bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Enrichment Confers Stress Resiliency to Social Defeat through an Infralimbic Cortex-Dependent Neuroanatomical Pathway
Authors: Lehmann Michael L. , Herkenham Miles
Published: April 2011

Enriched environmental (EE) housing dampens stress-induced alterations in neurobiological systems, promotes adaptability, and extinguishes submissive behavioral traits developed during social defeat stress (SD). In the present study, we hypothesized that enrichment before SD can confer stress resiliency and, furthermore, that neuronal activity in the prefrontal cortex (PFC) is requisite for this resiliency. To test these hypotheses, mice were housed in EE, standard (SE), or impoverished (IE) housing and then exposed to SD. EE conferred resilience to SD as measured in several behavioral tasks. EE-housed mice expressed elevated FosB/ΔFosB immunostaining in areas associated with emotional regulation and reward processing, i.e., infralimbic, prelimbic, and anterior cingulate cortices, amygdala, and nucleus accumbens, and this expression was mostly preserved in mice receiving EE followed by SD. In contrast, in SE- or IE-housed animals, SD increased maladaptive behaviors and greatly reduced FosB/ΔFosB staining in the forebrain. We tested the putative involvement of the PFC in mediating resilience by lesioning individual regions of the PFC either before or after EE housing and then exposing the mice to SD. We found that discrete lesions of the infralimbic but not prelimbic or cingulate cortex made before but not after EE abolished the behavioral resiliency to stress afforded by EE and attenuated FosB/ΔFosB expression in the accumbens and amygdala while increasing it in the paraventricular hypothalamic nucleus. These data suggest that pathological ventromedial PFC outputs to downstream limbic targets could predispose an individual to anxiety disorders in stressful situations, whereas enhanced ventromedial PFC outputs could convey stress resilience.
Nociceptive Steady-State Evoked Potentials Elicited by Rapid Periodic Thermal Stimulation of Cutaneous Nociceptors
Authors: Mouraux André , Iannetti Gian Domenico , Colon Elisabeth , Nozaradan Sylvie , Legrain Valery , Plaghki Leon
Published: April 2011

The periodic presentation of a sensory stimulus induces, at certain frequencies of stimulation, a sustained electroencephalographic response known as steady-state evoked potential (SS-EP). In the somatosensory, visual, and auditory modalities, SS-EPs are considered to constitute an electrophysiological correlate of cortical sensory networks resonating at the frequency of stimulation. In the present study, we describe and characterize, for the first time, SS-EPs elicited by the selective activation of skin nociceptors in humans. The stimulation consisted of 2.3-s-long trains of 16 identical infrared laser pulses (frequency, 7 Hz), applied to the dorsum of the left and right hand and foot. Two different stimulation energies were used. The low energy activated only C-nociceptors, whereas the high energy activated both Aδ- and C-nociceptors. Innocuous electrical stimulation of large-diameter Aβ-fibers involved in the perception of touch and vibration was used as control. The high-energy nociceptive stimulus elicited a consistent SS-EP, related to the activation of Aδ-nociceptors. Regardless of stimulus location, the scalp topography of this response was maximal at the vertex. This was noticeably different from the scalp topography of the SS-EPs elicited by innocuous vibrotactile stimulation, which displayed a clear maximum over the parietal region contralateral to the stimulated side. Therefore, we hypothesize that the SS-EPs elicited by the rapid periodic thermal activation of nociceptors may reflect the activation of a network that is preferentially involved in processing nociceptive input and may thus provide some important insight into the cortical processes generating painful percepts.
Intracellular ATP Influences Synaptic Plasticity in Area CA1 of Rat Hippocampus via Metabolism to Adenosine and Activity-Dependent Activation of Adenosine A1Receptors
Authors: zur Nedden Stephanie , Hawley Simon , Pentland Naomi , Hardie D. Grahame , Doney Alexander S. , Frenguelli Bruno G.
Published: April 2011

The extent to which brain slices reflect the energetic status of thein vivobrain has been a subject of debate. We addressed this issue to investigate the recovery of energetic parameters and adenine nucleotides in rat hippocampal slices and the influence this has on synaptic transmission and plasticity. We show that, although adenine nucleotide levels recover appreciably within 10 min of incubation, it takes 3 h for a full recovery of the energy charge (to ≥0.93) and that incubation of brain slices at 34°C results in a significantly higher ATP/AMP ratio and a threefold lower activity of AMP-activated protein kinase compared with slices incubated at room temperature. Supplementation of artificial CSF withd-ribose and adenine (Rib/Ade) increased the total adenine nucleotide pool of brain slices, which, when corrected for the influence of the dead cut edges, closely approachedin vivovalues. Rib/Ade did not affect basal synaptic transmission or paired-pulse facilitation but did inhibit long-term potentiation (LTP) induced by tetanic or weak theta-burst stimulation. This decrease in LTP was reversed by strong theta-burst stimulation or antagonizing the inhibitory adenosine A1receptor suggesting that the elevated tissue ATP levels had resulted in greater activity-dependent adenosine release during LTP induction. This was confirmed by direct measurement of adenosine release with adenosine biosensors. These observations provide new insight into the recovery of adenine nucleotides after slice preparation, the sources of loss of such compounds in brain slices, the means by which to restore them, and the functional consequences of doing so.
Mitochondrial Parkin Recruitment Is Impaired in Neurons Derived from Mutant PINK1 Induced Pluripotent Stem Cells
Authors: Seibler Philip , Graziotto John , Jeong Hyun , Simunovic Filip , Klein Christine , Krainc Dimitri
Published: April 2011

