bluuebunny/crossref_metadata_2025 huggingface dataset:
Deprivation State Switches the Neurobiological Substrates Mediating Opiate Reward in the Ventral Tegmental Area
Authors: Nader Karim , van der Kooy Derek
Published: April 2018

The population of mesolimbic dopaminergic neurons is believed to be a primary site at which opiates produce their rewarding effects. Using an unbiased, counterbalanced place conditioning paradigm, we reexamined the contribution made by these cells to the rewarding properties of morphine. Rats were conditioned such that distinct environments were paired with an intra-ventral tegmental area (VTA) microinfusion of either 500 ng per 0.5 μl per side morphine or 0.5 μl per side sterile saline. Furthermore, rats were conditioned either previously drug-naive or while in a motivational state of opiate dependence and withdrawal. We report that pretreatment with the broad-spectrum dopamine antagonist α-flupentixol blocked the acquisition of conditioned place preferences for environments paired with morphine microinjections directly into the VTA in opiate-dependent and withdrawn, but not in previously drug-naive, rats. Lesions of the tegmental pedunculopontine nucleus (TPP) produced exactly the opposite pattern of results. TPP lesions blocked the acquisition of conditioned place preferences for environments paired with VTA morphine microinjections in previously drug-naive, but not in opiate-dependent and withdrawn, rats. These data double-dissociate two independent reward substrates within the VTA itself and suggest that deprivation state selects which of these two substrates will be active. Furthermore, these findings are the first to demonstrate a nondopaminergic substrate for reward within the VTA itself.
Unique Postsynaptic Signaling at the Hair Cell Efferent Synapse Permits Calcium to Evoke Changes on Two Time Scales
Authors: Sridhar T. S. , Brown M. C. , Sewell W. F.
Published: April 2018

The cholinergic efferent fibers to the outer hair cells (OHCs) of the mammalian cochlea suppress sound-evoked activity of the auditory nerve on two time scales via one nicotinic receptor. A rapid action (tens of milliseconds) is responsible for modulating auditory nerve responses to acoustic stimulation. A slower action (tens of seconds) may protect the ear from acoustic overstimulation. The rapid action is likely caused by calcium influx through the nicotinic receptor that leads to opening of calcium-activated potassium (KCa) channels, but the mechanism of the slower action has not been explained. To investigate this mechanism, we perfused the cochlea with agents that alter intracellular calcium release and uptake. Both fast and slow effects were enhanced by perfusion of the cochlea with ryanodine, an agonist of calcium-induced calcium release (CICR). Antagonists of sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA), cyclopiazonic acid, and thapsigargin (1) selectively enhanced the magnitude of slow effects, (2) prevented the diminution of slow effects with continued efferent stimulation, and (3) spread the range of frequencies over which slow effects were observed. We propose that the slow effect is attributable to release of calcium from the subsurface cisterna of the OHC, perhaps triggered by CICR from the synaptic cisterna; the two time scales of efferent action may result from the unique arrangement of the two cisternae in the baso-lateral region of the OHC.
The Mammalian Brain High-Affinity l-Proline Transporter Is Enriched Preferentially in Synaptic Vesicles in a Subpopulation of Excitatory Nerve Terminals in Rat Forebrain
Authors: Renick Stephani E. , Kleven Dan T. , Chan June , Stenius Katinka , Milner Teresa A. , Pickel Virginia M. , Fremeau Robert T.
Published: April 2018

The expression of a brain-specific high-affinity Na+-dependent (and Cl−-dependent)l-proline transporter (PROT) in subpopulations of putative glutamatergic neurons in mammalian brain suggests a physiological role for this carrier in excitatory neurotransmission (Fremeau et al., 1992). To gain insights into potential sites where PROT may function, we used a C-terminal domain antipeptide antibody to determine the regional distribution and subcellular localization of PROT in rat forebrain. PROT immunoreactivity was seen in processes having a regional light microscopic distribution comparable to that of known glutamatergic projections within the cortex, caudate putamen nucleus (CPN), hippocampal formation, and other forebrain regions. In all regions examined by electron microscopy (cortex, CPN, and the stratum oriens of CA1), PROT labeling was observed primarily within subpopulations of axon terminals forming asymmetric excitatory-type synapses. Immunogold labeling for PROT was detected in close contact with membranes of small synaptic vesicles (SSVs) and more rarely with the plasma membrane in these axon terminals. Subcellular fractionation studies confirmed the preferential distribution of PROT to synaptic vesicles. The topology of PROT in synaptic vesicles was found to be inverted with respect to the plasma membrane, suggesting that PROT-containing vesicles are generated by a process involving endocytosis from the plasma membrane. Because PROT lacks any of the known characteristics of other vesicular transporters, these results suggest that certain excitatory terminals have a reserve pool of PROT associated with SSVs. The delivery of PROT to the plasma membrane by exocytosis could play a critical role in the plasticity of certain glutamatergic pathways.
Pituitary Adenylate Cyclase-Activating Polypeptide and Melatonin in the Suprachiasmatic Nucleus: Effects on the Calcium Signal Transduction Cascade
Authors: Kopp Michael D. A. , Schomerus Christof , Dehghani Faramarz , Korf Horst-Werner , Meissl Hilmar
Published: April 2018

