bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical stimulation releases nucleotides that activate P2Y1 receptors to trigger neural reflex chloride secretion in guinea pig distal colon
Authors: Cooke Helen J. , Xue Jianjing , Yu Jun Ge , Wunderlich Jacqueline , Wang Y.‐Z. , Guzman Jorge , Javed Najma , Christofi Fievos L. 
Published: December 2003

AbstractStroking the mucosal lining of the guinea pig colon with a brush elicits an intestinal neural reflex, and an increase in short‐circuit current (Isc) indicative of chloride secretion. We tested whether endogenous and exogenous nucleotides are physiologic regulators of mucosal reflexes that modulate chloride secretion. The basal Isc was augmented by 6‐N,N‐diethyl‐β,γ‐dibromomethylene‐D‐adenosine‐5′‐triphosphate (ARL67156) inhibition of nucleotide breakdown or adenosine A1 receptor blockade and reduced by apyrase inactivation of nucleotidases, P2 receptor antagonists, tetrodotoxin (TTX), or piroxicam. ARL67156 augmented, and apyrase inhibited, stroking‐evoked Isc responses. TTX and atropine inhibited nucleotide‐evoked Isc responses. The agonist potency profile for Isc, 2‐methylthioadenosine‐diphosphate (2MeSADP) = 2‐methioadenosine‐triphosphate ≫ 5′adenosine‐triphosphate (ATP) ≥ 5′adenosine‐diphosphate > 5′uridine‐triphosphate ≥ 5′uridine‐diphosphate, supports a P2Y1 receptor (R). The P2 receptor antagonists suramin and pyridoxalphosphate‐6‐azophenyl‐2′4′‐disulfonic acid, reduced stroking responses (36%) and their effects were additive. The selective P2Y1 R antagonist, 2′deoxy‐N6‐methyl adenosine 3′,5′‐diphosphate diammonium salt, reduced stroking (54%) and 2MeSADP (70%) responses at P2Y1 Rs. The P2X1/3 R agonist, α,βMeATP, increased Isc. A desensitizing dose of α,βMeATP reduced stroking Isc responses but did not prevent the 2MeSADP‐evoked Isc response. Reverse transcriptase polymerase chain reaction analysis revealed mRNAs for P2Y1 R, P2Y2 R, P2Y4 R, P2Y6 R, and P2Y12 R in submucosa. The expression of P2Y R immunoreactivity (ir) in cell bodies of submucous neurons followed the order of P2Y1 = P2Y2 ≫ P2Y4 R ir; P2Y1 Rs and P2Y2 R ir were abundant (21–50% of neurons). P2Y1 R ir was abundant in cholinergic secretomotor neurons and fewer than 2% of neuropeptide Y (NPY)/choline acetyltransferase secretomotor neurons, and P2Y2 R ir was expressed in virtually all NPY secretomotor neurons and approximately 30% of calbindin/intrinsic primary afferent neurons. P2Y4 R ir was present in NPY‐positive neurons. P2Y ir was rare or absent in varicose nerve fibers. The functional data support the hypothesis that mechanical stimulation with a brush releases nucleotides that act predominantly at P2Y1 Rs and to a lesser extent on P2X1/3 Rs to mediate reflex chloride secretion. A separate P2Y2 R neural circuit pathway exists that is not activated by mechanical forces. Other receptors including P2Y4, P2Y6, P2Y12, or P4 Rs cannot be excluded. J. Comp. Neurol. 469:1–15, 2004. © 2003 Wiley‐Liss, Inc.
Evidence for a glutamatergic projection from the zona incerta to the basal ganglia of rats
Authors: Heise Claire E. , Mitrofanis John 
Published: December 2003