Genetic Parkinson disease (PD) has been associated with mutations inPINK1, a gene encoding a mitochondrial kinase implicated in the regulation of mitochondrial degradation. While the studies so far examined PINK1 function in non-neuronal systems or through PINK1 knockdown approaches, there is an imperative to examine the role of endogenous PINK1 in appropriate human-derived and biologically relevant cell models. Here we report the generation of induced pluripotent stem (iPS) cells from skin fibroblasts taken from three PD patients with nonsense (c.1366C>T; p.Q456X) or missense (c.509T>G; p.V170G) mutations in the PINK1 gene. These cells were differentiated into dopaminergic neurons that upon mitochondrial depolarization showed impaired recruitment of lentivirally expressed Parkin to mitochondria, increased mitochondrial copy number, and upregulation of PGC-1α, an important regulator of mitochondrial biogenesis. Importantly, these alterations were corrected by lentiviral expression of wild-type PINK1 in mutant iPS cell-derived PINK1 neurons. In conclusion, our studies suggest that fibroblasts from genetic PD can be reprogrammed and differentiated into neurons. These neurons exhibit distinct phenotypes that should be amenable to further mechanistic studies in this relevant biological context.
Ambient GABA-Activated Tonic Inhibition Sharpens Auditory Coincidence Detection via a Depolarizing Shunting Mechanism
Authors: Tang Zheng-Quan , Hoang Dinh Emilie , Shi Wei , Lu Yong
Published: April 2011

Tonic inhibition mediated by extrasynaptic GABAAreceptors (GABAARs) has emerged as a novel form of neural inhibition in the CNS. However, little is known about its presence and function in the auditory system. Using whole-cell recordings in brain slices, we identified a tonic current mediated by GABAARs containing the δ subunit in middle/high-characteristic-frequency neurons of the chicken nucleus laminaris, the first interaural time difference encoder that computes information for sound localization. This tonic conductance was activated by ambient concentrations of GABA released from synaptic vesicles. Furthermore, pharmacological manipulations of the conductance demonstrated its essential role in coincidence detection. Remarkably, this depolarizing tonic conductance was strongly inhibitory primarily because of its shunting effect. These results demonstrate a novel role for tonic inhibition in central auditory information processing.
Robo1 Regulates Semaphorin Signaling to Guide the Migration of Cortical Interneurons through the Ventral Forebrain
Authors: Hernández-Miranda Luis R. , Cariboni Anna , Faux Clare , Ruhrberg Christiana , Cho Jin Hyung , Cloutier Jean-François , Eickholt Britta J. , Parnavelas John G. , Andrews William D.
Published: April 2011

Cortical interneurons, generated predominantly in the medial ganglionic eminence, migrate around and avoid the developing striatum in the subpallium en route to the cortex. This is attributable to the chemorepulsive cues of class 3 semaphorins expressed in the striatal mantle and acting through neuropilin (Nrp1 and Nrp2) receptors expressed in these cells. Cortical interneurons also express Robo receptors, and we show here that in mice lacking Robo1, but not Robo2, these cells migrate aberrantly through the striatum.In vitroexperiments demonstrated that interneurons lacking Robo1 function are significantly less responsive to the effects of semaphorins. Failure to respond to semaphorin appears to be attributable to a reduction in Nrp1 and PlexinA1 receptors within these cells. Biochemical studies further demonstrated that Robo1 binds directly to Nrp1, but not to semaphorins, and this interaction is mediated by a region contained within its first two Ig domains. Thus, we show for the first time that Robo1 interacts with Nrp1 to modulate semaphorin signaling in the developing forebrain and direct the migration of interneurons through the subpallium and into the cortex.
Astrocytic Tissue Inhibitor of Metalloproteinase-1 (TIMP-1) Promotes Oligodendrocyte Differentiation and Enhances CNS Myelination
Authors: Moore Craig S. , Milner Richard , Nishiyama Akiko , Frausto Ricardo F. , Serwanski David R. , Pagarigan Roberto R. , Whitton J. Lindsay , Miller Robert H. , Crocker Stephen J.
Published: April 2011

Tissue inhibitor of metalloproteinase-1 (TIMP-1) is an extracellular protein and endogenous regulator of matrix metalloproteinases (MMPs) secreted by astrocytes in response to CNS myelin injury. We have previously reported that adult TIMP-1 knock-out (KO) mice exhibit poor myelin repair following demyelinating injury. This observation led us to hypothesize a role for TIMP-1 in oligodendrogenesis and CNS myelination. Herein, we demonstrate that compact myelin formation is significantly delayed in TIMP-1 KO mice, a situation that coincided with dramatically reduced numbers of white matter astrocytes in the developing CNS. Analysis of differentiation in CNS progenitor cells (neurosphere) cultures from TIMP-1 KO mice revealed a specific deficit of NG2+oligodendrocyte progenitor cells. Application of recombinant murine TIMP-1 (rmTIMP-1) to TIMP-1 KO neurosphere cultures evoked a dose-dependent increase in NG2+cell numbers, while treatment with GM6001, a potent broad-spectrum MMP inhibitor did not. Similarly, administration of rmTIMP-1 to A2B5+immunopanned oligodendrocyte progenitors significantly increased the number of differentiated O1+oligodendrocytes, while antisera to TIMP-1 reduced oligodendrocyte numbers. We also determined that A2B5+oligodendrocyte progenitors grown in conditioned media derived from TIMP-1 KO primary glial cultures resulted in reduced differentiation of mature O1+oligodendrocytes. Finally, we report that addition of rmTIMP-1 to primary glial cultures resulted in a dose-dependent proliferative response of astrocytes. Together, these findings describe a previously uncharacterized role for TIMP-1 in the regulation of oligodendrocytes and astrocytes during development and provide a novel function for TIMP-1 on myelination in the developing CNS.
Cocaine Hijacks σ1 Receptor to Initiate Induction of Activated Leukocyte Cell Adhesion Molecule: Implication for Increased Monocyte Adhesion and Migration in the CNS
Authors: Yao Honghong , Kim Keejun , Duan Ming , Hayashi Teruo , Guo Minglei , Morgello Susan , Prat Alexander , Wang John , Su Tsung-Ping , Buch Shilpa
Published: April 2011