The suprachiasmatic nucleus (SCN) harbors an endogenous oscillator generating circadian rhythms that are synchronized to the external light/dark cycle by photic information transmitted via the retinohypothalamic tract (RHT). The RHT has recently been shown to contain pituitary adenylate cyclase-activating polypeptide (PACAP) as neurotransmitter/neuromodulator. PACAPergic effects on cAMP-mediated signaling events in the SCN are restricted to distinct time windows and sensitive to melatonin. In neurons isolated from the SCN of neonatal rats we investigated by means of the fura-2 technique whether PACAP and melatonin also influence the intracellular calcium concentration ([Ca2+]i). PACAP elicited increases of [Ca2+]iin 27% of the analyzed neurons, many of which were also responsive to the RHT neurotransmitters glutamate and/or substance P. PACAP-induced changes of [Ca2+]iwere independent of cAMP, because they were not mimicked by forskolin or 8-bromo-cAMP. PACAP caused G-protein- and phospholipase C-mediated calcium release from inositol-trisphosphate-sensitive stores and subsequent protein kinase C-mediated calcium influx, demonstrated by treatment with GDP-β-S, neomycin, U-73122, calcium-free saline, thapsigargin, bisindolylmaleimide, and chelerythrine. The calcium influx was insensitive to antagonists of voltage-gated calcium channels of the L-, N-, P-, Q- and T-type (diltiazem, nifedipine, verapamil, ω-conotoxin, ω-agatoxin, amiloride). Immunocytochemical characterization of the analyzed cells revealed that >50% of the PACAP-sensitive neurons were GABA-immunopositive. Our data demonstrate that in the SCN PACAP affects the [Ca2+]i, suggesting that different signaling pathways (calcium as well as cAMP) are involved in PACAPergic neurotransmission or neuromodulation. Melatonin did not interfere with calcium signaling, indicating that in SCN neurons the hormone primarily affects the cAMP signaling pathway.
Prenatal Development of Retinogeniculate Axons in the Macaque Monkey during Segregation of Binocular Inputs
Authors: Snider Cara J. , Dehay Colette , Berland Michel , Kennedy Henry , Chalupa Leo M.
Published: April 2018

In the fetal monkey the projections from the two eyes are initially completely intermingled within the dorsal lateral geniculate nucleus (DLGN) before separating into eye-specific layers (Rakic, 1976). To assess the cellular basis of this developmental process, we examined the morphological properties of individual retinogeniculate axons in prenatal monkeys of known gestational ages. The period studied spanned the time from when binocular overlap has been reported to be maximum, circa embryonic (E) day 77 through E112, when the segregation process is already largely completed in the caudal portion of the nucleus. Retinogeniculate fibers were labeled by making small deposits of DiI crystals into the fixed optic tract. After adequate time was allowed for diffusion of the tracer, fibers were visualized by confocal microscopy, and morphometric measures were made from photomontages. This revealed that retinogeniculate fibers in the embryonic monkey undergo continuous growth and elaboration during binocular overlap and subsequent segregation. Importantly, very few side-branches were found along the preterminal axon throughout the developmental period studied. Thus, restructuring of retinogeniculate fibers does not underlie the formation of eye-restricted projections in the primate. Rather, the results support the hypothesis that binocular segregation in the embryonic monkey is caused by the loss of retinal fibers that initially innervate inappropriate territories (Rakic, 1986).
Effects of Attention on Orientation-Tuning Functions of Single Neurons in Macaque Cortical Area V4
Authors: McAdams Carrie J. , Maunsell John H. R.
Published: April 2018

We examined how attention affected the orientation tuning of 262 isolated neurons in extrastriate area V4 and 135 neurons in area V1 of two rhesus monkeys. The animals were trained to perform a delayed match-to-sample task in which oriented stimuli were presented in the receptive field of the neuron being recorded. On some trials the animals were instructed to pay attention to those stimuli, and on other trials they were instructed to pay attention to other stimuli outside the receptive field. In this way, orientation-tuning curves could be constructed from neuronal responses collected in two behavioral states: one in which those stimuli were attended by the animal and one in which those stimuli were ignored by the animal. We fit Gaussians to the neuronal responses to twelve different orientations for each behavioral state. Although attention enhanced the responses of V4 neurons (median 26% increase) and V1 neurons (median 8% increase), selectivity, as measured by the width of its orientation-tuning curve, was not systematically altered by attention. The effects of attention were consistent with a multiplicative scaling of the driven response to all orientations. We also found that attention did not cause systematic changes in the undriven activity of the neurons.
UV- and Midwave-Sensitive Cone-Driven Retinal Responses of the Mouse: A Possible Phenotype for Coexpression of Cone Photopigments
Authors: Lyubarsky A. L. , Falsini B. , Pennesi M. E. , Valentini P. , Pugh E. N.
Published: April 2018

Molecular biological, histological and flicker electroretinographic results have established that mice have two cone photopigments, one peaking near 350 nm (UV-cone pigment) and a second near 510 nm [midwave (M)-cone pigment]. The goal of this investigation was to measure the action spectra and absolute sensitivities of the UV-cone- and M-cone-driven b-wave responses of C57BL/6 mice. To achieve this goal, we suppressed rod-driven signals with steady or flashed backgrounds and obtained intensity–response relations for cone-driven b-waves elicited by narrowband flashes between 340 and 600 nm. The derived cone action spectra can be described as retinal1pigments with peaks at 355 and 508 nm. The UV peak had an absolute sensitivity of ∼8 nV/(photon μm2) at the cornea, approximately fourfold higher than the M peak. In an attempt to isolate UV-cone-driven responses, it was discovered that an orange conditioning flash (λ > 530 nm) completely suppressed ERG signals driven by both M pigment- and UV pigment-containing cones. Analysis showed that the orange flash could not have produced a detectable response in the UV-cone pathway were their no linkage between M pigment- and UV pigment-generated signals. Because cones containing predominantly the UV and M pigments have been shown to be located largely in separate parts of the mouse retina (Szel et al., 1992), the most probable linkage is coexpression of M pigment in cones primarily expressing UV pigment. New histological evidence supports this interpretation (Gloesman and Ahnelt, 1998). Our data are consistent with an upper bound of ∼3% coexpression of M pigment in the cones that express mostly the UV pigment.
Contributions of Social Cues and Photoperiod to Seasonal Plasticity in the Adult Avian Song Control System
Authors: Tramontin Anthony D. , Wingfield John C. , Brenowitz Eliot A.
Published: April 2018