AbstractThis study explores the organisation and neurochemical nature of the projections from the zona incerta (ZI) to the basal ganglia. Sprague‐Dawley rats were anaesthetised with ketamine (100 mg/kg) and Rompun (10 mg/kg), and injections of cholera toxin subunit B were made into each of the following nuclei: the ZI, the substantia nigra (SN), the pedunculopontine tegmental nucleus (PpT), and the entopeduncular nucleus (Ep). Brains were aldehyde fixed, sectioned, and processed using standard methods. Tracer‐labelled sections were then doubly labelled with antibodies to glutamate (Glu), nitric oxide synthase (NOS), parvalbumin (Pv), or glutamic acid decarboxylase (GAD; the latter two are markers for GABAergic cells); these neurochemicals characterise most types of ZI cells. After ZI injections, labelling was nonuniform across the different basal ganglia nuclei. The bulk of labelling, both anterograde and retrograde, was seen in the SN and PpT and, to a lesser extent, within the other nuclei of the basal ganglia (e.g., caudate‐putamen, globus pallidus, subthalamus, Ep). In the SN, labelling was found in both major parts of the nucleus, the pars compacta and pars reticulata. Within the PpT, however, the bulk of labelling was limited to only one of the two sectors of the nucleus, namely, the pars dissipata (PpTd). The pars compacta of the PpT (PpTc) remained largely free of labelled profiles. After CTb injections into three basal ganglia nuclei (SN, PpT, Ep), most labelled cells in the ZI were glutamate+ and very few were NOS+ or γ‐aminobutyric acidergic. Overall, the results indicate that the ZI is in a position to influence preferentially the activity of the SN and PpTd of the basal ganglia via an excitatory, glutamatergic input. J. Comp. Neurol. 468:482–495, 2004. © 2003 Wiley‐Liss, Inc.
Effects of anesthetics on hypoglossal nerve discharge and c‐fos expression in brainstem hypoglossal premotor neurons
Authors: Roda Fabrice , Pio Juliette , Bianchi Armand‐Louis , Gestreau Christian 
Published: December 2003

AbstractThis study examined the effects of anesthesia on the hypoglossal nerve and diaphragm activities and on c‐Fos expression in brainstem hypoglossal premotor neurons (pmXII). Experiments were performed in 71 rats by using halothane inhalation, pentobarbital sodium, or mixtures of α‐chloralose and urethane or ketamine and xylazine. First, various cardiorespiratory parameters were measured in the rats (n = 31) during both awake and anesthetized conditions. The volatile anesthetic halothane, but not the other anesthetics, was always associated with a strong phasic inspiratory activity in the hypoglossal nerve. Second, a double‐immunohistochemical study was performed in awake and anesthetized rats (n = 40) to gauge the level of activity of pmXII neurons. Brainstem pmXII neurons were identified after microiontophoresis of the retrograde tracer Fluoro‐Gold in the right hypoglossal motor nucleus. Patterns of c‐Fos expression at different brainstem levels were compared in five groups of rats (i.e., awake or anesthetized with halothane, pentobarbital, chloralose‐urethane, and ketamine‐xylazine). Sections were processed for double detection of c‐Fos protein and Fluoro‐Gold by using the standard ABC method and a two‐color peroxidase technique. Anesthesia with halothane induced the strongest c‐Fos expression in a restricted pool of pmXII located in the pons at the level of the Kölliker‐Fuse nucleus and the intertrigeminal region. The results demonstrated a major effect of halothane in inducing changes in hypoglossal activity and revealed a differential expression of c‐Fos protein in pmXII neurons among groups of anesthetized rats. We suggest that halothane mediates changes in respiratory hypoglossal nerve discharge by altering activity of premotor neurons in the Kölliker‐Fuse and intertrigeminal region. J. Comp. Neurol. 468:571–586, 2004. © 2003 Wiley‐Liss, Inc.
Circling behavior in the Ecl mouse is caused by lateral semicircular canal defects
Authors: Cryns Kim , Van Alphen Arjan M. , Van Spaendonck Michiel P. , Van De Heyning Paul H. , Timmermans Jean‐Pierre , De Zeeuw Chris I. , Van Camp Guy 
Published: December 2003

AbstractThe epistatic circler mouse (Ecl mouse) is a preexisting mutant, which displays a circling phenotype and hyperactivity. It has been shown that the circling phenotype in this mutant results from a complex inheritance pattern, but the vestibular pathology has not been analyzed. The present study deals with the morphological and functional basis responsible for the circling behavior in the Ecl mouse. Morphological examination of the inner ears revealed a bilateral malformation of the horizontal (lateral) semicircular canal and duct. No cochlear abnormalities were detected, and auditory brainstem response (ABR) measurements indicated that the auditory system is not affected. Investigation of the vestibuloocular reflex (VOR) in Ecl mice showed that their horizontal VOR on stimulation is virtually absent, which correlates with the morphological findings. J. Comp. Neurol. 468:587–595, 2004. © 2003 Wiley‐Liss, Inc.
Prefrontal cortical projections to the rat dorsal raphe nucleus: Ultrastructural features and associations with serotonin and γ‐aminobutyric acid neurons
Authors: Jankowski Michael P. , Sesack Susan R. 
Published: December 2003