Human immunodeficiency virus (HIV)-associated increase in monocyte adhesion and trafficking is exacerbated by cocaine abuse. The underlying mechanisms involve cocaine-mediated upregulation of adhesion molecules with subsequent disruption of the blood–brain barrier (BBB). Recently, a novel activated leukocyte cell adhesion molecule (ALCAM) has been implicated in leukocyte transmigration across the endothelium. We now show that upregulation of ALCAM in the brain endothelium seen in HIV+/cocaine drug abusers paralleled increased CD68 immunostaining compared with HIV+/no cocaine or uninfected controls, suggesting the important role of ALCAM in promoting leukocyte infiltration across the BBB. Furthermore, ALCAM expression was increased in cocaine-treated mice with concomitant increase in monocyte adhesion and transmigrationin vivo, which was ameliorated by pretreating with the neutralizing antibody to ALCAM, lending additional support to the role of ALCAM. This new concept was further confirmed byin vitroexperiments. Cocaine-mediated induction of ALCAM in human brain microvascular endothelial cells through the translocation of σ receptor to the plasma membrane, followed by phosphorylation of PDGF-β (platelet-derived growth factor-β) receptor. Downstream activation of mitogen-activated protein kinases, Akt, and NF-κB (nuclear factor-κB) pathways resulted in induced expression of ALCAM. Functional implication of upregulated ALCAM was confirmed using cell adhesion and transmigration assays. Neutralizing antibody to ALCAM ameliorated this effect. Together, these findings implicate cocaine-mediated induction of ALCAM as a mediator of increased monocyte adhesion/transmigration into the CNS.
A Role for Myosin Va in Cerebellar Plasticity and Motor Learning: A Possible Mechanism Underlying Neurological Disorder in Myosin Va Disease
Authors: Miyata Mariko , Kishimoto Yasushi , Tanaka Masahiko , Hashimoto Kouichi , Hirashima Naohide , Murata Yoshiharu , Kano Masanobu , Takagishi Yoshiko
Published: April 2011

Mutations of themyosin Vagene cause the neurological diseases Griscelli syndrome type 1 and Elejalde syndrome in humans anddilutephenotypes in rodents. To understand the pathophysiological mechanisms underlying the neurological disorders in myosin Va diseases, we conducted an integrated analysis at the molecular, cellular, electrophysiological, and behavioral levels using thedilute-neurological(d-n) mouse mutant. These mice manifest an ataxic gait and clonic seizures during postnatal development, but the neurological disorders are ameliorated in adulthood. We found that smooth endoplasmic reticulum (SER) rarely extended into the dendritic spines of Purkinje cells (PCs) of youngd-nmice, and there were few, if any, IP3receptors. Moreover, long-term depression (LTD) at parallel fiber–PC synapses was abolished, consistent with our previous observations in juvenile lethaldilutemutants. Youngd-nmice exhibited severe impairment of cerebellum-dependent motor learning. In contrast, adultd-nmice showed restoration of motor learning and LTD, and these neurological changes were associated with accumulation of SER and IP3receptors in some PC spines and the expression of myosin Va proteins in the PCs. RNA interference-mediated repression of myosin Va caused a reduction in the number of IP3receptor-positive spines in cultured PCs. These findings indicate that myosin Va function is critical for subsequent processes in localization of SER and IP3receptors in PC spines, LTD, and motor learning. Interestingly,d-nmice had defects of motor coordination from young to adult ages, suggesting that the role of myosin Va in PC spines is not sufficient for motor coordination.
Oligodendrocyte Progenitors Reversibly Exit the Cell Cycle and Give Rise to Astrocytes in Response to Interferon-γ
Authors: Tanner Daniel C. , Cherry Jonathan D. , Mayer-Pröschel Margot
Published: April 2011

Oligodendrocyte-type 2 astrocyte progenitor cells (O-2A/OPCs) populate the CNS and generate oligodendrocytes and astrocytesin vitroandin vivo. Understanding how O-2A/OPCs respond to their environment is crucial to understanding how these cells function in the CNS and how to best promote their therapeutic proliferation and differentiation. We show that interferon-γ (IFN-γ) was not toxic to highly purified perinatal or adult rat O-2A/OPCs. IFN-γ treatment led to downregulation of PDGFR-α (platelet-derived growth factor receptor-α) and Ki-67 and decreased self-renewal in clonal populations. IFN-γ also significantly increased the proportion of cells in the G0/G1phase of the cell cycle, decreased BrdU (5-bromo-2′-deoxyuridine) incorporation, and led to increased expression of the cell cycle inhibitors Rb and p27kip1. Although p27kip1expression was not necessary for IFN-γ-mediated quiescence, its upstream regulator IRF-1 was required. The quiescent state of O-2A/OPCs caused by IFN-γ was reversible as the withdrawal of IFN-γ allowed O-2A/OPCs to appropriately respond to both proliferation and differentiation signals. Differentiation into oligodendrocytes induced by either thyroid hormone or CNTF was also abrogated by IFN-γ. This inhibition was specific to the oligodendrocyte pathway, as O-2A/OPC differentiation into astrocytes was not inhibited. IFN-γ alone also led to the generation of GFAP-positive astrocytes in a subset of O-2A/OPCs. Together, these results demonstrate a reversible inhibitory effect of IFN-γ on O-2A/OPC proliferation with a concomitant generation of astrocytes. We propose that neuroinflammation involving increased IFN-γ can reduce progenitor numbers and inhibit differentiation, which has significant clinical relevance for injury repair, but may also contribute to the generation of astrocytes.
Different Pain, Different Brain: Thalamic Anatomy in Neuropathic and Non-Neuropathic Chronic Pain Syndromes
Authors: Gustin Sylvia M. , Peck Chris C. , Wilcox Sophie L. , Nash Paul G. , Murray Greg M. , Henderson Luke A.
Published: April 2011