In seasonally breeding birds, the vernal growth of the song system is thought to result primarily from increased daylength and the associated increase in circulating testosterone. Other environmental factors such as social cues between mates influence the timing of reproduction, but less is known about how social cues might affect the song system and song behavior. We used white-crowned sparrows (Zonotrichia leucophrys gambelii) to test the hypothesis that the presence of a female in breeding condition influences song nuclei and song behavior of adult males. There were four treatment groups: (1) eight males housed individually in the same room on long days and paired with estradiol-implanted females; (2) eight males housed similarly on long days but without females; (3) four males isolated on long days; and (4) four males isolated on short days. The volumes of two song nuclei, HVc and RA, were significantly larger in males housed with females than in any other treatment group. Males isolated on short days had smaller HVc, RA, and area X volumes than all other groups. The volumes of Rt (a thalamic nucleus not involved in song) and the telencephalon did not differ among groups. Plasma androgen levels did not differ among the three long-day, social treatment groups at the times sampled, but were lower in the short-day isolates. Males paired with females sang at a higher maximum rate than males housed together, who sang at a higher rate than long-day isolates. These results suggest that seasonal plasticity in the adult song system is influenced by social cues.
Identification of the Receptor Subtype Involved in the Analgesic Effect of Neurotensin
Authors: Dubuc Isabelle , Sarret Philippe , Labbé-Jullié Catherine , Botto Jean-Marie , Honoré Eric , Bourdel Elisabeth , Martinez Jean , Costentin Jean , Vincent Jean-Pierre , Kitabgi Patrick , Mazella Jean
Published: April 2018

The neuropeptide neurotensin (NT) elicits hypothermic and naloxone-insensitive analgesic responses after brain injection. Recent pharmacological evidence obtained with NT agonists and antagonists suggests that these effects are mediated by a receptor distinct from the initially cloned high-affinity NT receptor (NTR1). The recent cloning of a second NT receptor (NTR2) prompted us to evaluate its role in NT-induced analgesia. Intracerebroventricular injections in mice of two different antisense oligodeoxynucleotides from the NTR2 markedly decreased NTR2 mRNA and protein and reduced NT-induced analgesia. This effect was specific, because NTR1 levels were unaffected, and sense or scramble oligodeoxynucleotides had no effect. Structure–activity studies revealed a close correlation between the analgesic potency of NT analogs and their affinity for the NTR2 and disclosed potent and selective agonists of this receptor. These data confirm that NTR1 is involved in the NT-elicited turning behavior and demonstrate that the NTR2 mediates NT-induced analgesia.
Hypoxia-Induced Silencing of NMDA Receptors in Turtle Neurons
Authors: Bickler Philip E. , Donohoe Paul H. , Buck Leslie T.
Published: April 2018

Hypoxia-induced suppression of NMDA receptors (NMDARs) in western painted turtle (Chrysemys picta) cortical neurons may be critical for surviving months of anoxic dormancy. We report that NMDARs are silenced by at least three different mechanisms operating at different times during anoxia. In pyramidal neurons from cerebrocortex, 1–8 min anoxia suppressed NMDAR activity (Ca2+influx and open probability) by 50–60%. This rapid decrease in receptor activity was controlled by activation of phosphatase 1 or 2A but was not associated with an increase in [Ca2+]i. However, during 2 hr of anoxia, [Ca2+]iin cerebrocortical neurons increased by 35%, and suppression of NMDARs was predicted by the increase of [Ca2+]iand controlled by calmodulin. An additional mechanism of NMDAR silencing, reversible removal of receptors from the cell membrane, was found in cerebrocortex of turtles remaining anoxic at 3°C for 3–21 d. When suppression of NMDARs was prevented with phosphatase inhibitors, tolerance of anoxia was lost. Silencing of NMDARs is thus critical to the remarkable ability ofC. pictato tolerate life without oxygen.
GABAAReceptor ε and θ Subunits Display Unusual Structural Variation between Species and Are Enriched in the Rat Locus Ceruleus
Authors: Sinkkonen Saku T. , Hanna Michael C. , Kirkness Ewen F. , Korpi Esa R.
Published: April 2018

Previously, GABAAreceptor ε and θ subunits have been identified only in human. Here, we describe properties of the ε and θ subunit genes from mouse and rat that reveal an unusually high level of divergence from their human homologs. In addition to a low level of amino acid sequence conservation (∼70%), the rodent ε subunit cDNAs encode a unique Pro/Glx motif of ∼400 residues within the N-terminal extracellular domain of the subunits. Transcripts of the rat ε subunit were detected in brain and heart, whereas the mouse θ subunit mRNA was detectable in brain, lung, and spleen by Northern blot analysis.In situhybridization revealed a particularly strong signal for both subunit mRNAs in rat locus ceruleus in which expression was detectable from the first postnatal day. Lower levels of coexpression were also detected in other brainstem nuclei and in the hypothalamus. However, the expression pattern of θ subunit mRNA was more widespread than that of ε subunit, being found also in the cerebral cortex of rat pups. In contrast to primate brain, neither subunit was expressed in the hippocampus or substantia nigra. The results indicate that GABAAreceptor ε and θ subunits are evolving at a much faster rate than other known GABAAreceptor subunits and that their expression patterns and functional properties may differ significantly between species.
Evidence for Seeding of β-Amyloid by Intracerebral Infusion of Alzheimer Brain Extracts in β-Amyloid Precursor Protein-Transgenic Mice
Authors: Kane Michael D. , Lipinski William J. , Callahan Michael J. , Bian Feng , Durham Robert A. , Schwarz Roy D. , Roher Alex E. , Walker Lary C.
Published: April 2018

