bluuebunny/crossref_metadata_2025_split huggingface dataset:
Locustatachykinin immunoreactivity in the blowfly central nervous system and intestine
Authors: Lundquist C. Tomas , Clottens Frank L. , Holman G. Mark , Riehm John P. , Bonkale Willy , Nässel Dick R. 
Published: January 2005

AbstractAn antiserum raised against locustatachykinin I, one of four myotropic peptides that have been isolated from the locust brain and corpora cardiaca, was characterized by enzyme‐linked immunosorbent assay (ELISA) and used for immunocytochemical detection of neurons and endocrine cells in the nervous system and intestine of the blowfly Calliphora vomitoria. The ELISA characterization indicated that the antiserum recognizes the common C‐terminus sequence of the locustatachykinins I‐III. Hence, the cross reaction with locustatachykinin IV is less, and in competitive ELISAs no cross reaction was detected with a series of vertebrate tachykinins tested. It was also shown that the antiserum recognized material in extracts of blowfly heads, as measured in ELISA. In high‐performance liquid chromatography the extracted locustatachykinin‐like immunoreactive (Lom TK‐LI) material eluted in two different ranges. A fairly large number of LomTK‐LI neurons was detected in the blowfly brain and thoracicoabdominal ganglion. A total of about 160 LomTK‐LI neurons was seen in the proto‐, deuto‐, and tritocerebrum and subesophageal ganglion. Immunoreactive processes from these neurons could be traced in many neuropil regions of the brain: superior and dorsomedian protocerebrum, optic tubercle, fan‐shaped body and ventral bodies of the central complex, all the glomeruli of the antennal lobes, and tritocerebral and subesophageal neuropil. No immunoreactivity was seen in the mushroom bodies or the optic lobes. In the fused thoracicoabdominal ganglion, 46 LomTK‐LI neurons could be resolved. The less evolved larval nervous system was also investigated to obtain additional information on the morphology and projections of immunoreactive neurons. In neither the larval nor the adult nervous systems could we identify any efferent or afferent immunoreactive axons or neurosecretory cells. The widespread distribution of LomTK‐LI material in interneurons suggests an important role of the native peptide(s) as a neurotransmitter or neuromodulator within the central nervous system. Additionally a regulatory function in the intestine is indicated by the presence of immunoreactivity in endocrine cells of the midgut.
Tactile sensory input regulates basal and apomorphine‐induced immediate‐early gene expression in rat barrel cortex
Authors: Steiner Heinz , Gerfen Charles R. 
Published: January 2005

AbstractClipping of mystacial vibrissae on one side of the rat's snout result in sensorimotor asymmetries in normal behavior and in behavior induced by the dopamine receptor agonist, apomorphine. Immediate‐carly gene expression, a marker for short‐term changes in neuron function, was used to examine wheter this sensory deprivation leads to functional changes in the somatosensory barrel cortex under experimental conditions which reveal behavioral asymmetries. The expression of c‐fos and zif 268 immediate‐early genes was assessed with in situ hybridization histochemistry. Four hours after unilateral clipping of the mystacial vibrissae, the level of zif 268 mRNA was reduced in the corresponding part of the contralateral barrel field. Injection of apoorphine (5 mg/kg) resulted in increased expression of both c‐fos and zif 268 immediate‐early genes in cortex and striatum. This apomorphine‐induced increase was blocked in the sensory‐deprived somatosensory corted. Laminar analysis of gene regulation shwoed that vibrissae removal affected immediate‐early expression in all layers of the barrel cortex. These results demonstrate that: (1) basal zif 268 gene expression in neurons of the somatosensory cortex is dependent on sensory input, (2) cortical immediate‐early gene expression is increased after dopamine receptor activation, and (3) in the barrel cortex, this increase is also dependent on sensory input. We suggest that the observed reduction in gene expression after vibrissae removal reflects decreased activation of neurons in the barrel column by removal of sensory input. © 1994 Wiley‐Liss, Inc.
Pattern of striate cortical projections to the pretectal complex in the guinea pig
Authors: Lui F. , Giolli R. A. , Blanks R. H. , Tom E. M. 
Published: January 2005

