and an N-terminal mitochondrial targeting motif. The enzyme is expressed in the brain as well as in several tissues such as heart, skeletal muscle, liver, kidney, pancreas and testis. In the present study, we have investigated by Western blot analysis and immunohistochemistry the presence and distribution of PINK1 in the brain, eye and inner ear of mouse during embryonic development. In the brain we detected two PINK1 molecular isoforms of 55 kDa and 66 kDa. Immunoreactive perikarya first appeared at stage E15 in the diencephalon within the thalamus, the hypothalamus, the periventricular layers of the third ventricle and in the rhombencephalon at level of the pons. Subsequently, new PINK1-positive neurons were found in the midbrain within the floor and the periventricular layers of the ventral wall of the mesencephalic vesicle (stage E17) as well as in the neopallial cortex, the tegmentum of the midbrain and the periventricular region of the caudal part of the rhombencephalon (stage E19). At P0, PINK1-immunoreactive cells appeared in the striatum, the mantle layer and caudal part of the medulla oblongata and the cerebellum. The spatio-temporal expression of PINK1 and its heterogeneous distribution suggest that the enzyme might be involved in neuroregulatory processes during embryogenesis. In the eye, PINK1-immunoreactivity was found in the lens and in the cornea, whereas in the inner ear the enzyme was expressed in the ependymal and subependymal cells of the saccule and in the semicircular canals indicating that PINK1 plays a role in the development of these sensory organs.

Distribution and characterization of Corazonin in the central nervous system of Triatoma infestans (Insecta: Heteroptera)

The distribution of corazonin in the central nervous system of the heteropteran insect Triatoma infestans was studied by immunohistochemistry. The presence of corazonin isoforms was investigated using MALDI-TOF mass spectrometry in samples containing the brain, the subesophageal ganglion, the corpora cardiaca–corpus allatum complex and the anterior part of the aorta. Several groups of immunopositive perikarya were detected in the brain, the subesophageal ganglion and the thoracic ganglia. Regarding the brain, three clusters were observed in the protocerebrum. One of these clusters was formed by somata located near the entrance of the ocellar nerves whose fibers supplied the aorta and the corpora cardiaca. The remaining groups of the protocerebrum were located in the lateral soma cortex and at the boundary of the protocerebrum with the optic lobe. The optic lobe housed immunoreactive somata in the medial soma layer of the lobula and at the level of the first optic chiasma. The neuropils of the deutocerebrum and the tritocerebrum were immunostained, but no immunoreactive perikarya were detected. In the subesophageal ganglion, immunostained somata were found in the soma layers of the mandibular and labial neuromeres, whereas in the mesothoracic ganglionic mass, they were observed in the mesothoracic, metathoracic and abdominal neuromeres. Immunostained neurites were also found in the esophageal wall. The distribution pattern of corazonin like immunoreactivity in the central nervous system of this species suggests that corazonin may act as a neurohormone. Mass spectrometric analysis revealed that [Arg 7]-corazonin was the only isoform of the neuropeptide present in T. infestans tissue samples.

Long-term Estradiol-17.BETA. Administration Decreases the Number of Neurons in the Caudal Mesenteric Ganglion Innervating the Ovary in Sexually Mature Gilts

The effect of estradiol-17β (E(2)) on the number and distribution of neurons in the caudal mesenteric ganglion (CaMG) supplying the ovary of adult pigs was investigated. Also, the numbers of ovarian dopamine-β-hydroxylase (DβH-), neuropeptide Y (NPY-), somatostatin (SOM-), galanin (GAL-) and estrogen receptor (ER)-immunoreactive perikarya as well as the density of the intraganglionic nerve fibers containing DβH and/or NPY, SOM, GAL were determined. E(2) was administered i.m. from day 4 of the first studied estrous cycle to the expected day 20 of the second studied cycle. Injections of E(2) (1) increased the E(2) level in the peripheral blood approximately 4-5 fold, (2) decreased the number of small-sized Fast Blue-positive postganglionic neurons in the CaMG, (3) decreased the number of small perikarya in the ventral, dorsal and central regions of the CaMG, (4) decreased the number of large perikarya in the dorsal and central regions, (5) decreased the number of small and large perikarya in the CaMG that were DβH(+)/NPY(+), (6) decreased the number of small DβH(+) but NPY(-) perikarya, (7) decreased the number of small perikarya coded DβH(+)/SOM(+) and DβH(+)/SOM(-), (8) decreased the number of small DβH(+)/GAL(-) perikarya, (9) decreased the number of small and large perikarya expressing ER subtypes α and β and (10) decreased the total number of nerve fibers in the CaMG containing DβH and/or NPY and DβH and/or GAL. These results show that long-term E(2) treatment of adult gilts downregulates the populations of both noradrenergic and ERs expressing ovarian neurons in the CaMG. Our findings suggest also that elevated E(2) levels that occur during pathological states may regulate gonadal function(s) by affecting ovary supplying neurons.