Many neurodegenerative diseases are associated with the abnormal sequestration of disease-specific proteins in the brain, but the events that initiate this process remain unclear. To determine whether the deposition of the β-amyloid peptide (Aβ), a key pathological feature of Alzheimer's disease (AD), can be inducedin vivo, we infused dilute supernatants of autopsy-derived neocortical homogenates from Alzheimer's patients unilaterally into the hippocampus and neocortex of 3-month-old β-amyloid precursor protein (βAPP)-transgenic mice. Up to 4 weeks after the infusion there was no Aβ-deposition in the brain; however, after 5 months, the AD-tissue-injected hemisphere of the transgenic mice had developed profuse Aβ-immunoreactive senile plaques and vascular deposits, some of which were birefringent with Congo Red. There was limited deposition of diffuse Aβ also in the brains of βAPP-transgenic mice infused with tissue from an age-matched, non-AD brain with mild β-amyloidosis, but none in mice receiving extract from a young control case. Aβ deposits also were not found in either vehicle-injected or uninjected transgenic mice or in any nontransgenic mice. The results show that cerebral β-amyloid can be seededin vivoby a single inoculation of dilute AD brain extract, demonstrating a key pathogenic commonality between β-amyloidosis and other neurodegenerative diseases involving abnormal protein polymerization. The paradigm can be used to clarify the conditions that initiatein vivoβ-amyloidogenesis in the brain and may yield a more authentic animal model of Alzheimer's disease and other neurodegenerative disorders.
Morphology and Growth Patterns of Developing Thalamocortical Axons
Authors: Skaliora Irini , Adams Richard , Blakemore Colin
Published: April 2018

It is increasingly evident that the actions of guidance factors depend critically on the cellular and molecular context in which they operate. For this reason we examined the growth cone morphology and behavior of thalamic fibers in the relatively natural environment of a slice preparation containing the entire pathway from thalamus to cortex. Axons were labeled with DiI crystals and imaged with a laser-scanning confocal microscope for up to 8 hr. Their behavior was analyzed in terms of morphology, extension rates, shape of trajectory, frequency of branching, and percentage of time spent in advance, pause, and retraction. Thalamic fibers had distinct and stereotyped growth patterns that related closely to their position; within the striatum growth cones were small and elongated, rarely extending filopodia or side branches. Axons grew quickly, in straight trajectories, with minimal pauses or retractions. When they reached the ventral intermediate zone, axons slowed down, often coming to a complete stop for up to several hours, and their growth cones became larger and more complex. During pauses there were continuous extensions and retractions of filopodia and/or side branches. When advance resumed, it was often to a different direction. These results demonstrate consistent regional variations in growth patterns that identify an unexpected decision region for thalamic axons. They provide the basis for examining the roles of guidance cues in an accessible yet intact preparation of the thalamocortical pathway and allow for an evaluation of previously suggested pathfinding mechanisms.
Neurodegeneration inLurcherMice Occurs via Multiple Cell Death Pathways
Authors: Doughty Martin L. , De Jager Philip L. , Korsmeyer Stanley J. , Heintz Nathaniel
Published: April 2018

Lurcher(Lc) is a gain-of-function mutation in the δ2 glutamate receptor (GRID2) that results in the cell-autonomous death of cerebellar Purkinje cells in heterozygouslurcher(+/Lc) mice. This in turn triggers the massive loss of afferent granule cells during the first few postnatal weeks. Evidence suggests that the death of Purkinje cells as a direct consequence of GRID2Lcactivation and the secondary death of granule cells because of target deprivation occur by apoptosis. We have used mice carryingnullmutations of both theBaxandp53genes to examine the roles of these genes in cell loss inlurcheranimals. The absence ofBaxdelayed Purkinje cell death in response to theGRID2Lcmutation and permanently rescued the secondary death of granule cells. In contrast, thep53deletion had no effect on either cell death pathway. Our results demonstrate that target deprivation induces aBax-dependent,p53-independent cell death response in cerebellar granule cellsin vivo.In contrast,Baxplays a minor role in GRID2Lc-mediated Purkinje cell death.
Neuronal Basic Helix-Loop-Helix Proteins (NEX and BETA2/Neuro D) Regulate Terminal Granule Cell Differentiation in the Hippocampus
Authors: Schwab Markus H. , Bartholomae Angelika , Heimrich Bernd , Feldmeyer Dirk , Druffel-Augustin Silke , Goebbels Sandra , Naya Frank J. , Zhao Shanting , Frotscher Michael , Tsai Ming-Jer , Nave Klaus-Armin
Published: April 2018

The transcription factors neuronal helix-loop-helix protein (NEX)/mammalian atonal homolog 2 (Math-2), BETA2/neuronal determination factor (NeuroD), and NeuroD-related factor (NDRF)/NeuroD2 comprise a family ofDrosophilaatonal-related basic helix-loop-helix (bHLH) proteins with highly overlapping expression in the developing forebrain. The ability of BETA2/NeuroD and NDRF to convert ectodermal cells into neurons after mRNA injection intoXenopusoocytes suggested a role in specifying neuronal cell fate. However, neuronal bHLH genes are largely transcribed in CNS neurons, which are fully committed. Here we analyze a defect in mice lacking BETA2/NeuroD, and in NEX*BETA2/NeuroD double mutants, demonstrating that bHLH proteins are requiredin vivofor terminal neuronal differentiation. Most strikingly, presumptive granule cells of the dentate gyrus are generated but fail to mature, lack normal sodium currents, and show little dendritic arborization. Long-term hippocampal slice cultures demonstrate secondary alterations of entorhinal and commissural/associational projections. The primary developmental arrest appears to be restricted to granule cells in which an autoregulatory system involving all three neuronal bHLH genes has failed.
Population Vector Coding by the Giant Interneurons of the Cockroach
Authors: Levi Rafael , Camhi Jeffrey M.
Published: April 2018

