bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐dimensional properties of GnRH neuroterminals in the median eminence of young and old rats
Authors: Yin Weiling , Mendenhall John M. , Monita Monique , Gore Andrea C. 
Published: July 2009

AbstractThe decapeptide gonadotropin‐releasing hormone (GnRH), which regulates reproduction in all vertebrates, is stored in, and secreted from, large dense‐core secretory vesicles in nerve terminals in the median eminence. GnRH is released from these terminals with biological rhythms that are critical for the maintenance of normal reproduction. During reproductive aging in female rats, there is a loss of GnRH pulses and a diminution of the GnRH surge. However, information about the specific role of GnRH nerve terminals is lacking, particularly in the context of aging. We sought to gain novel ultrastructural information about GnRH neuroterminals by performing three‐dimensional (3D) reconstructions of GnRH neuroterminals and their surrounding microenvironment in the median eminence of young (4–5 months) and old (22–24 months) ovariectomized Sprague–Dawley female rats. Median eminence tissues were freeze‐plunge embedded and serial ultrathin sections were collected on slot grids for immunogold labeling of GnRH immunoreactivity. Sequential images were used to create 3D models of GnRH terminals. These reconstructions provided novel perspectives into the morphological properties of GnRH terminals and their neural and glial environment. We also noted that the cytoarchitectural features of the median eminence became disorganized with aging. Quantitative measures showed a significant decrease in the apposition between GnRH terminal membranes and glial cells. Our data suggest reproductive aging in rats is characterized by structural organizational changes to the GnRH terminal microenvironment in the median eminence. J. Comp. Neurol. 517:284–295, 2009. © 2009 Wiley‐Liss, Inc.
Developmental expression of prion protein and its ligands stress‐inducible protein 1 and vitronectin
Authors: Hajj Glaucia N.M. , Santos Tiago G. , Cook Zanith S.P. , Martins Vilma R. 
Published: July 2009

AbstractPrion protein (PrPC) is the normal isoform of PrPSc, a protein involved in neurodegenerative disorders. PrPC participates in neuritogenesis, neuroprotection, and memory consolidation through its interaction with the secreted protein stress‐inducible protein 1 (STI1) and the extracellular matrix protein vitronectin (Vn). Although PrPC mRNA expression has been documented during embryogenesis, its protein expression patterns have not been evaluated. Furthermore, little is known about either Vn or STI protein expression. In this study, PrPC, STI1, and Vn protein expression was explored throughout mouse embryonic life. We found that the distributions of the three proteins were spatiotemporally related. STI1 and Vn expression became evident at E8, earlier than PrPC, in the nervous system and heart. At E10, we observed, in the spinal cord, a gradient of expression of the three proteins, more abundant in the notochord and floor plate, suggesting that they can have a role in axonal growth. As development proceeded, the three proteins were detected in other organs, suggesting that they may play a role in the development of nonneural tissues as well. Finally, although STI1 and Vn are PrPC ligands, their expression was not altered in PrPC‐null mice. J. Comp. Neurol. 517:371–384, 2009. © 2009 Wiley‐Liss, Inc.
Anatomical localization of the effects of reproductive state, castration, and social milieu on cells immunoreactive for gonadotropin‐releasing hormone‐I in male European starlings (Sturnus vulgaris)
Authors: Stevenson Tyler J. , Ball Gregory F. 
Published: July 2009

AbstractGonadotropin‐releasing hormone‐I (GnRH‐I) cells are localized primarily to the septopreoptic area (POA) and are responsible for regulating gonadotropin release from the anterior pituitary. Some songbird species exhibit dramatic seasonal variation in the number of detectable GnRH‐I immunoreactive cells, with higher numbers being observed during the breeding season. Here we investigated the anatomical distribution of GnRH‐I‐immunoreactive cells in male starlings that varied in response to manipulations of reproductive state, social context, and gonadal condition. We housed photostimulated, intact and castrated male starlings with a female or alone. Additionally, a fifth treatment group consisted of photorefractory males (i.e., in a nonreproductive state) housed alone. All photostimulated males had significantly greater numbers of GnRH‐I cells compared with photorefractory male starlings. There was a significant main effect of castration and social context. Castrated males had significantly greater numbers of GnRH‐I cells compared with intact males, and males housed in male‐female dyads also had greater numbers of GnRH‐I cells. Furthermore, the significant main effects of castration and social context were the result of an increase in GnRH‐I cell numbers specifically in the rostral and intermediate regions of the POA. These findings indicate that social context and hormonal milieu have profound effects on GnRH‐I immunoreactivity in addition to the previously described effects of reproductive state. These data provide novel insight into the environmental regulation of the hypothalamopituitary axis and suggest that gonadal hormones and female presence independently regulate GnRH‐I cells in specific regions of the POA in male starlings. J. Comp. Neurol. 517:146–155, 2009. © 2009 Wiley‐Liss, Inc.
Cortical connections of the visual pulvinar complex in prosimian galagos (Otolemur garnetti)
Authors: Wong Peiyan , Collins Christine E. , Baldwin Mary K.L. , Kaas Jon H. 
Published: July 2009