AbstractStudies of human brain indicate that both the ventromedial prefrontal cortex (PFC) and the dorsal raphe nucleus (DRN) may be dysfunctional in major depressive illness, making it important to understand the functional interactions between these brain regions. Anatomical studies have shown that the PFC projects to the DRN, although the synaptic targets of this excitatory pathway have not yet been identified. Electrophysiological investigations in the rat DRN report that most serotonin neurons are inhibited by electrical stimulation of the PFC, suggesting that this pathway is more likely to synapse onto neighboring γ‐aminobutyric acid (GABA) neurons than onto serotonin cells. We tested this hypothesis by electron microscopic examination of DRN sections dually labeled for biotin dextran amine anterogradely transported from the PFC and immunogold‐silver labeling for tryptophan hydroxylase (TrH) or for GABA. In the DRN, the majority of PFC axons either synapsed onto unlabeled dendrites or failed to form detectable synapses in single sections. Other PFC axons synapsed onto either TrH‐ or GABA‐immunolabeled processes. Considerably more tissue sampling was necessary to detect PFC synapses onto TrH‐ than onto GABA‐labeled dendrites, suggesting that the latter connections are more common. In other cases, PFC terminals and TrH‐ or GABA‐immunoreactive dendrites either were closely apposed, without forming detectable synapses, or were separated by glial processes. These results provide potential anatomical substrates whereby the PFC can both directly and indirectly regulate the activity of serotonin neurons in the DRN and possibly contribute to the pathophysiology of depression. J. Comp. Neurol. 468:518–529, 2004. © 2003 Wiley‐Liss, Inc.
Cytoarchitecture and cortical connections of the posterior cingulate and adjacent somatosensory fields in the rhesus monkey
Authors: Morecraft R.J. , Cipolloni P.B. , Stilwell‐Morecraft K.S. , Gedney M.T. , Pandya D.N. 
Published: December 2003

AbstractThe cytoarchitecture and connections of the caudal cingulate and medial somatosensory areas were investigated in the rhesus monkey. There is a stepwise laminar differentiation starting from retrosplenial area 30 towards the isocortical regions of the medial parietal cortex. This includes a gradational emphasis on supragranular laminar organization and general reduction of the infragranular neurons as one proceeds from area 30 toward the medial parietal regions, including areas 3, 1, 2, 5, 31, and the supplementary sensory area (SSA). This trend includes a progressive increase in layer IV neurons. Area 23c in the lower bank and transitional somatosensory area (TSA) in the upper bank of the cingulate sulcus appear as nodal points. From area 23c and TSA the architectonic progression can be traced in three directions: one culminates in areas 3a and 3b (core line), the second in areas 1, 2, and 5 (belt line), and the third in areas 31 and SSA (root line). These architectonic gradients are reflected in the connections of these regions. Thus, cingulate areas (30, 23a, and 23b) are connected with area 23c and TSA on the one hand and have widespread connections with parieto‐temporal, frontal, and parahippocampal (limbic) regions on the other. Area 23c has connections with areas 30, 23a and b, and TSA as well as with medial somatosensory areas 3, 1, 2, 5, and SSA. Area 23c also has connections with parietotemporal, frontal, and limbic areas similar to areas 30, 23a, and 23b. Area TSA, like area 23c, has connections with areas 3, 1, 2, 5, and SSA. However, it has only limited connections with the parietotemporal and frontal regions and none with the parahippocampal gyrus. Medial area 3 is mainly connected to medial and dorsal sensory areas 3, 1, 2, 5, and SSA and to areas 4 and 6 as well as to supplementary (M2 or area 6m), rostral cingulate (M3 or areas 24c and d), and caudal cingulate (M4 or areas 23c and d) motor cortices. Thus, in parallel with the architectonic gradient of laminar differentiation, there is also a progressive shift in the pattern of corticocortical connections. Cingulate areas have widespread connections with limbic, parietotemporal, and frontal association areas, whereas parietal area 3 has more restricted connections with adjacent somatosensory and motor cortices. TSA is primarily related to the somatosensory‐motor areas and has limited connections with the parietotemporal and frontal association cortices. J. Comp. Neurol. 469:37–69, 2004. © 2003 Wiley‐Liss, Inc.
Expression of transcripts encoding AMPA receptor subunits and associated postsynaptic proteins in the macaque brain
Authors: Beneyto Monica , Meador‐Woodruff James H. 
Published: December 2003