We tested two alternative models of integration among the cockroach giant interneurons (GIs) for determining the directions of wind-evoked escape turns. One model, called steering wheel, pits contralateral GIs against one another; the other, called population vector model, involves a vector computation among the GIs. In testing each model theoretically, the population vector was found to account far better for the actual behavior. Both models could account for the results of previous behavioral–physiological experiments in which spikes had been added to the right GI3 together with wind stimuli from the right side. The two models revealed a critical behavioral–physiological experimental test that we then performed; namely, when delivering wind from the right side, adding spikes experimentally to the right GI2 should increase turn size according to the steering wheel model but should decrease turn size according to the population vector model. The latter result was obtained. The population vector, but not the steering wheel, model also could account for previous behavioral–physiological experiments in which spikes were added experimentally to a GI contralateral to the wind stimuli. The results support the population vector model as accounting for direction determination among the cockroach GIs.
A Voltage-Independent Calcium Current Inhibitory Pathway Activated by Muscarinic Agonists in Rat Sympathetic Neurons Requires Both Gαq/11and Gβγ
Authors: Kammermeier Paul J. , Ruiz-Velasco Victor , Ikeda Stephen R.
Published: April 2018

Calcium current modulation by the muscarinic cholinergic agonist oxotremorine methiodide (oxo-M) was examined in sympathetic neurons from the superior cervical ganglion of the rat. Oxo-M strongly inhibited calcium currents via voltage-dependent (VD) and voltage-independent (VI) pathways. These pathways could be separated with the use of the specific M1acetylcholine receptor antagonist M1-toxin and with pertussis toxin (PTX) treatment. Expression by nuclear cDNA injection of the regulator of G-protein signaling (RGS2) or a phospholipase Cβ1 C-terminal construct (PLCβ-ct) selectively reduced VI oxo-M modulation in PTX-treated and untreated cells. Expression of the Gβγ buffers transducin (Gαtr) and a G-protein-coupled-receptor kinase (GRK3) construct (MAS-GRK3) eliminated oxo-M modulation. Activation of the heterologously expressed neurokinin type 1 receptor, a Gαq/11-coupled receptor, resulted in VI calcium current modulation. This modulation was eliminated with coexpression of Gαtror MAS-GRK3. Cells expressing Gβ1γ2were tonically inhibited via the VD pathway. Application of oxo-M to these cells produced VI modulation and reduced the amount of current inhibited via the VD pathway. Together, these results confirm the requirement for Gβγ in VD modulation and implicate Gαq-GTP and Gβγ as components in the potentially novel VI pathway.
Reduced Voltage Sensitivity of Activation of P/Q-Type Ca2+Channels is Associated with the Ataxic Mouse MutationRolling Nagoya(tgrol)
Authors: Mori Yasuo , Wakamori Minoru , Oda Sen-ichi , Fletcher Colin F. , Sekiguchi Naomi , Mori Emiko , Copeland Neal G. , Jenkins Nancy A. , Matsushita Kaori , Matsuyama Zenjiro , Imoto Keiji
Published: April 2018

Recent genetic analyses have revealed an important association of the gene encoding the P/Q-type voltage-dependent Ca2+channel α1Asubunit with hereditary neurological disorders. We have identified the ataxic mouse mutation,rolling Nagoya(tgrol), in the α1Agene that leads to a charge-neutralizing arginine-to-glycine substitution at position 1262 in the voltage sensor-forming segment S4 in repeat III. Ca2+channel currents in acutely dissociated Purkinje cells, where P-type is the dominant type, showed a marked decrease in slope and a depolarizing shift by 8 mV of the conductance–voltage curve and reduction in current density intgrolmouse cerebella, compared with those in wild-type. Compatible functional change was induced by thetgrolmutation in the recombinant α1Achannel, indicating that a defect in voltage sensor of P/Q-type Ca2+channels is the direct consequence of thetgrolmutation. Furthermore, somatic whole-cell recording of mutant Purkinje cells displayed only abortive Na+burst activity and hardly exhibited Ca2+spike activity in cerebellar slices. Thus, intgrolmice, reduced voltage sensitivity, which may derive from a gating charge defect, and diminished activity of the P-type α1ACa2+channel significantly impair integrative properties of Purkinje neurons, presumably resulting in locomotor deficits.
Cell Surface Trk Receptors Mediate NGF-Induced Survival While Internalized Receptors Regulate NGF-Induced Differentiation
Authors: Zhang Yan-zhen , Moheban Daniel B. , Conway Bevil R. , Bhattacharyya Anita , Segal Rosalind A.
Published: April 2018

Internalization and transport of a ligand-receptor complex are required to initiate cell body responses to target-derived neurotrophin. However, it is not known whether internalized receptors and cell surface receptors initiate the same signaling pathways and biological responses. Here we use a temperature-sensitive mutant of dynamin (G273D) to control the subcellular localization of activated NGF receptors (Trks). We show that dynamin function is required for ligand-dependent endocytosis of Trk receptors. In PC12 cells, nerve growth factor (NGF) stimulation promotes both survival and neuronal differentiation. These distinct biological responses to NGF are controlled by receptors signaling from different locations within the cell. Neuronal differentiation is promoted by catalytically active Trks within endosomes in the cell interior. In contrast, survival responses are initiated by activated receptors at the cell surface where they orchestrate prolonged activation of the kinase Akt. Thus, interactions between Trk receptor tyrosine kinases and intracellular signaling molecules are dictated both by phosphotyrosine motifs within the receptors and by the intracellular location of phosphorylated receptors.
Ibuprofen Suppresses Plaque Pathology and Inflammation in a Mouse Model for Alzheimer's Disease
Authors: Lim G. P. , Yang F. , Chu T. , Chen P. , Beech W. , Teter B. , Tran T. , Ubeda O. , Ashe K. Hsiao , Frautschy S. A. , Cole G. M.
Published: April 2018