AbstractThe primary goal of this study was a determine whether the striate cortex (Oc 1) of the guinea pig projects to the pretactal nucleus of the optic tract (NOT), the first postretinal station of the horizontal optokinetic pathway, and, if so, to analyze the anatomical organization of this cortico‐NOT projection. Other goals of this investigation are to identify other pretectal nuclear projections from the visual cortex in the guinea pig, and to determine whether there is any visuotopic organization in this pathway.Axonal tracers (biocytin or 3H‐leucine) were injected into the striate cortex (Oc 1), and the tissue processed with histochemical or light autoradiographic techniques. All subcortical terminal labeling is ipsilateral in the basal ganglia and thalamic nuclei. Furthermore, projections are traced to the ipsilateral brainstem, including two areas of the pretectal complex: (1) one in the NOT, extending in some cases to the adjacent lateral portion of the posterior pretectal nucleus (PPN), and (2) one in the pars compacta of the anterior pretectal nucleus (APNc). The terminal fields in the APN are consistently located rostrally in the dorsolateral portion of the nucleus, independently of the injection site in Oc 1, whereas in the NOT the terminal fields shift slightly after injections placed in different locations in the striate cortex. A correlation of the injection sites in Oc 1 and terminal fields in the NOT reveals a loose topographic organization in the cortico‐NOT projection; accordingly, the rostrocaudal axis of the striate cortex projects to the lateromedial axis of the NOT, with a 90° rotation, whereas lateral parts of the striate cortex project diffusely throghout the rostrocaudal extent of the NOT.These data show for the first that the NOT in the guinea pig receives a substantial projection form the visual cortex. Given the fact that in the guinea pig the optokinetic nystagmus shares some of the characteristics found in cat and monkey (i.e., consistent intial fast rise in the slow phase velocity and reduced asymmetry in monocular stimulation), the present findings lend support to the hypothesis that a cortical input to the NOT is a necessary condition for these oculomotor properties to be present. © 1994 Wiley‐Liss, Inc.
Neuronal nitric oxide synthase is localized in extrinsic nerves regulating perireceptor processes in the chemosensory nasal mucosae of rats and humans
Authors: Kulkarni Anjali P. , Getchell Thomas V. , Getchell Marilyn L. 
Published: January 2005

AbstractNitric oxide synthase is the enzyme responsible for the production of the free radical gas nitric oxide, which has been implicated as an intercellular messenger in both the central and peripheral nervous systems. Immunoreactivity for nitric oxide synthase is often coincident with the histochemical demonstration of NADPH‐diaphorase activity. Using an antibody to the neuronal form of nitric oxide synthase and a histochemical technique for NADPH‐diaphorase, we have compared the localization of immunoreactivity and histochemical reaction product in the nasal mucosae of rats and humans. Immunoreactivity for neuronal nitric oxide synthase was localized in the extrinsic perivascular innervation of the olfactory and vomeronasal mucosae of rats and in the olfactory mucosa of humans. In the rat nasal mucosa, specific groups of glands were also innervated; the density of nitrinergic innervation varied among them, with vomeronasal glands and posterior glands of the nasal septum being the most densely innervated. In contrast, NADPH‐diaphorase activity was present in olfactory, vomeronasal, and septal organ receptor neurons in rats and in olfactory receptor neurons in humans as well as in numerous nerve fibers, glands, and surface epithelial cells. The localization of neuronal nitric oxide synthase in extrinsic perivascular and periglandular nerve fibers suggests that nitric oxide may modulate the perireceptor processes of local blood flow and mucus secretion that influence the access to and clearance of chemical stimuli from rat and human chemosensory mucosae. © Wiley‐Liss, Inc.
Afferent and efferent connections of the habenula in the larval sea lamprey (Petromyzon marinus L.): An experimental study
Authors: Yañez Julián , Anadon Ramón 
Published: January 2005