AbstractGlutamate is the primary excitatory neurotransmitter in the central nervous system, regulating numerous cellular signaling pathways and controlling the excitability of central synapses both pre‐ and postsynaptically. Localization, cell surface expression, and activity‐dependent regulation of glutamate receptors in both neurons and glia are performed and maintained by a complex network of protein–protein interactions associated with targeting, anchoring, and spatially organizing synaptic proteins at the cell membrane. Using in situ hybridization, we examined the expression of transcripts encoding the AMPA receptor subunits (GluR1–GluR4) and a family of AMPA‐related intracellular proteins. We focused on PDZ‐proteins that are involved in the regulated pool and anchoring AMPA subunits to the cell membrane (PICK1, syntenin), and those maintaining the constitutive pool of AMPA receptors at the glutamatergic synapse (NSF, stargazin). In addition, we studied a fifth protein, KIAA1719, with high homology to the rat PDZ protein ABP, associated with the clustering of AMPA receptors at the glutamate synapse. The AMPA subunits showed significant differences in regional expression, especially in the neocortex, thalamus, striatum, and cerebellum. The expression of other proteins, even those related to a specific AMPA subunit (such as ABP and PICK1 to GluR2 and GluR3), often had different distributions, whereas others (like NSF) are ubiquitously distributed in the brain. These results suggest that AMPA subunits and related intracellular proteins are differentially distributed in the macaque brain, and in numerous structures there are significant mismatches, suggesting additional functional properties of the associated intracellular proteins. J. Comp. Neurol. 468:530–554, 2004. © 2003 Wiley‐Liss, Inc.
Dynamic expression patterns of Robo (Robo1 and Robo2) in the developing murine central nervous system
Authors: Sundaresan Vasi , Mambetisaeva Elvira , Andrews William , Annan Adelaide , Knöll Bernd , Tear Guy , Bannister Lawrence 
Published: December 2003

AbstractThe Robo family of molecules is important for axon guidance across the midline during central nervous system (CNS) development in invertebrates and vertebrates. Here we describe the patterns of Robo protein expression in the developing mouse CNS from embryonic day (E) 9.5 to postnatal day (P) 4, as determined by immunohistochemical labeling with an antibody (S3) raised against a common epitope present in the Robo ectodomain of Robos 1 and 2. In the spinal cord, midline‐crossing axons are initially (at E11) S3‐positive. At later times, midline Robo expression disappears, but is strongly upregulated in longitudinally running postcrossing axons. It is also strongly expressed in noncrossing longitudinal axons. Differential expression of Robo along axons was also found in axons cultured from E14 spinal cord. These findings resemble those from the Drosophila ventral nerve cord and indicate that in vertebrates a low level of Robo expression occurs in the initial crossing of the midline, while a high level of expression in the postcrossing fibers prevents recrossing. Likewise, Robo‐positive ipsilateral axons are prevented from crossing at all. However, in the brain different rules appear to apply. Most commissural axons including those of the corpus callosum are strongly S3‐positive along their whole length from their time of formation to postnatal life, but some have more complex age‐dependent expression patterns. S3 labeling of the optic pathway is also complex, being initially strong in the retinal ganglion cells, optic tract, and chiasma but thereafter being lost except in a proportion of postchiasmal axons. The corticospinal tract is strongly positive throughout its course at all stages examined, including its decussation, formed at about P2 in the central part of the medulla oblongata. J. Comp. Neurol. 468:467–481, 2004. © 2003 Wiley‐Liss, Inc.
Expression of axonin‐1 in developing amacrine cells in the chick retina
Authors: Drenhaus U. , Morino P. , Rager G. 
Published: December 2003

AbstractThis study focused on the temporal and spatial pattern of expression of the cell adhesion molecule axonin‐1 in amacrine cells and the identification of these cells in the developing chick retina. We analyzed 5–20‐day‐old chick embryos. The antigen was localized and visualized by the indirect immunogold and the immunofluorescence technique. Colocalization studies with antibodies against tyrosine hydroxylase, acetylcholinesterase, choline acetyltransferase, parvalbumin, calbindin, and calretinin served to characterize these cells further and to explore whether they have other properties in common. Axonin‐1 was expressed in amacrine cells from E8 onward in the inner nuclear, in the inner plexiform, and in the ganglion cell layer. Their maturation showed a gradient similar to that found for amacrinogenesis. Expression was closely correlated with the period when the cells develop and shape their processes. The interneurons were classified with reference to Cajal, and most of the morphological types described by him were found. In addition, some cells were considered as axon‐bearing amacrine cells. However, the total number of labeled cells was rather small. At least two morphologically different types terminated in each of the inner plexiform sublayers. Narrow‐ and wide‐field arbors indicated the existence of a diversified network. The colocalization studies revealed that the neurotransmitters and neuropeptides overlapped partially with axonin‐1 expression. This indicated that axonin‐1‐immunoreactive amacrine cells were also functionally diverse. J. Comp. Neurol. 468:496–508, 2004. © 2003 Wiley‐Liss, Inc.
Testosterone manipulation protects motoneurons from dendritic atrophy after contralateral motoneuron depletion
Authors: Fargo Keith Nolan , Sengelaub Dale Robert 
Published: December 2003