The brain in Alzheimer's disease (AD) shows a chronic inflammatory response characterized by activated glial cells and increased expression of cytokines and complement factors surrounding amyloid deposits. Several epidemiological studies have demonstrated a reduced risk for AD in patients using nonsteroidal anti-inflammatory drugs (NSAIDs), prompting further inquiries about how NSAIDs might influence the development of AD pathology and inflammation in the CNS. We tested the impact of chronic orally administered ibuprofen, the most commonly used NSAID, in a transgenic model of AD displaying widespread microglial activation, age-related amyloid deposits, and dystrophic neurites. These mice were created by overexpressing a variant of the amyloid precursor protein found in familial AD. Transgene-positive (Tg+) and negative (Tg−) mice began receiving chow containing 375 ppm ibuprofen at 10 months of age, when amyloid plaques first appear, and were fed continuously for 6 months. This treatment produced significant reductions in final interleukin-1β and glial fibrillary acidic protein levels, as well as a significant diminution in the ultimate number and total area of β-amyloid deposits. Reductions in amyloid deposition were supported by ELISA measurements showing significantly decreased SDS-insoluble Aβ. Ibuprofen also decreased the numbers of ubiquitin-labeled dystrophic neurites and the percentage area per plaque of anti-phosphotyrosine-labeled microglia. Thus, the anti-inflammatory drug ibuprofen, which has been associated with reduced AD risk in human epidemiological studies, can significantly delay some forms of AD pathology, including amyloid deposition, when administered early in the disease course of a transgenic mouse model of AD.
Delayed Mitochondrial Dysfunction in Excitotoxic Neuron Death: CytochromecRelease and a Secondary Increase in Superoxide Production
Authors: Luetjens C. Marc , Bui Nguyen Truc , Sengpiel Bernd , Münstermann Gudrun , Poppe Monika , Krohn Aaron J. , Bauerbach Elke , Krieglstein Josef , Prehn Jochen H. M.
Published: April 2018

An increased production of superoxide has been shown to mediate glutamate-induced neuron death. We monitored intracellular superoxide production of hippocampal neurons during and after exposure to the glutamate receptor agonist NMDA (300 μm). During a 30 min NMDA exposure, intracellular superoxide production increased significantly and remained elevated for several hours after wash-out of NMDA. After a 5 min exposure, superoxide production remained elevated for 10 min, but then rapidly returned to baseline. Mitochondrial membrane potential also recovered after wash-out of NMDA. However, recovery of mitochondria was transient and followed by delayed mitochondrial depolarization, loss of cytochromec, and a secondary rise in superoxide production 4–8 hr after NMDA exposure. Treatment with a superoxide dismutase mimetic before the secondary rise conferred the same protection against cell death as a treatment before the first. The secondary rise could be inhibited by the complex I inhibitor rotenone (in combination with oligomycin) and mimicked by the complex III inhibitor antimycin A. To investigate the relationship between cytochromecrelease and superoxide production, human D283 medulloblastoma cells deficient in mitochondrial respiration (ρ−cells) were exposed to the apoptosis-inducing agent staurosporine. Treatment with staurosporine induced mitochondrial release of cytochromec, caspase activation, and cell death in control and ρ−cells. However, a delayed increase in superoxide production was only observed in control cells. Our data suggest that the delayed superoxide production in excitotoxicity and apoptosis occurs secondary to a defect in mitochondrial electron transport and that mitochondrial cytochromecrelease occurs upstream of this defect.
Remote Episodic Memory Deficits in Patients with Unilateral Temporal Lobe Epilepsy and Excisions
Authors: Viskontas Indre V. , McAndrews Mary Pat , Moscovitch Morris
Published: April 2018

The nature of remote memory impairment in patients with medial temporal lobe damage is the subject of some debate. While some investigators have found that retrograde amnesia in such patients is temporally graded, with relative sparing of remote memories (Squire and Alvarez, 1995), others contend that impairment is of very long duration and that remote memories are not necessarily spared (Sanders and Warrington, 1971; Nadel and Moscovitch, 1997). In this study, remote memory was assessed in 25 patients with unilateral temporal lobe epilepsy and 22 non-neurologically impaired controls using the Autobiographical Memory Interview (Kopelman et al., 1989). Results indicate that patients have impaired personal episodic memory but intact personal semantic memory. The impairment extends even to the most remote time periods in early childhood, long before seizure onset in many patients. As well, patients awaiting temporal lobectomy for control of seizures perform as poorly as those who have already undergone resective surgery. These results support the hypothesis that temporal lobe damage or dysfunction, caused by recurrent seizures or surgical excision, results in extensive retrograde amnesia for personal episodic memories. Interestingly, patients with radiological evidence of hippocampal sclerosis were not significantly more impaired than those without obvious sclerosis. These results indicate that even minimal damage to medial temporal lobes results in significant impairment to autobiographical episodic memory. These findings are more compatible with a memory loss or retrieval deficit rather than a consolidation account of remote memory impairment.
Cav1.4α1 Subunits Can Form Slowly Inactivating Dihydropyridine-Sensitive L-Type Ca2+Channels Lacking Ca2+-Dependent Inactivation
Authors: Koschak Alexandra , Reimer Daniel , Walter Doris , Hoda Jean-Charles , Heinzle Thomas , Grabner Manfred , Striessnig Jörg
Published: April 2018