D‐serine is distributed in neurons in the brain of the sea lamprey

The amino acid D-serine is an endogenous coagonist of N-methyl-D-aspartate (NMDA) receptors in mammals that has been shown to play an important role in synaptic function, behavior, learning, and memory. The distribution and cellular location of D-serine in the brain of the sea lamprey was investigated by using immunofluorescence methods. One major finding of our study, unlike early studies of mammals, was the localization of D-serine immunoreactivity in perikarya and dendrites of neurons, whereas D-serine immunoreactivity was not generally observed in the lamprey glia. D-serine-immunoreactive neurons were observed in different brain regions, including the olfactory bulb, medial pallium, thalamus, torus semicircularis, isthmus, and reticular formation. The colocalization of D-serine with gamma-aminobutyric acid (GABA) was also studied with a double-immunofluorescence technique. The relationship between D-serine and glycine immunoreactivities was studied in alternate parallel series of sections stained for either D-serine/GABA or glycine/GABA. Colocalization with GABA was observed in various D-serine-immunoreactive populations, and codistribution and possible colocalization with glycine was also observed in some populations, mainly in the dorsal isthmic gray, medial octavolateral nucleus, dorsal column nucleus, interpeduncular nucleus, and reticular formation. Although numerous fibers were strongly GABA- and glycine-immunoreactive, D-serine immunoreactivity was observed mostly in cell perikarya and dendrites. The present results indicate that the D-serine immunoreactive cells are small to medium-sized neurons, some exhibiting classical inhibitory neurotransmitters, in which D-serine might be acting as a modulator. The neuronal distribution of D-serine and its frequent colocalization and/or codistribution with the two main inhibitory neurotransmitters appeared early in vertebrates.

Identification of PINK1 in the brain, eye and ear of mouse during embryonic development

Event Abstract Back to Event Identification of PINK1 in the brain, eye and ear of mouse during embryonic development Marta D'Amora1*, Manuela Marcoli2, Cristiano Angelini1, Alberta Mandich1, Chiara Cervetto2 and Mauro Vallarino1 1 University of Genoa, Department of Biology, Italy 2 University of Genoa, Department of Experimental Medicine, Italy PINK1 is a 581 amino acid protein with a serine/threonine kinase domain and an N-terminal mitochondrial targeting motif. The enzyme is expressed in the brain as well as in several tissues such as heart, skeletal muscle, liver, kidney, pancreas and testis. In the present study, we have investigated by Western blot analysis and immunohistochemistry the presence and distribution of PINK1 in the brain, eye and inner ear of mouse during embryonic development. In the brain we detected a PINK1 molecular form of 66 kDa. Immunoreactive perikarya first appeared at stage E15 in the diencephalon within the thalamus, the hypothalamus, the periventricular layers of the third ventricle and in the rhombencephalon at level of the pons. Subsequently, new PINK1-positive neurons were found in the midbrain within the floor and the periventricular layers of the ventral wall of the mesencephalic vesicle (stage E17) as well as in the neopallial cortex, the tegmentum of the midbrain and the periventricular region of the caudal part of the rhombencephalon (stage E19). At P0, PINK1¬immunoreactive cells appeared in the striatum, the mantle layer and caudal part of the medulla oblongata and the cerebellum. The spatio-temporal expression of PINK1 and its heterogeneous distribution suggest that the enzyme might be involved in neuroregulatory processes during embryogenesis. In the eye, PINK1-immunoreactivity was found in lens and in the cornea, whereas in the inner ear the enzyme was expressed in the ependymal and subependymal cells of the saccule and in the semicircular canals indicating that PINK1 plays a role in the development of these sensory organs. Keywords: comparative endocrinology Conference: 25th Conference of the European Comparative Endocrinologists, Pécs, Hungary, 31 Aug - 4 Sep, 2010. Presentation Type: Conference Presentation Topic: Comparative endocrinology Citation: D'Amora M, Marcoli M, Angelini C, Mandich A, Cervetto C and Vallarino M (2010). Identification of PINK1 in the brain, eye and ear of mouse during embryonic development. Front. Endocrinol. Conference Abstract: 25th Conference of the European Comparative Endocrinologists. doi: 10.3389/conf.fendo.2010.01.00072 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Aug 2010; Published Online: 29 Aug 2010. * Correspondence: Dr. Marta D'Amora, University of Genoa, Department of Biology, Genoa, Italy, marta.damora@iit.it Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Marta D'Amora Manuela Marcoli Cristiano Angelini Alberta Mandich Chiara Cervetto Mauro Vallarino Google Marta D'Amora Manuela Marcoli Cristiano Angelini Alberta Mandich Chiara Cervetto Mauro Vallarino Google Scholar Marta D'Amora Manuela Marcoli Cristiano Angelini Alberta Mandich Chiara Cervetto Mauro Vallarino PubMed Marta D'Amora Manuela Marcoli Cristiano Angelini Alberta Mandich Chiara Cervetto Mauro Vallarino Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