Trigeminal neuropathic pain (TNP) and temporomandibular disorders (TMD) are thought to have fundamentally different etiologies. It has been proposed that TNP arises through damage to, or pressure on, somatosensory afferents in the trigeminal nerve, whereas TMD results primarily from peripheral nociceptor activation. Because some reports suggest that neuropathic pain is associated with changes in brain anatomy, it is possible that TNP is maintained by changes in higher brain structures, whereas TMD is not. The aim of this investigation is to determine whether changes in regional brain anatomy and biochemistry occur in both conditions. Twenty-one TNP subjects, 20 TMD subjects, and 36 healthy controls were recruited. Voxel-based morphometry of T1-weighted anatomical images revealed no significant regional gray matter volume change in TMD patients. In contrast, gray matter volume of TNP patients was reduced in the primary somatosensory cortex, anterior insula, putamen, nucleus accumbens, and the thalamus, whereas gray matter volume was increased in the posterior insula. The thalamic volume decrease was only seen in the TNP patients classified as having trigeminal neuropathy but not those with trigeminal neuralgia. Furthermore, in trigeminal neuropathy patients, magnetic resonance spectroscopy revealed a significant reduction in theN-acetylaspartate/creatine ratio, a biochemical marker of neural viability, in the region of thalamic volume loss. The data suggest that the pathogenesis underlying neuropathic and non-neuropathic pain conditions are fundamentally different and that neuropathic pain conditions that result from peripheral injuries may be generated and/or maintained by structural changes in regions such as the thalamus.
Orexin Gene Transfer into Zona Incerta Neurons Suppresses Muscle Paralysis in Narcoleptic Mice
Authors: Liu Meng , Blanco-Centurion Carlos , Konadhode RodaRani , Begum Suraiya , Pelluru Dheeraj , Gerashchenko Dmitry , Sakurai Takeshi , Yanagisawa Masashi , van den Pol Anthony N. , Shiromani Priyattam J.
Published: April 2011

Cataplexy, a sudden unexpected muscle paralysis, is a debilitating symptom of the neurodegenerative sleep disorder, narcolepsy. During these attacks, the person is paralyzed, but fully conscious and aware of their surroundings. To identify potential neurons that might serve as surrogate orexin neurons to suppress such attacks, the gene for orexin (hypocretin), a peptide lost in most human narcoleptics, was delivered into the brains of the orexin-ataxin-3 transgenic mouse model of human narcolepsy. Three weeks after the recombinant adenoassociated virus (rAAV)-mediated orexin gene transfer, sleep–wake behavior was assessed. rAAV-orexin gene delivery into neurons of the zona incerta (ZI), or the lateral hypothalamus (LH) blocked cataplexy. Orexin gene transfer into the striatum or in the melanin-concentrating hormone neurons in the ZI or LH had no such effect, indicating site specificity. In transgenic mice lacking orexin neurons but given rAAV-orexin, detectable levels of orexin-A were evident in the CSF, indicating release of the peptide from the surrogate neurons. Retrograde tracer studies showed that the amygdala innervates the ZI consistent with evidence that strong emotions trigger cataplexy. In turn, the ZI projects to the locus ceruleus, indicating that the ZI is part of a circuit that stabilizes motor tone. Our results indicate that these neurons might also be recruited to block the muscle paralysis in narcolepsy.
A Proactive Mechanism for Selective Suppression of Response Tendencies
Authors: Cai Weidong , Oldenkamp Caitlin L. , Aron Adam R.
Published: April 2011

While most research on stopping action examines how an initiated response is stopped when a signal occurs (i.e., reactively), everyday life also calls for a mechanism to prepare to stop a particular response tendency (i.e., proactively and selectively). We hypothesized that human subjects can prepare to stop a particular response by proactively suppressing that response representation in the brain. We tested this by using single-pulse transcranial magnetic stimulation and concurrent electromyography. This allowed us to interrogate the corticomotor excitability of specific response representations even before action ensued. We found that the motor evoked potential of the effector that might need to be stopped in the future was significantly reduced compared with when that effector was at rest. Further, this neural index of proactive and selective suppression predicted the subsequent selectivity with which the behavioral response was stopped. These results go further than earlier reports of reduced motor excitability when responses are stopped. They show that the control can be applied in advance (proactively) and also targeted at a particular response channel (selectively). This provides novel evidence for an active mechanism of suppression in the brain that is setup according to the subject's goals and even before action ensues.
Visual Search Demands Dictate Reliance on Working Memory Storage
Authors: Luria Roy , Vogel Edward K.
Published: April 2011

Previous research suggested that working memory (WM) does not play any significant role in visual search. In three experiments, we investigated the search difficulty and individual differences in WM capacity as determinants of WM involvement during visual search tasks, using both behavioral and electrophysiological markers [i.e., the contralateral delay activity (CDA), which is a marker for WM capacity allocation]. Human participants performed a visual search task that contained a target, neutral distractors, and a flanker distractor. Overall, we found that, as the search difficultly increased (as indicated by longer reaction times), so did the role of WM in performing the search task (as indicated by larger CDA amplitudes). Moreover, the results pinpoint a dissociation between the two types of factors that determined the WM involvement in the search process. Namely, individual differences in WM capacity and search difficulty independently affected the degree to which the search process relied on WM. Instead of showing a progressive role, individual differences in WM capacity correlated with the search efficiency in all search conditions (i.e., easy, medium, and difficult). Counterintuitively, individuals with high WM capacity generally relied less on WM during the search task.
Genomewide Analysis of Rat Barrel Cortex Reveals Time- and Layer-Specific mRNA Expression Changes Related to Experience-Dependent Plasticity
Authors: Vallès Astrid , Boender Arjen J. , Gijsbers Steef , Haast Roy A. M. , Martens Gerard J. M. , de Weerd Peter
Published: April 2011