The neuronal L-type calcium channels (LTCCs) Cav1.2α1 and Cav1.3α1 are functionally distinct. Cav1.3α1 activates at lower voltages and inactivates more slowly than Cav1.2α1, making it suitable to support sustained L-type Ca2+inward currents (ICa,L) and serve in pacemaker functions. We compared the biophysical and pharmacological properties of human retinal Cav1.4α1 using the whole-cell patch-clamp technique after heterologous expression in tsA-201 cells with other L-type α1 subunits. Cav1.4α1-mediated inward Ba2+currents (IBa) required the coexpression of α2δ1 and β3 or β2a subunits and were detected in a lower proportion of transfected cells than Cav1.3α1.IBaactivated at more negative voltages (5% activation threshold; -39mV; 15 mmBa2+) than Cav1.2α1 and slightly more positive than Cav1.3α1. Voltage-dependent inactivation ofIBawas slower than for Cav1.2α1 and Cav1.3α1(∼50% inactivation after 5 sec; α2δ1 + β3 coexpression). Inactivation was not increased with Ca2+as the charge carrier, indicating the absence of Ca2+-dependent inactivation. Cav1.4α1 exhibited voltage-dependent, G-protein-independent facilitation by strong depolarizing pulses. The dihydropyridine (DHP)-antagonist isradipine blocked Cav1.4α1 with ∼15-fold lower sensitivity than Cav1.2α1 and in a voltage-dependent manner. Strong stimulation by the DHP BayK 8644 was found despite the substitution of an otherwise L-type channel-specific tyrosine residue in position 1414 (repeat IVS6) by a phenylalanine. Cav1.4α1 + α2δ1 + β channel complexes can form LTCCs with intermediate DHP antagonist sensitivity lacking Ca2+-dependent inactivation. Their biophysical properties should enable them to contribute to sustainedICa,Lat negative potentials, such as required for tonic neurotransmitter release in sensory cells and plateau potentials in spiking neurons.
THIN FILM-BASED SENSOR FOR MOTOR VEHICLE EXHAUST GAS, NH3, AND CO DETECTION
Authors: Sujarwata S. , Marwoto P. , Handayani L.
Published: April 2018

A copper phthalocyanine (CuPc) thinfilm based gas sensorwith FET structure and channel length 100?mhas been prepared by VE method and lithography technique to detect NH3, motor cycle exhaust gases andCO. CuPc material layer was deposited on SiO2by the vacuum evaporator (VE) method at room temperature and pressureof 8 x10-4 Pa. The stages of manufacturing gas sensor were Si/SiO2 substrate blenching with ethanol in an ultrasonic cleaner, source, and drain electrodes deposition on the substrate by using a vacuum evaporator, thin film deposition between the source/drain and gate deposition. The sensor response times to NH3, motorcycle exhaust gases and CO were 75 s, 135 s, and 150, respectively. The recovery times were 90 s, 150 s and 225, respectively. It is concluded that the CuPc thin film-based gas sensor with FET structure is the best sensor to detect the NH3 gas.Sensor gas berbasis film tipis copper phthalocyanine (CuPc) berstruktur FET dengan panjang channel 100 ?m telah dibuatdengan metode VE dan teknik lithography untuk mendeteksi NH3 gas buang kendaraan bermotor dan CO. Lapisan bahan CuPc dideposisikan pada permukaan silikon dioksida (SiO2) dengan metode vacuum evaporator (VE) pada temperatur ruang dengan tekanan 8 x10-4 Pa. Tahapan pembuatan sensor gas adalah pencucian substrat Si/SiO2 dengan etanol dalam ultrasonic cleaner, deposisi elektroda source dan drain di atas substrat dengan metode vacuum evaporator, deposisi film tipis diantara source/drain dan deposisi gate. Waktu tanggap sensor terhadap NH3, gas buang kendaraan bermotor dan CO berturut-turut adalah 75 s, 135 s,dan 150 s. Waktu pemulihan berturut-turut adalah 90 s, 150 s,dan 225 s. Disimpulkan bahwa sensor gas berstruktur FET berbasis film tipis CuPc merupakan sensor paling baik untuk mendeteksi adanya gas NH3.
SIKLUS PRAPEMBELAJARAN MODEL PENILAIAN FORMATIF WEB-BASED PADA PEMBELAJARAN FISIKA MATERI SUHU DAN KALOR UNTUK SISWA SMK KELAS X
Authors: Ediyanto E.
Published: April 2018

Model penilaian formatif Web-based dibagi menjadi tiga siklus yaitu siklus prapembelajaran, siklus pembelajaran dan siklus pascapembelajaran. Penelitian kali ini mengembangkan siklus prapembelajaran model penilaian web-based pada mata pelajaran fisika materi suhu dan kalor untuk siswa SMK kelas X. Metode penelitian yang digunakan dalam penelitian ini adalah penelitian dan pengembangan. Langkah-langkah yang digunakan untuk pengembangan siklus prapembelajaran model penilaian formatif web-based yaitu 1) mengumpulkan informasi, 2) melakukan perencanaan, 3) mengembangkan bentuk produk awal, 4) melakukan uji permulaan, 5) revisi, dan 6) Uji coba. Berdasarkan hasil uji coba, ditemukan bahwa siklus prapembelajaran model penilaian formatif web-based dapat membantu guru dan siswa untuk mendapatkan umpan balik yang cepat. Umpan balik yang cepat dapat membantu siswa untuk mendapatkan pemahaman konsep dengan cepat dan dapat membantu guru untuk menemukan masalah siswa sehingga dapat dipecahkan dengan cepat.Web-based Formative Assessment Model is divided into three cycles: pre-teaching, whilst teaching, post-teaching. This research develops Pre-teaching Cycle of Formative Web-Based Assessment Model on physics material teaching: Temperature and Heat for X Grader of Vocational High School Students. The method used in this research is a Research and Development (R & D). The steps used for the development of pre-learning cycle of web-based formative assessment models: 1) collecting information, 2) conducting planning, 3) developing pre-product form, 4) conducting pre-test, 5) revision, 6) trial test. Based on the trial test, the findings show that pre-teaching cycle of formative web-based assessment model is able to assist teachers and students to get fast feedback. Fast feedback can helps students to gain fast conceptual comprehension and help teachers to find out the students problems so it enables to solve faster.
Thickness Dependence of Magnetic Switching Dynamics of Barium-Ferrite as A High-Density Perpendicular Magnetic Storage Media
Authors: Aji P. P. , Rondonuwu F. S. , Wibowo N. A.
Published: April 2018