AbstractThe habenula is an integrative center between the striatum and the limbic and motor systems. With the aim of achieving further understanding of the evolution of this structure in vertebrates, we carried out an experimental study of the afferent and efferent connections of the habenula of larval sea lamprey. Experimental procedures included in vivo and in vitro transport after injections of horseradish peroxidase (HRP) into the habenula, telencephalon, pineal organ, dorsal thalamus, and posterior tubercle as well as carbocyanine dye tracing (DiI). The combined results of these experiments showed that the pattern of habenular connections is very simple. Most afferents appear to originate from the lobus subhippocampalis and neighboring area, whereas the only efferents found coursed in the fasciculus retroflexus to the neuropil of the nucleus interpeduncularis. This neuropil comprises a commissural region in the rostral mesencephalon, two long bilateral areas extending in the basal mesencephalon and medulla oblongata to the trigeminal level, and, finally, a caudal commissural zone. The conspicuous habenular commissure contains interhemispheric fibers that appear to form occasional contacts within the habenulae. The lamprey habenula also receives a few immunocytochemically identified fibers (somatostatinergic, catecholaminergic, and serotoninergic fibers) from other sources. © 1994 Wiley‐Liss, Inc.
Differential glycosylation of auditory and vestibular hair bundle proteins revealed by peanut agglutinin
Authors: Goodyear Richard , Richardson Guy 
Published: January 2005

AbstractUp to four morphologically distinct types of cross‐link are found between the stereocilia in the hair bundles of avian hair cells. These links are involved in mechanotransduction, force transmission across the bundle, and maintenance of hair bundle structure. They appear to be specialisations of the cell coat, but very little is known about their molecular composition. Chick inner ear tissues were therefore screened with a number of different lectins to find markers for specialisations of the hair bundle surface. One lectin, peanut agglutinin (PNA), which recognises the dissacharide Galβ1‐3GalNAc, was found to be a fairly selective marker for vestibular hair bundles, but it does not stain the stereocilia of auditory hair cells. The staining patterns observed with PNA in the vestibular system closely resemble those seen with a monoclonal antibody (mab) directed against a 275 kD component of the hair cell's apical surface known as the hair‐cell antigen (HCA). However, unlike PNA, the mab recognises both vestibular and auditory hair cells. A detailed comparison of the fluorescence staining patterns observed with PNA and the anti‐HCA mab indicates that binding sites for both ligands spatially codistribute on the surface of vestibular hair cells. The lectin and the anti‐HCA mab binding sites are both sensitive to trypsin treatment, and, with sections of the vestibular system, PNA pretreatment blocks subsequent anti‐HCA mab staining. Immunoelectron microscopy of vestibular hair bundles shows that PNA and the anti‐HCA mab both label a type of cross‐link known as the shaft connector. This link type is present on both auditory and vestibular hair bundles but reacts with PNA only in the vestibular system. The lectin jacalin, which has greater specificity for Galβ1‐3GalNAc than does PNA, also only labels vestibular and not auditory hair bundles. Although terminal sialic acid residues can block both PNA and jacalin binding, neuraminidase treatment does not unmask cryptic binding sites for these lectins on auditory hair cells but does reveal PNA and jacalin staining at a number of other locations in the inner ear. The results obtained with the lectins PNA and jacalin indicate that either the HCA or other components of the shaft links are differentially glycosylated in the vestibular and auditory epithelia of the bird. The functional significance for such a difference in glycosylation remains to be determined, but auditory and vestibular hair cells operate over different frequency ranges, and variations in glycosylation might confer different micromechanical properties on the hair bundles in these two systems. © 1994 Wiley‐Liss, Inc.
Postnatal development of voltage sensitive Na+ channels in rat brain
Authors: Xia Ying , Haddad Gabriel G. 
Published: January 2005