Because of its anatomical organization, the rodent whisker-to-barrel system is an ideal model to study experience-dependent plasticity. Manipulation of sensory input causes changes in the properties of the barrels at the physiological, structural, and functional levels. However, much less is known about the molecular events underlying these changes. To explore such molecular events, we have used a genomewide approach to identify key genes and molecular pathways involved in experience-induced plasticity in the barrel cortex of adult rats. Given the natural tendency of rats to explore novel objects, exposure to an enriched environment (EE) was used to stimulate the activity of the whisker-to-barrel cortexin vivo. Microarray analysis at two different time points after EE revealed differential expression of genes encoding transcription factors, including nuclear receptors, as well as of genes involved in the regulation of synaptic plasticity, cell differentiation, metabolism, and, surprisingly, blood vessel morphogenesis. These expression differences reflect changes in somatosensory information processing because unilateral whisker clipping showed EE-induced differential expression patterns in the spared versus deprived barrel cortex. Finally,in situhybridization revealed cortical layer patterns specific for each selected gene. Together, the present study offers the first genomewide exploration of the key genes regulated by somatosensory stimulation in the barrel cortex and thus provides a solid experimental framework for future in-depth analysis of the mechanisms underlying experience-dependent plasticity.
Opposing Roles of Nucleus Accumbens Core and Shell Dopamine in the Modulation of Limbic Information Processing
Authors: Ito Rutsuko , Hayen Anja
Published: April 2011

The dopaminergic innervation of the nucleus accumbens (NAc) is implicated in the selection and integration of motivationally relevant corticolimbic information that governs behavioral output. However, it is unknown whether the dopaminergic innervations of two anatomically distinct subregions of the NAc, core and shell, have differential roles in this gating process, and whether dopaminergic mechanisms are important in regulating the balance of limbic control over appetitive behavior at the point of learning. Having previously shown that repeated systemic pretreatment with amphetamine disrupts the regulation of competing limbic control over appetitive behavior in mice, we hereby examined the effects of repeated pretraining intra-NAc shell or core microinfusions ofd-amphetamine, general dopamine (DA) receptor antagonistcis-flupenthixol, or vehicle solution (saline) upon a simultaneously acquired conditioned cue and place preference task in rats. Repeated infusions of amphetamine into the NAc shell and core had opposite effects on the acquisition of conditioned place preference by significantly enhancing and attenuating, respectively, hippocampal-dependent place conditioning. In contrast, direct infusions of flupenthixol into the NAc shell attenuated place conditioning, while NAc core flupenthixol infusions not only attenuated cue conditioning, but also enhanced conditioned place preference. These findings implicate the NAc shell DA as being necessary for enabling hippocampal-dependent spatial information to gain control over appetitive learning, and the NAc core DA as being important for allowing basolateral amygdala-dependent information to gain control over appetitive learning. It is further proposed that NAc core DA may be critical in regulating limbic information flow through the NAc shell.
Interplay of Chemical Neurotransmitters Regulates Developmental Increase in Electrical Synapses
Authors: Park Won-Mee , Wang Yongfu , Park Soodong , Denisova Janna V. , Fontes Joseph D. , Belousov Andrei B.
Published: April 2011

Coupling of neurons by electrical synapses (gap junctions) transiently increases in the mammalian CNS during development. We report here that the developmental increase in neuronal gap junction coupling and expression of connexin 36 (Cx36; neuronal gap junction protein) are regulated by an interplay between the activity of group II metabotropic glutamate receptors (mGluRs) and GABAAreceptors. Specifically, using dye coupling, electrotonic coupling, Western blots and small interfering RNA in the rat and mouse hypothalamus and cortexin vivoandin vitro, we demonstrate that activation of group II mGluRs augments, and inactivation prevents, the developmental increase in neuronal gap junction coupling and Cx36 expression. However, changes in GABAAreceptor activity have the opposite effects. The regulation by group II mGluRs is via cAMP/PKA-dependent signaling, and regulation by GABAAreceptors is via Ca2+/PKC-dependent signaling. Furthermore, the receptor-mediated upregulation of Cx36 requires a neuron-restrictive silencer element in theCx36gene promoter, and the downregulation involves the 3′-untranslated region of theCx36mRNA, as shown using reverse-transcription quantitative real-time PCR and luciferase reporter activity analysis. In addition, the methyl thiazolyl tetrazolium analysis indicates that mechanisms for the developmental increase in neuronal gap junction coupling directly control the death/survival mechanisms in developing neurons. Together, the results suggest a multitiered strategy for chemical synapses in developmental regulation of electrical synapses.
Adaptive Routenbeschreibungen für Navigationssysteme
Authors: Münter Daniel , Hussein Tim
Published: April 2011

In diesem Beitrag stellen wir ein Verfahren zur adaptiven Präsentation für Navigationsgeräte vor, welche auf semantischen Modellen basiert. Dabei reichern wir herkömmliche Routenbeschreibungen mit semantischen Informationen an und präsentieren dem Fahrer lediglich diejenigen Routenanweisungen, an denen er wirklich interessiert ist und blenden überfl üssige Anweisungen aus.
A Context-Aware Proactive Controller for Smart Environments
Authors: Krüger Frank , Ruscher Gernot , Bader Sebastian , Kirste Thomas
Published: April 2011