Micromagnetic study of material thickness dependence of Barium-ferrite nano-dot magnetization dynamics has been performed. The used materials characteristics in this research represent the properties of Barium-ferrite. Barium-ferrite was modeled as a nano-dot with a surface area of 50 50 nm2 and its thickness varies from 5 nm to 100 nm. This nano-dot was simulated using micromagnetic simulator software by solving Landau-Lifshitz-Gilbert equation. According to this study, obtained that the Barium-ferrite nano-dot has excellent thermal stability. Magnetization rate of this nano-dot decreases exponentially with the increase of thickness. The fastest magnetization rate observed in 5 nm of nano-dot thickness, meanwhile 45 nm for the slowest rate. Magnetization reversal mode of this Barium-ferrite nano-dot is dominated by domain wall nucleation and propagation. During the propagation of the domain wall, the exchange interaction becomes the main aspect compared to the other contributed energies.
Improvement of Graph Interpretation Ability Using Hypertext-Assisted Kinematic Learning and Formal Thinking Ability
Authors: Manurung S. R. , Mihardi S. , Rustaman N. Y. , Siregar N.
Published: April 2018

The effectiveness of hypertext media in improving graph interpretation ability is investigated in this paper. In addition, joint ability of the formal thinking to improve the graph ability of prospective students is considered. The research design used is the one-group pretest-posttest experimental design is carried out in the research by taking 36 students on from Physics Education Program in one institute for teacher education in Medan. The test consists of graph interpretation ability test in the topic of kinematics and Test of Logical Thinking (TOLT or formal thinking) before learning and graph interpretation ability test after learning. The data are then analysed by using SPSS based two ways Analisys of Variance (ANOVA) method. The results show that the ability to interpretate graph is significantly improved by using hypertext media assisted kinematic learning.
Activation of lysosomal cathepsins in pregnant bovine leukocytes
Authors: Talukder Md Abdus Shabur , Balboula Ahmed Zaky , Shirozu Takahiro , Kim Sung Woo , Kunii Hiroki , Suzuki Toshiyuki , Ito Tsukino , Kimura Koji , Takahashi Masashi
Published: April 2018

In ruminants, interferon-tau (IFNT)-mediated expression of interferon-stimulated genes in peripheral blood leukocytes (PBLs) can indicate pregnancy. Recently, type 1 IFN-mediated activation of lysosomes and lysosomal cathepsins (CTSs) was observed in immune cells. This study investigated the status of lysosomal CTSs and lysosomes in PBLs collected from pregnant (P) and non-pregnant (NP) dairy cows, and conductedin vitroIFNT stimulation of NP blood leukocytes. Blood samples were collected 0, 7, 14 and 18 days post-artificial insemination, and the peripheral blood mononuclear cells (PBMCs) and polymorphonuclear granulocytes (PMNs) separated. The fluorescent activity of CTSB and CTSK in PMNs significantly increased with the progress of pregnancy, especially on day 18.In vitrosupplementation of IFNT significantly increased the activities of CTSB and CTSK in NP PBMCs and PMNs.CTSBexpression was significantly higher in PBMCs and PMNs collected from P day-18 cows than from NP cows, whereas there was no difference inCTSKexpression. IFNT increasedCTSBexpression but did not affectCTSKexpression. Immunodetection showed an increase of CTSB in P day-18 PBMCs and PMNs.In vitrostimulation of IFNT increased CTSB in NP PBMCs and PMNs. Lysosomal acidification showed a significant increase in P day-18 PBMCs and PMNs. IFNT also stimulated lysosomal acidification. Expressions of lysosome-associated membrane protein (LAMP) 1 and LAMP2 were significantly higher in P day-18 PBMCs and PMNs. The results suggest that pregnancy-specific activation of lysosomal functions by CTS activation in blood leukocytes is highly associated with IFNT during maternal and fetal recognition of pregnancy.
Adaptaciones 'stopmotion' de 'James and the Giant Peach' y 'Fantastic Mr. Fox' de Roald Dahl
Authors: G-Pedreira Rocío , Cortizas Varela Olalla
Published: April 2018

El objetivo de este breve artículo es analizar el uso de la técnica cinematográfica del stopmotion en dos películas de animación basadas en James and the Giant Peach (1961) y Fantastic Mr. Fox (1979), de la autoría de Roald Dahl (United Kingdom, 1916-1990), profundizando en el proceso de adaptación al formato audiovisual teniendo en cuenta la retórica del relato fantástico. La primera de ellas es una película de Walt Disney Pictures, producida por Tim Burton y Denise di Nove, dirigida por Henry Selick y estrenada en 1996; la segunda de ellas fue producida por Indian Paintbrush y Regency Enterprises, dirigida por Wes Anderson y estrenada en 2009. Por tanto, se hará un pequeño marco teórico sobre la Literatura Infantil y Juvenil fantástica, el cine de animación y la influencia que la semiótica de ambos lenguajes tiene en la adaptación resultante de su combinación.