AbstractThe pulvinar complex of prosimian primates is not as architectonically differentiated as that of anthropoid primates. Thus, the functional subdivisions of the complex have been more difficult to determine. In the present study, we related patterns of connections of cortical visual areas (primary visual area, V1; secondary visual area, V2; and middle temporal visual area, MT) as well as the superior colliculus of the visual midbrain, with subdivisions of the pulvinar complex of prosimian galagos (Otolemur garnetti) that were revealed in brain sections processed for cell bodies (Nissl), cytochrome oxidase, or myelin. As in other primates, the architectonic methods allowed us to distinguish the lateral pulvinar (PL) and inferior pulvinar (PI) as major divisions of the visual pulvinar. The connection patterns further allowed us to divide PI into a large central nucleus (PIc), a medial nucleus (PIm), and a posterior nucleus (PIp). Both PL and PIc have separate topographic patterns of connections with V1 and V2. A third, posterior division of PI, PIp, does not appear to project to V1 and V2 and is further distinguished by receiving inputs from the superior colliculus. All these subdivisions of PI project to MT. The evidence suggests that PL of galagos contains a single, large nucleus, as in monkeys, and that PI may have only three subdivisions, rather than the four subdivisions of monkeys. In addition, the cortical projections of PI nuclei are more widespread than those in monkeys. Thus, the pulvinar nuclei in prosimian primates and anthropoid primates have evolved along somewhat different paths. J. Comp. Neurol. 517:493–511, 2009. © 2009 Wiley‐Liss, Inc.
Acute and chronic sectioning of fifth lumbar spinal nerve has equivalent effects on the primary afferents of sciatic nerve in rat spinal cord
Authors: Shehab Safa Aldeen S. 
Published: July 2009

AbstractThe mechanism of neuropathic pain may be associated with sprouting of uninjured primary afferents of peripheral nerves into regions of the spinal cord denervated through peripheral injury. However, this remains controversial. Therefore, the purpose of the present investigation was, first, to determine in detail the central distributions of the unmyelinated primary afferents of each of the L4, L5, and L6 components of sciatic nerve, then to assess the distribution of afferent sciatic terminals following acute and chronic injury to (L5) nerve. First, we injected isolectin B4 (IB4), into the sciatic nerves in three groups of rats, each of which had two of the three L4, L5, or L6 components ligated and cut, and the one remaining, uninjured. Although the terminal labelling found in the L5 segment of the spinal cord originated from the L5 component, some terminal labelling remained in cases when either the L4 or L6 component was intact. Second, tracers transported in predominantly unmyelinated (IB4 and WGA‐HRP) or myelinated (cholera toxin subunit B) nerves were injected into the sciatic nerve following acute or chronic (21‐day) injury restricted to the L5 component. In each case, the central distribution of nerve terminals in the spinal dorsal horn was equivalent following either acute or chronic injury to the L5 component. Consequently, these data provide no support for the suggestion that neuropathic pain in spinal ligation model results from uninjured L4 and L6 components sprouting to occupy sites vacated by the injured L5 component of the sciatic nerve. J. Comp. Neurol. 517:481–492, 2009. © 2009 Wiley‐Liss, Inc.
Localization of circadian clock protein BMAL1 in the photoperiodic signal transduction machinery in Japanese quail
Authors: Ikegami Keisuke , Katou Yasuhiro , Higashi Kumiko , Yoshimura Takashi 
Published: July 2009