AbstractDendritic morphology is reactive to many kinds of injuries, including axotomy and deafferentation. In this study, we examined the response of motoneurons in the spinal nucleus of the bulbocavernosus (SNB), an androgen‐dependent population of motoneurons in the lumbar spinal cord of the rat, to partial motoneuron depletion. We depleted SNB motoneurons on one side only of the spinal cord by unilateral intramuscular injection of a retrogradely transported form of saporin, and examined the morphology of contralateral SNB motoneurons. Motoneuron morphology was assessed in normal control males, gonadally intact saporin‐treated males, and saporin‐treated males who had been castrated 6 weeks previously and given testosterone replacement beginning at the time of saporin injection. Untreated castrated males served as an additional control group. Four weeks after saporin treatment, SNB motoneurons contralateral to the saporin injection were retrogradely labeled with horseradish peroxidase conjugated to the cholera toxin B subunit and reconstructed in three dimensions. In gonadally intact males, unilateral motoneuron depletion caused regressive changes in contralateral SNB motoneurons: Soma size and dendritic length were both decreased. However, testosterone manipulation (i.e., castration followed by testosterone replacement) completely prevented the dendritic retraction. These data suggest a therapeutic role for testosterone in preventing, or accelerating recovery from, dendritic atrophy induced by motoneuron injury. J. Comp. Neurol. 469:96–106, 2004. © 2003 Wiley‐Liss, Inc.
Copper/zinc superoxide dismutase‐like immunoreactivity in the metamorphosing brain of the sphinx moth Manduca sexta
Authors: Schachtner Joachim , Huetteroth Wolf , Nighorn Alan , Honegger Hans‐Willi 
Published: December 2003

AbstractCu/Zn superoxide dismutase (SOD) is part of the defense mechanism that protects cells from being damaged by reactive oxygen species. During metamorphosis of the nervous system, neurons undergo various fates, which are all coupled to high metabolic activities, such as proliferation, differentiation, pathfinding, and synaptogenesis. We describe the pattern of SOD immunoreactivity of identified neurons and neuron groups in the brain of Manduca sexta from the late larva through metamorphosis into adult. We focused on neurons of the developing antennal lobes, the optic lobes, and the central brain. Our results indicate the transient expression of SOD during phases in which the neurons develop their final adult identities. Our data also suggest that the SOD immunoreactivity may be used as an indicator for the period in which developing neurons form their synapses. We also observed SOD immunoreactivity within nitric oxide‐sensitive cells as characterized by immunolabeling against 3′5′‐cyclic guanosine monophosphate and soluble guanylyl cyclase, a novel finding in insects. J. Comp. Neurol. 469:141–152, 2004. © 2003 Wiley‐Liss, Inc.
Preservation of hippocampal neuron numbers and hippocampal subfield volumes in behaviorally characterized aged tree shrews
Authors: Keuker Jeanine I.H. , de Biurrun Gabriel , Luiten Paul G.M. , Fuchs Eberhard 
Published: December 2003

AbstractAging is associated with a decreased ability to store and retrieve information. The hippocampal formation plays a critical role in such memory processes, and its integrity is affected during normal aging. We used tree shrews (Tupaia belangeri) as an animal model of aging, because in many characteristics, tree shrews are closer to primates than they are to rodents. Young and aged male tree shrews performed a holeboard spatial memory task, which permits assessment of reference and working memory. Upon completion of the behavioral measurements, we carried out modified stereological analyses of neuronal numbers in various subdivisions of the hippocampus and used the Cavalieri method to calculate the volumes of these subfields. Results showed that the working memory of aged tree shrews was significantly impaired compared with that of young animals, whereas the hippocampus‐dependent reference memory remained unchanged by aging. Estimation of the number of neurons revealed preserved neuron numbers in the subiculum, in the subregions CA1, CA2, CA3, and in the hilus of the dentate gyrus. Volume measurements showed no aging‐related changes in the volume of any of these hippocampal subregions, or in the molecular and granule cell layers of the dentate gyrus of tree shrews. We conclude that the observed changes in memory performance in aging tree shrews are not accompanied by observable reductions of hippocampal neuron numbers or hippocampal volume, rather, the changes in memory performance are more likely the result of modified subcellular mechanisms that are affected by the aging process. J. Comp. Neurol. 468:509–517, 2004. © 2003 Wiley‐Liss, Inc.