FOS EXPRESSION IN TYROSINE HYDROXYLASE CONTAINING HYPOTHALAMIC NEURONS IN CRH-KO MICE: EFFECT OF IMMOBILIZATION STRESS

Little is known about the response of tyrosine hydroxylase (TH) containing hypothalamic neurons to stress in corticoliberine deficient (CRH-KO) mice. This study was aimed to extend this issue and reveal the data leading to a better understanding of physiological/anatomical plasticity of hypothalamic TH cells in response to acute immobilization stress (IMO) as well as of possible of CRH body deficiency contribution in the regulation of TH cells during stress. We examined the topographic distribution of TH protein immunolabeled perikarya in selected hypothalamic structures including the paraventricular (PVN), supraoptic (SON), periventricular (PeVN), arcuate (ArcN), dorsomedial (DMN), and ventromedial (VMN) nuclei and extrahypothalamic zona incerta (ZI) in CRH-KO and wild type (WT) mice. The animals were perfused with fixative 120 min after a single IMO stress. The brains were removed, cryo-sectioned throughout the hypothalamus and Fos-TH co-localizations were processed immunohistochemically. Fos protein was visualized by diaminobenzidine (DAB) intensified with nickel ammonium sulphate, while TH cells were labeled only with DAB chromogen. The evaluation of Fos-TH co-labeled perikarya was performed with the use of computerized Leica light microscope and expressed as the percentage of total amount of TH labeled cells. From the qualitative point of view, the present data indicate similar anatomical distribution of TH immunoreactive perikarya in all brain structures investigated in both WT and CRH-KO mice, while from the quantitative point of view only TH cells in the DMN of CRH-KO mice showed a trend for increased activation by IMO. In several hypothalamic structures the basic population of TH neurons was not affected by the absence of endogenous CRH. Based on the data of this study it can also be assumed that despite of the presence of direct reciprocal connections between PVN and DMN neurons, PVN CRH neurons possibly are not participating in the regulation of TH neurons in the DMN during IMO stress. Hypothalamic nuclei - Fos-immunohistochemistry - Tyrosine hydroxylase - Immobilization stress - CRH knockout mice.

Type-1 angiotensin receptors are expressed and transported in motor and sensory axons of rat sciatic nerves

Angiotensin II (Ang II) and its type-1 receptor (AT(1)) occur in neurons at multiple locations within the organism, but the basic biology of the receptor in the nervous system remains incompletely understood. We previously observed abundant AT(1)-like binding sites and intense expression of AT(1) immunoreactivity in perikarya of the dorsal root ganglion and ventral horn of the rat spinal cord. We have now examined the receptor in rat sciatic nerve, including the dynamics of its axonal transport. Ligand-binding autoradiography of resting nerve showed "hot spots" of (125)I-Ang II binding that could be specifically blocked by the AT(1) antagonist, losartan. Immunohistochemistry with an AT(1)-antibody validated by Western blots also showed patches of AT(1)-reactivity in nerve. These patches were localized around large myelinated axons with faint immunoreactivity in their lumens. Sixteen hours after nerve ligation there was no change in the patches or hot spots, but luminal AT(1)-reactivity increased dramatically in a narrow zone immediately above the ligature. With double ligation there was a pronounced accumulation of AT(1) immunoreactivity proximal to the upstream ligature and a very slight accumulation distal to the second ligature. This asymmetric pattern of accumulation, confirmed by quantitative receptor binding autoradiography, probably reflected axonal transport rather than local production of receptor. Retrograde tracing and stereological analysis to determine the source of transported AT(1) indicated that many AT(1)-positive fibers arise in the ventral horn, and a larger number arise in dorsal root ganglia. A corresponding result was obtained with double-label immunohistochemistry of ligated nerve, which showed AT(1) accumulations in both motor and sensory fibers. We conclude that somatic sensory and motor neurons of the rat export substantial quantities of AT(1) into axons, which transport them to the periphery. The physiologic implications of this finding require further investigation.