Controlling smart environments containing multiple devices is a challenging problem. In particular the definition of suitable interaction paradigms, which can be divided into implicit and explicit models. Here we introduce an implicit controller for smart environments that infers possible goals of the users and provides support by achieving them automatically. We use models of the environment and the user to automatically create this controller. The resulting system is purely reactive and can be executed in real time.
Relativer Vorteil im Unterhaltungserleben virtueller Welten – Eine empirische Analyse am Beispiel ”World of Warcraft“
Authors: Pannicke Danny , Zarnekow Rüdiger , Müller Sebastian
Published: April 2011

World of Warcraft ist seit mehreren Jahren Marktführer im Bereich der verteilten Online-Rollenspiele (MMORPG) mit inzwischen etwa 11,5 Millionen Benutzern weltweit. Die durchgeführte Studie leistet einen Beitrag zur Erklärung dieses beispiellosen Erfolgs. Dazu wird auf der Basis der Forschungsergebnisse zum Unterhaltungserleben im Kontext von Computerspielen ein Modell mit fünf Determinanten des relativen Vorteils entwickelt. Das entwickelte Modell wurde auf der Basis einer Stichprobe (N = 121) aktiver Nutzer überprüft. Im Ergebnis zeigt sich, dass der relative Vorteil von World of Warcraft insbesondere auf der Qualität der Rahmenhandlung basiert. Andere Aspekte, wie etwa die technische Qualität, haben demgegenüber für den relativen Vorteil eine untergeordnete Bedeutung. In der Konsequenz legt die Studie weitere Forschungsbemühungen zu den Wirkungszusammenhängen narrativer Elemente in virtuellen Welten nahe.
Neue Möglichkeiten des Mouse-Trackings: Automatisierte Mustererkennung erleichtert die Usability-Analyse
Authors: Erlbeck Helena
Published: April 2011

Die Methode des Mouse-Trackings ist in den letzten Jahren zunehmend bekannt und beliebt geworden und hat sich einen festen Platz neben traditionellen Usability testing-Methoden verdient. Das Aufzeichnen von Mausbewegungen ermöglicht das genaue Nachvollziehen einzelner Nutzersessions und sämtlicher Interaktionen innerhalb dieser Sessions. Diese bisher größtenteils manuelle Analyse wird nun auch durch neue Methoden der automatisierten Erkennung spezifi scher Interaktionsmuster ergänzt und verfeinert.
Vastagtű-biopsziás hengerből készített imprint citológia növeli a vékonytű-aspirációs citológia szenzitivitását emlőrákos betegekben
Authors: Dayal Sanjeev , Murray Juliette , Wilson Kate , Lannigan Alison
Published: April 2011

Background: Fine needle aspiration cytology (FNAC) can have high inadequate results. The main objective of this study was to validate the sensitivity of imprint cytology and compare it to that of FNAC across all levels of staff experience. Our other objective was to find out whether handling of a core biopsy to obtain an imprint slide affected its morphology so as to make histopathological reporting from that tissue difficult. This we thought could be of significance while trying to diagnose smaller cancers where just one core could contain tumour. Methods: Patients (n = 56) with a suspicious breast lump had fine needle aspiration (FNA) and core biopsy. The core biopsy used to prepare the two imprint cytology slides was sent separately for histopathology reporting. Results: Simultaneous imprint cytology from a core biopsy increased the sensitivity of cytology results by 12% compared to that of FNAC alone. In this series we found imprint cytology to have a sensitivity of 84%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 82.7%. The histopathologists did not report any distortion in tissue morphology so as to affect histological reporting of the core used. Conclusion: Since most patients will have a core biopsy to confirm invasive cancer and the technique of imprint cytology is easily performed, perhaps it should be more widely used especially in units where the sensitivity of FNA is low.
Irradiatiós enteritis sebészeti prevenciója: esetismertetés és az irodalom áttekintése
Authors: Teknős Dániel , Baranyai Zsolt , Sinkó Dániel , Jakab Ferenc
Published: April 2011

Absztrakt

A sugárzás okozta bélgyulladás az igen magas szövődményi és mortalitási ráta miatt a hasi és kismedencei radioterápia egyik legrettegettebb szövődménye. A kórkép megelőzésében elsősorban besugárzástervezési és sugártechnikai újításoknak köszönhetően sikerült jelentős eredményeket elérni. Ugyanakkor lehetőség van sebészeti beavatkozásokkal tovább csökkenteni az irradiatio okozta bélgyulladás előfordulásának gyakoriságát. 75 éves férfi betegünknél urothelialis carcinoma transuretralis resectiója történt. Az irradiatiós kezelés előtt a fixált vékonybélkacsok nagyobb sugárterhelésének kivédésére kétoldali lágyéksérve miatt Shouldice szerinti hasfali rekonstrukciót végeztük. A későbbiekben a beteg 55 Gy besugárzásban és két széria Carboplatin-kezelésben részesült. A kemoirradiatiós kezelést követően a betegnél nem alakult ki sugárzás okozta enteritis. Cikkünkben foglalkozunk az inguinalis hernioplasztika prevenciós szerepével irradiatiós enteritis kialakulásában. Esetünk kapcsán bemutatjuk a kórképpel kapcsolatos, korábban közölt sebészeti prevenciós eljárásokat.
Irradiatiót és pneumonectomiát követő hörgősipolyos empyema thoracis nyitott, vákuumtámogatott (VAC) kezelése thoraco-myoplastica után
Authors: Balogh Gábor , Garbera István , Ifj. Balogh Gábor , Pápai Székely Zsolt
Published: April 2011