AbstractThe circadian clock is a fundamental property of living organisms and is involved in seasonal (photoperiodic) time measurement. Among vertebrates, birds have multiple circadian pacemakers in the eye, the pineal gland, and the suprachiasmatic nucleus (SCN), and have highly sophisticated photoperiodic mechanisms. However, because the removal of these circadian pacemakers fails to abolish the photoperiodic response, the existence of another “photoperiodic clock” has been suggested. Recent studies have revealed that the mediobasal hypothalamus (MBH) and the adjacent pars tuberalis (PT) of the pituitary gland constitute key components of the photoperiodic signal transduction machinery. In the present study, we generated a polyclonal antibody against the chicken circadian clock protein BMAL1 to examine BMAL1 distribution in the Japanese quail brain by using immunohistochemistry. BMAL1‐like immunoreactivity (lir) was confirmed in the pineal gland and the medial SCN, which are critical circadian pacemakers. We also observed strong immunoreactivity in the MBH, including the ependymal cells (ECs), the infundibular nucleus (IN), the median eminence (ME), and the adjacent PT. Furthermore, semiquantitative analysis suggested that BMAL1‐lir shows daily fluctuation in these regions. It is possible that circadian clocks in the photoperiodic signal transduction machinery such as the PT and the EC may be involved in the regulation of photoperiodism. J. Comp. Neurol. 517:397–404, 2009. © 2009 Wiley‐Liss, Inc.
Quantification of the three‐dimensional morphology of coincidence detector neurons in the medial superior olive of gerbils during late postnatal development
Authors: Rautenberg Philipp L. , Grothe Benedikt , Felmy Felix 
Published: July 2009

AbstractIn the mammalian medial superior olive (MSO), neurons compute the azimuthal location of sound sources by temporally precise coincidence detection. It is assumed that the dendritic morphology of MSO neurons plays a crucial role in this computational process. However, few quantitative data about the morphology of these neuronal coincidence detectors are available, limiting theoretical approaches. Such a quantitative morphological description of neurons of the mammalian MSO would also allow a comparative analysis with its avian analog, the nucleus laminaris. We used single‐cell electroporation, microscopic reconstruction, and compartmentalization to extract anatomical parameters of MSO neurons and quantitatively describe their morphology and development between postnatal day 9 and 36. We found that developmental refinement occurs until P27, generating morphologically compact, cylinder‐like cells with axons originating from the soma. The complexity of higher order dendrites decreases between postnatal days 9 and 21. This decrease in dendritic complexity is judged from counting and analyzing the location of dendritic branches and determining the distribution of the surface area and total length of neurons. During this developmental period, the average length of terminal branches increases about twofold, indicating an elimination of predominantly small branches. The cell volume increases more than 1.5‐fold between P9 and P27, a change that can be attributed to an increase in dendritic diameter during this developmental period. The developmental profile of the morphology of MSO neurons obtained indicates that maturation is reached 2 weeks after hearing onset. J. Comp. Neurol. 517:385–396, 2009. © 2009 Wiley‐Liss, Inc.
A novel somatostatin‐immunoreactive mossy fiber pathway asssociated with HSP25‐immunoreactive purkinje cell stripes in the mouse cerebellum
Authors: Armstrong C.L. , Chung S.‐H. , Armstrong J.N. , Hochgeschwender U. , Jeong Y.‐G. , Hawkes R. 
Published: July 2009

AbstractSomatostatin 28 immunoreactivity (Sst28‐ir) identifies a specific subset of mossy fiber terminals in the adult mouse cerebellum. By using double‐labeling immunohistochemistry, we determined that Sst28‐ir is associated with presynaptic mossy fiber terminal rosettes, and not Purkinje cells, Golgi cells, or unipolar brush cells. Sst28‐ir mossy fibers are restricted to the central zone (lobules VI/VII) and nodular zone (lobules IX, X) of the vermis, and the paraflocculus and flocculus. Within each transverse zone the mossy fiber terminal fields form a reproducible array of parasagittal stripes. The boundaries of Sst28‐ir stripes align with a specific array of Purkinje cell stripes revealed by using immunocytochemistry for the small heat shock protein HSP25. In the cerebellum of the homozygousweavermouse, in which a subpopulation of HSP25‐ir Purkinje cells are located ectopically, the corresponding Sst28‐ir mossy fiber projection is also ectopic, suggesting a role for a specific Purkinje cell subset in afferent pattern formation. Likewise, in thescramblermutant mouse, Sst28‐ir mossy fibers show a very close association with HSP25‐ir Purkinje cell clusters. HSP25 itself does not appear to be critical for normal patterning, however: in the KJR mouse, which does not express cerebellar HSP25, Sst28 expression appears to be normal. Likewise, the Purkinje cell patterning antigens zebrin II and HSP25 are expressed normally in both Sst‐ and Sst‐receptor knockout mice, suggesting that somatostatinergic transmission is not necessary for Purkinje cell stripe formation. J. Comp. Neurol. 517:524–538, 2009. © 2009 Wiley‐Liss, Inc.
Mapping of Wnt, frizzled, and Wnt inhibitor gene expression domains in the avian otic primordium
Authors: Sienknecht Ulrike J. , Fekete Donna M. 
Published: July 2009