Tissue distribution of Ret, GFRalpha-1, GFRalpha-2 and GFRalpha-3 receptors in the human brainstem at fetal, neonatal and adult age

Occurrence and localization of receptor components of the glial cell line-derived neurotrophic factor (GDNF) family ligands, the Ret receptor tyrosine kinase and the GDNF family receptor (GFR) alpha-1 to -3, were examined by immunohistochemistry in the normal human brainstem at fetal, neonatal, and adult age. Immunoreactive elements were detectable at all examined ages with uneven distribution and consistent pattern for each receptor. As a rule, the GFRalpha-1 and GFRalpha-2 antisera produced the most abundant and diffuse tissue labelling. Immunoreactive perikarya were observed within sensory and motor nuclei of cranial nerves, dorsal column nuclei, olivary nuclear complex, reticular formation, pontine nuclei, locus caeruleus, raphe nuclei, substantia nigra, and quadrigeminal plate. Nerve fibers occurred within gracile and cuneate fasciculi, trigeminal spinal tract and nucleus, facial, trigeminal, vestibular and oculomotor nerves, solitary tract, medial longitudinal fasciculus, medial lemniscus, and inferior and superior cerebellar peduncles. Occasionally, glial cells were stained. Age changes were appreciable in the distribution pattern of each receptor. On the whole, in the grey matter, labelled perikarya were more frequently observed in pre- and perinatal than in adult specimens; on the other hand, in discrete regions, nerve fibers and terminals were abundant and showed a plexiform arrangement only in adult tissue; finally, distinct fiber systems in the white matter were immunolabelled only at pre- and perinatal ages. The results obtained suggest the involvement of Ret and GFRalpha receptors signalling in processes subserving both the organization of discrete brainstem neuronal systems during development and their functional activity and maintenance in adult life.

Serotonin-like Immunoreactivity in the Central and Peripheral Nervous Systems of the Interstitial AcochlideanAsperspinasp. (Opisthobranchia)

Species of Acochlidea are common members of the marine interstitial environment and defined in part by their minuscule size and highly divergent morphology relative to other benthic opisthobranchs. Despite these differences, acochlideans such as species of Asperspina display many plesiomorphic characteristics, including an unfused condition of their neural ganglia. To gain insight into the distribution of specific neural subsets within acochlidean ganglia, a species of Asperspina was studied by using anti-serotonin immunohistochemistry and epifluorescence and confocal laser scanning microscopy. Results reveal similarities between Asperspina and larger opisthobranchs in the general distribution of serotonergic perikarya in the central nervous system. Specifically, the arrangement of perikarya into regional clusters within the cerebral and pedal ganglia and the absence of immunoreactive perikarya in the pleural ganglia are similar to the model species of Aplysia californica, Pleurobranchaea californica, and Tritonia diomedea. Moreover, serotonergic innervation of the rhinophores in all opisthobranchs, including Asperspina sp., originates from the cerebral ganglion instead of directly from the rhinophoral ganglion. Serotonergic innervation of the body wall, including the epithelium, muscles, and pedal sole, appears to arise exclusively from pedal and accessory ganglia. These observations indicate a general conservation of serotonin-like immunoreactivity in the central and peripheral nervous systems of acochlidean and other benthic opisthobranchs.

Ontogeny of the somatostatin variant [Pro2,Met13]somatostatin-14 in the brain, pituitary, and sensory organs of the frogRana esculenta

Two forms of somatostatin are expressed in the frog brain, i.e., somatostatin-14 (SS1) and the [Pro(2), Met(13)]somatostatin-14 variant (SS2). We have previously described the ontogeny of SS1-immunoreactive cells in the brain of Rana esculenta. In the present study, we have investigated the distribution of prepro-SS2 (PSS2)-expressing neurons in the brain of the same species during development by using antibodies directed against the N-flanking region of SS2 (PSS2(54-66)). Immunoreactive perikarya first appeared in the ventral hypothalamus at stages IV-VII. Subsequently, positive neurons were seen in the nucleus of the diagonal band of Broca, the anterior preoptic area, the posterior tuberculum (stages VIII-XII), as well as the dorsal (stages XIII-XV) and medial (stages XIX-XX) periventricular preoptic nucleus. At metamorphic climax and in newly metamorphosed frogs, positive perikarya were found in the striatum and in the interpeduncular nucleus. PSS2(54-66)-immunoreactive fibers were already widely distributed during the first stages of development, indicating that SS2 may act as a neuromodulator and/or neurotransmitter during ontogeny. The presence of PSS2(54-66)-positive nerve fibers in olfactory structures suggests that, in tadpoles, SS2 may be involved in the processing of olfactory information. The occurrence of PSS2(54-66)-like immunoreactivity in taste buds, and in the olfactory and vomeronasal organs indicates that SS2 may mediate the unconditioned and reinforcing properties of natural chemicals. Finally, the intenseexpression of PSS2(54-66)-like immunoreactivity in melanotrope cells of the pituitary suggests that SS2 may diffuse toward the pars distalis to regulate the activity of adenohypophysial cells during tadpole development.