Absztrakt

Hörgőrák miatt jobb felső tüdőlebeny resectióján átesett beteg kemoirradiatiós kezelésének szövődményeként tüdőfibrosis, fenyegető tüdőgangraena lépett fel. Jobb oldali pneumonectomiára kényszerültünk, amely után késői hörgőcsonkkinyílás, empyema alakult ki. Esetünk ismertetésével azt kívánjuk bemutatni, hogy súlyos iatrogén ártalommal járó onkoradiológiai kezelés milyen szövődményláncolatot idézett elő, és mik voltak azok a terápiás eszközök, amelyek 3 év után a beteg gyógyulásához vezettek.
Aplicação de AG3 e CPPU na qualidade da uva 'Itália' em Porto Feliz-SP
Authors: Rodrigues Alessandro , Araujo João Paulo Campos de , Girardi Eduardo Augusto , Scarpare Fabio Vale , Scarpare Filho João Alexio
Published: April 2011

A videira 'Itália' (Vitis vinifera L.) é a cultivar de uva fina para mesa mais consumida no Brasil. A qualidade dos cachos é uma característica fundamental, sendo o tamanho das bagas o componente mais valorizado pelos consumidores. Uma das alternativas para incrementar a qualidade das bagas é o uso de biorreguladores. Avaliaram-se, em três ciclos de produção, os efeitos de doses de ácido giberélico (AG3) isolado e associado com forchlorfenuron (CPPU), na qualidade dos cachos de uva Itália produzida em Porto Feliz-SP. A aplicação dos biorreguladores foi realizada aos 25 dias após o florescimento, em delineamento experimental inteiramente casualizado, em fatorial 4X4 (zero, 10; 20 e 30 mg L-1 AG3 X zero, 5; 10 e 15 mg L-1 CPPU), com oito repetições para o primeiro ciclo, e fatorial 3X3 (zero, 20 e 30 mg L-1 AG3 X zero, 10 e 20 mg L-1 CPPU) com dez repetições para o segundo e terceiro ciclos. A mistura de 20 mg L-1 de AG3 com 10 mg L-1 de CPPU promoveu o incremento do comprimento e do diâmetro das bagas sem prejuízo da massa dos cachos, melhorando sua qualidade, em Porto Feliz-SP. O uso de CPPU isoladamente acarretou em redução do teor de sólidos solúveis das bagas.
Desenvolvimento inicial de mudas de jatobazeiro do cerrado em Aquidauana-MS
Authors: Costa Edilson , Leal Paulo Ademar Martins , Rego Norton Hayd , Benatti Jarbas
Published: April 2011

A busca por uma alimentação saudável tem aumentado o consumo de frutas e hortaliças, proporcionando maior aceitação das fruteiras do cerrado no mercado. Visando à obtenção de mudas de qualidade, este trabalho avaliou a formação de mudas do jatobazeiro-do-cerrado em diferentes ambientes protegidos e substratos, na UEMS, Aquidauana, no período de novembro de 2008 a março de 2009. Foram utilizados três ambientes protegidos: estufa plástica de polietileno transparente, viveiro de tela de sombreamento e viveiro telado com malha termorrefletora; e seis substratos: solo, Plantmax®, fibra de coco fina, fibra de coco chips, vermiculita e composto orgânico. O delineamento experimental foi o inteiramente casualizado, com esquema de parcelas subdivididas (split-plot) e dez repetições. Houve interação entre ambiente de cultivo e substrato na formação de mudas de jatobá-do-cerrado. Na estufa agrícola, indica-se a utilização do Plantmax® e, nos telados, recomenda-se a vermiculita. O Plantimax® promoveu crescimento uniforme das mudas, em todos ambientes, especialmente na estufa agrícola. O substrato com 100% de composto orgânico não é indicado na formação de mudas de jatobá-do-cerrado. O Índice de Qualidade de Dickson é um bom indicador do padrão de qualidade das mudas.
Infestação da mosca-negra-dos-citros (Aleurocanthus woglumi Ashby) em pomares de citros, em sistemas de plantio convencional e agroflorestal
Authors: Silva Anderson Gonçalves Da , Boiça Junior Arlindo Leal , Farias Paulo Roberto Silva , Barbosa José Carlos
Published: April 2011

Objetivou-se com o presente trabalho avaliar a infestação da mosca-negra-dos-citros em pomares de citros, em sistemas de plantio convencional e agroflorestal. A área experimental está localizada no município de Capitão Poço-PA, onde foram realizadas 12 amostragens durante o período de setembro de 2008 a outubro de 2009, avaliando a presença ou a ausência da praga nas laranjeiras, em ambos os sistemas de produção. Pelos resultados obtidos, observou-se que o sistema de plantio agroflorestal apresentou maior incidência de plantas com presença de mosca-negra-dos-citros comparado ao convencional, houve influência da temperatura na regulação da população da praga, e precipitações elevadas reduziram o número de plantas com presença de A. woglumi.
Raleio químico na produção de tangerina 'Ponkan'
Authors: Cruz Maria do Céu Monteiro da , Ramos José Darlan , Moreira Rodrigo Amato , Marques Virna Braga
Published: April 2011

A prática do raleio em tangerineira 'Ponkan' é utilizada para aumentar o tamanho da fruta e assim obter melhores preços no mercado. O trabalho foi realizado com o objetivo de testar diferentes concentrações de Ethephon sobre o raleio químico de tangerina 'Ponkan', visando a reduzir o número de frutas por planta e melhorar a uniformidade das frutas remanescentes. Foram testadas cinco concentrações de Ethephon: 0; 150; 300; 450 e 600 mg L-1, em dois estádios de desenvolvimento das frutas: 30 mm e 40 mm de diâmetro em tangerineira 'Ponkan'. Foi utilizado o esquema fatorial 5 x 2, com quatro repetições, em blocos casualizados, sendo cinco concentrações de Ethephon e dois estádios de desenvolvimento das frutas. A aplicação de Ethephon promoveu a abscisão de frutas em todas as concentrações testadas. As concentrações a partir de 300 mg L-1 apresentaram maior eficiência no raleio. As frutas remanescentes apresentaram melhor uniformidade no tamanho, e isso favoreceu maior rendimento da produção comercial da tangerina 'Ponkan'.
Distribuição espacial de Phytophthora nicotianae e reação de cultivares de cebola ao fungo
Authors: Almeida F.A. , Barreto M. , Barbosa J.C. , Costa F.M.
Published: April 2011