AbstractWnt signaling activates at least three different pathways involved in development and disease. Interactions of secreted ligands and inhibitors with cell‐surface receptors result in the activation or regulation of particular downstream intracellular cascades. During the developmental stages of otic vesicle closure and beginning morphogenesis, the forming inner ear transcribes a plethora of Wnt‐related genes. We report expression of 23 genes out of 25 tested in situ hybridization probes on tissue serial sections. Sensory primordia and Frizzled gene expression share domains, with Fzd1 being a continuous marker. Prospective nonsensory domains express Wnts, whose transcripts mainly flank prosensory regions. Finally, Wnt inhibitor domains are superimposed over both prosensory and nonsensory otic regions. Three Wnt antagonists, Dkk1, SFRP2, and Frzb are prominent. Their gene expression patterns partly overlap and change over time, which adds to the diversity of molecular microenvironments. Strikingly, prosensory domains express Wnts transiently. This includes: 1) the prosensory otic region of high proliferation, neuroblast delamination, and programmed cell death at stage 20/21 (Wnt3, ‐5b, ‐7b, ‐8b, ‐9a, and ‐11); and 2) sensory primordia at stage 25 (Wnt7a and Wnt9a). In summary, robust Wnt‐related gene expression shows both spatial and temporal tuning during inner ear development as the otic vesicle initiates morphogenesis and prosensory cell fate determination. J. Comp. Neurol. 517:751–764, 2009. © 2009 Wiley‐Liss, Inc.
Influence of Intermolecular NH⋅⋅⋅π Interactions on Molecular Packing and Field‐Effect Performance of Organic Semiconductors
Authors: Zhao Huaping , Jiang Lang , Dong Huanli , Li Hongxiang , Hu Wenping , Ong Beng S. 
Published: July 2009

AbstractCharge transport in organic semiconductors is strongly dependent on their molecular packing modes in the solid state. Therefore, understanding the relationship between molecular packing and charge transport is imperative, both experimentally and theoretically. However, so far, the fundamental effects of solid‐state packing and molecular interactions (e.g. NH⋅⋅⋅π) on charge transport need further elucidation. Herein, indolo[3,2‐b]carbazole (ICZ) and a derivative thereof are used as examples to approach this scientific target. An interesting insight obtained thereby is that NH⋅⋅⋅π interactions among ICZ molecules facilitate charge transport for higher mobility. Subtle changes in the of NH⋅⋅⋅π interactions can significantly influence both the molecular packing and the charge‐transport properties. Therefore, a method for exploiting intermolecular NH⋅⋅⋅π interactions would yield novel molecular systems with designable characteristics.
A new CMOS astable multivibrator and its nonlinear analysis
Authors: Buonomo A. 
Published: July 2009

AbstractWe present a nonlinear analysis of a new inductively tuned astable multivibrator obtained by connecting a timing inductor across a composite nonlinear resistor with a characteristic of N‐type, which is made up of the parallel connection of two complementary pairs of cross‐coupled MOS devices. Some possible practical applications of the circuit are also envisaged. Closed‐form expressions for the amplitude and the period of the periodic oscillation are derived in both cases when the circuit exhibits a relaxation oscillation and in the more difficult case when, due to the effect of parasitic capacitances of the devices, the circuit has an almost‐discontinuous relaxation oscillation with a nonzero switching time. The accuracy of the presented formulas, which are useful for both the analysis and design, is validated through circuit simulations and experimental results. Copyright © 2009 John Wiley & Sons, Ltd.
Quantitative mechanics of endothelial phagocytosis of silicon microparticles
Authors: Serda Rita E. , Gu Jianhua , Burks Jared K. , Ferrari Kim , Ferrari Chiara , Ferrari Mauro 
Published: July 2009