AbstractPrevious studies have shown that mammalian neuronal excitability increases with age, and this excitability may be related to development of Na+ channels. In addition, evidence suggests that Na+ channels are involved in the neuronal response to O2 deprivation. Because of this, we wished to examine the pharmacologic properties and neuroanatomical distribution of the Na+ channels in newborn brain and as a function of age. In this study, we used ligand‐binding techniques and autoradiography with 3H‐saxitoxin (STX) to investigate Na+‐channel distribution in brains of rats at postnatal days 0, 3, 10, 21, 35, and 120. We found that (1) in each area examined, the Scatchard plots for STX binding were linear in both immature and mature brains in a ligand concentration range of 0.4–64 nM; the slopes, however, were different between areas or ages, with Kd values ranging between 1 and 5 nM; (2) STX‐binding density was more than tenfold lower in the rostral brain and cerebellum at birth than in the adult and increased with age; (3) binding density in the newborn brainstem was higher than in other areas such as the cortex and cerebellum, which is opposite to the distribution in the adult; and (d) the brainstem had a different developing pattern with an early‐peak density level (P10–21) and a lower adult level. We conclude that (1) there is a major type of STX‐binding site in specific brain areas in the developing brain; (2) binding affinity is higher, but density lower, at birth than in the adult, especially in the rostral brain; and (3) developmental profiles of Na+ channels vary among brain areas with an early developmental time table in the brainstem and a later one in the cerebellum and rostral brain. © 1994 Wiley‐Liss, Inc.
Electrophysiological and morphological properties of light and dark cells isolated from mudpuppy taste buds
Authors: McPheeters Martha , Barber Andrew J. , Kinnamon Sue C. , Kinnamon John C. 
Published: January 2005

AbstractIsolated Necturus taste receptor cells were studied by giga‐seal whole‐cell recording and electron microscopy to correlate electrophysiological properties with taste cell structural features. Dark (type I) cells were identified by the presence of dense granular packets in the supranuclear and apical regions of the cytoplasm. In response to a series of depolarizing voltage commands from a holding potential of −80 mV, these cells exhibited a transient, TTX‐sensitive inward Na+ current, a sustained outward K+ current, and a slowly inactivating inward Ca++ current. Light (type II) cells were identified by a lack of granular packets and by an abundance of smooth endoplasmic reticulum distributed throughout the cell. In addition, isolated light cells had clear vesicular inclusions in the cytoplasm and blebs on the plasma membrane. Light cells were divided into two functional populations based upon electrophysiological criteria: cells with inward and outward currents, and cells with outward currents only. Light cells with inward and outward currents had voltage‐activated Na+, K+, and Ca++ currents with properties similar to those of dark cells. In contrast, the second group of light cells had only voltageactivated outward K+ currents in response to depolarizing voltage commands. These data suggest that dark cells and light cells with inward and outward currents are capable of generating action potentials and releasing neurotransmitters onto gustatory afferent neurons in response to taste stimulation. In contrast, light cells with outward currents only likely serve a different function in the taste bud. © 1994 Wiley‐Liss, Inc.
Loss of dopamine D2 receptors varies along the rostrocaudal axis of the hippocampal complex in alzheimer's disease
Authors: Ryoo Han L. , Joyce Jeffrey N. 
Published: January 2005

AbstractThe anatomy of the hippocampus, including the organization of its intrinsic neural circuits and afferents, is organized along a rostrocaudal axis. Dopamine D2 receptors are expressed in specific regions of the hippocampal complex (hippocampal subfields, entorhinal cortex, perirhinal cortex) and show differential expression along this axis. The dentate gyrus and CA3/CA4 subfields show higher numbers of D2 receptors in the rostral than in the caudal levels. In contrast, the subiculum shows the reverse gradient. We report here that Alzheimer's disease (AD) is associated with reduced expression of the dopamine D2 receptor, but the effects differ with respect to the rostrocaudal axis and area within the hippocampal complex. The number of D2 receptors is significantly reduced in the molecular layer of the dentate gyrus, CA3 subfield, and subiculum. For the dentate gyrus and subiculum, there were greater losses at more rostral levels. The CA3/CA4 subfields showed the greatest losses caudally. The entorhinal cortex, which shows only modest expression of D2 receptors in controls, does not exhibit reduced numbers in AD. The external laminae of the rostral perirhinal cortex showed more significant losses than more caudally in this cortical field. The regions showing loss of D2 receptors do not typically contain neuritic plaques, neurofibrillary tangles, or significant neuron loss. Thus other mechanisms must account for the unique gradient of D2 receptor loss in the hippocampus. The regions of reduced expression of dopamine D2 receptors do correlate well with the terminal zone of the dentate association pathway, the afferents from the anlygdala and perirhinal cortex, and the sources of those afferents within the amygdala and perirhinal cortex. The specific patterns of reduced D2 receptor expression in AD are likely to contribute significantly to the disrupted information flow into and out of the hippocampus and, thus, of functions subserved by this system. © 1994 Wiley‐Liss, Inc.
Spatially and temporally differentiated patterns ofc‐fosexpression in brainstem catecholamilriergic cell groups induced by cardiovascular challenges in the rat
Authors: Chan R. K. W. , Sawchenko P. E. 
Published: January 2005