A cultura da cebola vem se mostrando altamente suscetível ao ataque de Phytophthora nicotianae, com danos econômicos e alto custo de produção pelo uso excessivo de produtos químicos. O presente trabalho teve como objetivo avaliar a dependência espacial do patógeno por meio da Geoestatística e em seguida, testar a resistência de cultivares de cebola sob sistema convencional de cultivo ao fungo. Os experimentos foram conduzidos no campus da FCAV-UNESP. Para detectar a presença do fungo nas amostras de solo, foram coletadas e processadas em laboratório onde, discos de folhas de limão Siciliano (Citrus limonum) foram utilizados como "iscas" na suspensão do solo para contagem desses discos infectados. Logo após, na mesma unidade experimental, avaliou-se treze cultivares (Dom Victor, BZ 21; Princesa, Taiko, Óptima, BZ 50, Mercedes, Sunset, Duquesa, Gobi, Sirius, Colina e Superex) de cebola, num experimento com delineamento em blocos casualizados com quatro repetições. Foram feitas avaliações semanais, do transplantio até a colheita. Pelo modelo de semivariograma isotrópico esférico ajustado aos dados, os resultados demonstraram não haver dependência espacial, revelando que a área apresentava uma distribuição agregada do patógeno. Com o mapeamento pelo método de Krigagem ordinário em blocos, verificou-se maior incidência do fungo, entre os três primeiros canteiros localizados na baixadas, com uma redução gradual para o restante que apresentou menor declividade na área. Dentre as cultivares avaliadas quanto à resistência ao fungo - Mercedes, Princesa e Duquesa são altamente suscetíveis, e as demais, demonstraram baixa suscetibilidade ao patógeno nessa primeira avaliação de campo.
Incidência e severidade do mofo-cinzento-da-mamoneira sob diferentes temperaturas, períodos de molhamento e concentração de conídios
Authors: Sussel A.A.B. , Pozza E.A. , Castro H.A. , Lasmar E.B.C
Published: April 2011

Avaliou-se o efeito da temperatura (15, 20, 25 e 28ºC), do período de molhamento (0, 6, 12, 24, 48 e 72 horas) e da concentração de conídios (0, 1x10², 1x10³, 1x10(4), 1x10(5) e 1x10(6) conídios mL-1) na incidência e na severidade do mofo-cinzento (Amphobotrys ricini) em racemos de mamona (Ricinus communis). O efeito da concentração de conídios foi avaliado, fixando-se a temperatura em 25 ºC e o período de molhamento em 48 horas. Os efeito das temperaturas e dos períodos de molhamento foram avaliados fixando-se a concentração de conídios em 1x10(5) conídios mL-1. Foram mensurados a incidência de frutos com sintomas e a severidade em cada racemo. Foi calculada a área abaixo da curva do progresso da incidência (AACPI) e da severidade (AACPS) e os dados submetidos à análise de variância e regressão. Houve diferença significativa quanto à influência de diferentes concentrações de conídios, temperaturas e períodos de molhamento no progresso do mofo-cinzento-da-mamoneira, além de ocorrer interação significativa entre a temperatura e o período de molhamento. A incidência e a severidade do mofo-cinzento-da-mamoneira apresentaram acréscimos com a elevação da concentração de conídios até 10(5) conídios mL-1. A AACPI e a AACPS aumentaram com o incremento do período de molhamento e elevação da temperatura. Não houve manifestação de sintomas na ausência do molhamento foliar.
Diversidade fenotípica e patogênica de Colletotrichum, agente causal da antracnose em mangueira, e identificação de espécie
Authors: Serra I.M.R.S. , Coelho R.S.B. , Ferraz G.M.G. , Montarroyos A.V.V. , Silva D.S.
Published: April 2011

O presente trabalho teve como objetivo estudar a diversidade fenotípica e patogênica de 40 isolados de Colletotrichum obtidos de mangueira no Nordeste do Brasil e identificar diferentes espécies desse fitopatógeno, agente causal de antracnose, através da análise da seqüência da região ITS do rDNA. Quanto à caracterização morfológica e cultural, as colônias dos isolados apresentaram diversidade em relação à cor e aspecto, sendo mais comum à cor branco-cinza, característica de Colletotrichum gloeosporioides. Não foram observadas variações expressivas na morfologia dos 40 isolados. Os conídios apresentaram-se, predominantemente, hialinos e unicelulares, com formato variando de bastonete para cilíndrico. Todos os isolados produziram apressórios variados em formato e quantidade e apenas 10 isolados apresentaram setas. Para efeito do crescimento micelial e taxa de crescimento foi possível classificar os isolados em sete grupos. Vinte e dois isolados exibiram taxa de crescimento >10mm/dia, considerada típica da espécie C. gloeosporioides. Os isolados foram patogênicos em folhas destacadas de mangueira, induzindo sintomas de antracnose, na forma de manchas escuras levemente deprimidas, e apresentando variações quanto à agressividade. Na identificação específica, baseada na análise da seqüência ITS do DNA ribossomal, 36 isolados amplificaram com o oligonucleotídeos CgInt, específico para C. gloeosporioides e o ITS4, Os isolados CM1, CM4, CM5 e CM10, não amplificaram produtos para nenhum dos oligonucleotídeos específicos, sendo identificados como Colletotrichum spp. Os resultados desse trabalho demonstraram que isolados de Colletotrichum, obtidos de mangueira, apresentam ampla variabilidade morfofisiológica e patogênica. E que, possivelmente, existe mais de uma espécie de Colletotrichum que causa antracnose em mangueira no Nordeste do Brasil.