AbstractEndothelia, once thought of as a barrier to the delivery of therapeutics, is now a major target for tissue‐specific drug delivery. Tissue‐ and disease‐specific molecular presentations on endothelial cells provide targets for anchoring or internalizing delivery vectors. Porous silicon delivery vectors are phagocytosed by vascular endothelial cells. The rapidity and efficiency of silicon microparticle uptake lead us to delineate the kinetics of internalization. To discriminate between surface‐attached and ‐internalized microparticles, we developed a double fluorescent/FRET flow cytometric approach. The approach relies on quenching of antibody‐conjugated fluorescein isothiocyanate covalently attached to the microparticle surface by attachment of a secondary antibody labeled with an acceptor fluorophore, phycoerythrin. The resulting half‐time for microparticle internalization was 15.7 min, with confirmation provided by live confocal imaging as well as transmission electron microscopy. © 2009 International Society for Advancement of Cytometry
An efficient online‐battery aware geographic routing algorithm for wireless sensor networks
Authors: Watfa Mohamed , Yaghi Linda 
Published: July 2009

AbstractWireless sensor networks (WSNs) are being used in a wide variety of critical applications such as military and health‐care applications. Such networks, which are composed of sensor nodes with limited memory capacity, limited processing capabilities, and most importantly limited energy supply, require routing protocols that take into consideration these constraints. The aim of this paper is to provide an efficient power aware routing algorithm for WSNs that guarantees QOS and at the same time minimizes energy consumption by calculating the remaining battery capacity of nodes and taking advantage of the battery recovery process. We present an online‐battery aware geographic routing algorithm. To show the effectiveness of our approach, we simulated our algorithm in ns2 and compared it with greedy perimeter stateless routing for wireless networks and battery‐aware routing for streaming data transmissions in WSNs. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation of carboxy‐PEG‐PLA nanoparticles loaded with camptothecin and their body distribution in solid tumor–bearing mice
Authors: Ueki Kennichi , Onishi Hiraku , Sasatsu Masanaho , Machida Yoshiharu 
Published: July 2009

AbstractCarboxy‐polyethylene glycol‐poly(DL‐lactic acid) block copolymer was synthesized by reductive amination of carboxy‐polyethylene glycol‐amine and aldehyde‐ended poly(DL‐lactic acid). The obtained product, PA‐PEG‐CB, composed of pure carboxy‐polyethylene glycol‐poly(DL‐lactic acid) block copolymer and poly(DL‐lactic acid), was used to prepare nanoparticles loaded with camptothecin (CPT), designated CPT‐NP. CPT‐NP with 500–600 nm and approximately 1% (w/w) drug content were obtained by emulsification/evaporation, while nanoparticles with a drug content of only less than 0.1% (w/w) were prepared by dialysis. CPT‐NP produced by emulsification/evaporation were used for in vitro and in vivo studies. CPT‐NP released CPT gradually in phosphate‐buffered saline, pH 7.4, at 37°C over 48 h. Biodistribution profiles were compared between CPT‐NP and CPT solution after i.v. injection into mice bearing sarcoma 180 solid tumor. CPT‐NP retained CPT approximately 10 times more in plasma during the initial 8 h than CPT solution. The tumor level of CPT was more than 10 times higher with CPT‐NP for the observation period (24 h), though the CPT concentration in the liver and spleen was much higher with CPT‐NP. CPT‐NP may be useful for tumor localization of CPT. Drug Dev Res 70: 512–519, 2009. © 2009 Wiley‐Liss, Inc.
Regional expression of MTG genes in the developing mouse central nervous system
Authors: Alishahi Amin , Koyano‐Nakagawa Naoko , Nakagawa Yasushi 
Published: July 2009

AbstractMyeloid translocation gene (MTG) proteins are transcriptional repressors that are highly conserved across species. We studied the expression of three members of this gene family, MTGR1, MTG8, and MTG16 in developing mouse central nervous system by in situ hybridization. All of these genes are detected as early as embryonic day 11.5. Because these genes are known to be induced by proneural genes during neurogenesis, we analyzed the expression of MTG genes in relation to two proneural genes, Neurog2 (also known as Ngn2 or Neurogenin 2) and Ascl1 (also known as Mash1). While MTGR1 are generally expressed in regions that also express Neurog2, MTG8 and MTG16 expression is associated more tightly with that of Ascl1‐expressing neural progenitor cells. These results suggest the possibility that expression of MTG genes is differentially controlled by specific proneural genes during neurogenesis. Developmental Dynamics 238:2095–2102, 2009. © 2009 Wiley‐Liss, Inc.