AbstractBrainstem catecholaminergic neurons have been implicated as mediating adaptive autonomic and neuroendocrine responses to cardiovascular challenges. To clarify the nature of this involvement, immuno‐ and hybridization histochemical methods were used to followc‐fosexpression in these neurons in response to acute stimuli that differentially affect blood pressure and volume. From low basal levels, hypotensive hemorrhage (15%) provoked a progressive increase in the number and distribution of Fos‐immunoreactive (ir) nuclei in the nucleus of the solitary tract (NTS), the Al and C1 cell groups of the ventrolateral medulla, and in the pontine A5, locus coeruleus, and lateral parabrachial cell groups peaking at 2.0–2.5 hours after the challenge. Fos‐ir ventrolateral medullary neurons, subsets of which were identified as projecting to the paraventricular hypothalamic nucleus or spinal cord, were predominantly aminergic, whereas most of those in the NTS were not. Infusion of an angiotensin II antagonist blunted hemorrhage‐induced Fos expression in the area postrema, and attenuated that seen elsewhere in the medulla and pons. Nitroprusside‐induced isovolemic hypotension yielded a pattern of c‐fos induction similar to that seen following hemorrhage, except in the area postrema and the Al cell group, where the response was muted or lacking. Phenylephrineinduced hypertension stimulated a restricted pattern ofc‐fosexpression, largely limited to non‐aminergic neurons, whose distribution in the NTS conformed to the termination patterns of primary baroreceptor afferents, and in the ventrolateral medulla overlapped in part with those of vagal cardiomotor and depressor neurons. These findings underscore the importance of brainstem catecholaminergic neurons in effecting integrated homeostatic responses to cardiovascular challenges and their ability to responding strategically to specific modalities of cardiovascular information. They also foster testable predictions as to effector neuron populations that might be recruited to respond to perturbations in individual circulatory parameters. © 1994 Wiley‐Liss, Inc.
Microglia in the avian retina: Immunocytochemical demonstration in the adult quail
Authors: Navascués Julio , Moujahid Amale , Quesada Antonio , Cuadros Miguel A. 
Published: January 2005

AbstractImmunocytochemical techniques were used in conjunction with the QH1 antibody to study the morphological characteristics and distribution of microglia in the avascular retina of an avian species (the quail). The majority of microglial cells appeared in the outer and inner plexiform layers throughout the entire retina, whereas a few microglial cells in the nerve fiber layer were seen only in the central zone of the retina, near the optic nerve head. In the outer plexiform layer, microglial cells were star‐shaped, with processes that ramified profusely in the horizontal plane. Fine process tips extended outward radially, insinuating themselves among the photoreceptors. A regular mosaic‐like arrangement of microglial cells was evident in the outer plexiform layer, with no overlapping between adjacent cell territories. Microglial cells in the inner plexiform layer ramified through the entire width of this layer, showing radial and horizontal processes. Microglia in the inner plexiform layer also tended to be regularly distributed in a mosaic‐like fashion, although there was slight overlapping between adjacent cell territories. Microglia density in this layer was approximately twice that in the outer plexiform layer. This pattern of microglial distribution was similar to that described in vascular retinae of several species of mammals a finding that suggests that blood vessels are not responsible for the final locations of microglia in the adult retina, and that microglial precursors must migrate through long distances before they reach their precise destination. © 1994 Wiley‐Liss, Inc.