bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitric Oxide Production in Rat Thalamus Changes with Behavioral State, Local Depolarization, and Brainstem Stimulation
Authors: Williams Julie A. , Vincent Steven R. , Reiner Peter B.
Published: April 2018

Since its discovery as a putative neurotransmitter in the CNS, several functional roles have been suggested for nitric oxide (NO). However, few studies have investigated the role of NO in natural physiology. Because NO synthase (NOS) has been localized in regions believed to be important for attention and arousal, we hypothesized that NO production would be state-dependent. To test this hypothesis, we usedin vivomicrodialysis, coupled with the hemoglobin-trapping technique, to monitor extracellular NO concentrations in rat thalamus during wake, slow-wave sleep (SWS), and rapid eye movement (REM) sleep. The thalamus is known to receive a massive innervation from the NOS/cholinergic neurons in the mesopontine brainstem, which have been suggested to play a key role in EEG desynchronized states. To test whether thalamic NO output was sensitive to neuronal-dependent changes in the mesopontine brainstem, we measured thalamic NO concentration in response to electrical stimulation in the laterodorsal tegmentum (LDT) of anesthetized rats. Finally, the calcium dependence of NO release was tested by local depolarization with a high potassium dialysate or by addition of a calcium chelator. The results showed that (1) extracellular NO concentrations in the thalamus were high during wake and REM sleep and significantly lower during SWS, (2) thalamic NO release increased in response to LDT stimulation in both a site-specific and tetrodotoxin (TTX)-dependent manner, and (3) NO production was calcium-dependent. These data suggest that thalamic NO production may play a role in arousal.
Synthesis of β-Tubulin, Actin, and Other Proteins in Axons of Sympathetic Neurons in Compartmented Cultures
Authors: Eng Hubert , Lund Karen , Campenot Robert B.
Published: April 2018

The proteins needed for growth and maintenance of the axon are generally believed to be synthesized in the cell bodies and delivered to the axons by anterograde transport. However, recent reports suggest that some proteins can also be synthesized within axons. We used [35S]methionine metabolic labeling to investigate axonal protein synthesis in compartmented cultures of sympathetic neurons from newborn rats. Incubation of distal axons for 4 hr with [35S]methionine resulted in a highly specific pattern of labeled axonal proteins on SDS-PAGE, with 4 prominent bands in the 43–55 kDa range. The labeled proteins in axons were not synthesized in the cell bodies, because they were also produced by axons after the cell bodies had been removed. Two of the proteins were identified by immunoprecipitation as actin and β-tubulin. Axons synthesized <1% of the actin and tubulin synthesized in the cell bodies and transported into the axons, and 75–85% inhibition of axonal protein synthesis by cycloheximide and puromycin failed to inhibit axonal elongation. Nonetheless, the specific production by axons of the major proteins of the axonal cytoskeleton suggests that axonal protein synthesis arises from specific mechanisms and likely has biological significance. One hypothetical scenario involves neurons with long axonsin vivoin which losses from turnover during axonal transport may limit the availability of cell body synthesized proteins to the distal axons. In this case, a significant fraction of axonal proteins might be supplied by axonal synthesis, which could, therefore, play important roles in axonal maintenance, regeneration, and sprouting.
Peripheral Synapses at Identified Mechanosensory Neurons in Spiders: Three-Dimensional Reconstruction and GABA Immunocytochemistry
Authors: Fabian-Fine Ruth , Höger Ulli , Seyfarth Ernst-August , Meinertzhagen Ian A.
Published: April 2018

The mechanosensory organs of arachnids receive diverse peripheral inputs. Little is known about the origin, distribution, and function of these chemical synapses, which we examined in lyriform slit sense organ VS-3 of the spiderCupiennius salei. The cuticular slits of this organ are each associated with two large bipolar mechanosensory neurons with different adaptation rates. With intracellular recording, we have now been able to correlate directly the staining intensity of a neuron for acetylcholinesterase with its adaptation rate, thus allowing us simply to stain a neuron to identify its functional type. All rapidly adapting neurons stain more heavily than slowly adapting neurons. Immunostaining of whole-mount preparations reveals GABA-like immunoreactive fibers forming numerous varicosities at the surface of all sensory neurons in VS-3; peripheral GABA-like immunoreactive somata are lacking. Sectioning the leg nerve procures rapid degeneration of most fiber profiles, confirming that the fibers are efferent. Punctate synapsin-like immunoreactivity colocalizes to these varicosities, although some synapsin-like immunoreactive puncta are GABA-immunonegative. Fibers with similar immunoreactivities are also associated with trichobothria, tactile hairs, internal joint receptors, i.e. other types of spider mechanosensory organs. In organ VS-3, immunoreactivity is most dense across the initial axon segment. The exact distribution of peripheral synapses was reconstructed from a 10-μm-long electron micrograph series of the dendritic, somatic, and initial axon regions of acetylcholinesterase-stained VS-3 neurons. These reveal a pattern similar to that of the synapsin-like immunoreactivity. Two different types of synapse were distinguished on the basis of their presynaptic vesicle populations. Many peripheral synapses thus appear to derive from efferent GABA-like immunoreactive fibers and probably provide centrifugal inhibitory control of primary mechanosensory activities.
Cellular Traces of Behavioral Classical Conditioning Can Be Recorded at Several Specific Sites in a Simple Nervous System
Authors: Staras Kevin , Kemenes György , Benjamin Paul R.
Published: April 2018

We used a behavioral learning paradigm followed by electrophysiological analysis to find sites in theLymnaeafeeding network in which electrical changes could be recorded after appetitive conditioning. Specifically, we analyzed conditioning-induced changes in cellular responses in the mechanosensory conditioned stimulus (CS) pathway, in the central pattern generator (CPG) network, and in feeding motoneurons. During training, experimental animals received 15 pairings of lip touch (the CS) with sucrose (the unconditioned stimulus, US). Control animals received 15 random CS and US presentations. Electrophysiological tests on semi-intact preparations made from conditioned animals demonstrated a network correlate of the overall feeding conditioned response, a touch-evoked CPG-driven fictive feeding rhythm. At the motoneuronal level, we found significant conditioning-induced increases in the amplitude of an early touch-evoked EPSP and spike activity, recorded from the B3 feeding motoneuron. Increases in EPSP amplitude and motoneuronal spike activity could occur independently of conditioned fictive feeding. These changes in response recorded at the level of CPG interneurons, and motoneurons were preceded by changes recorded in the CS pathway. This was demonstrated by recording a conditioning-induced increase in the number of touch-evoked spikes in the cerebrobuccal connective, which forms part of the CS pathway. The finding that electrophysiological changes after conditioning can be recorded at multiple sites in this simple system provided an important intermediate level of analysis between whole animal behavior and cellular studies on the synaptic sites of plasticity.
Pain Pathways Involved in Fear Conditioning Measured with Fear-Potentiated Startle: Lesion Studies
Authors: Shi Changjun , Davis Michael
Published: April 2018

It is well established that the basolateral amygdala is critically involved in the association between an unconditioned stimulus (US), such as a foot shock, and a conditioned stimulus (CS), such as a light, during classic fear conditioning. However, little is known about how the US (pain) inputs are relayed to the basolateral amygdala. The present studies were designed to define potential US pathways to the amygdala using lesion methods. Electrolytic lesions before or after training were placed in caudal granular/dysgranular insular cortex (IC) alone or in conjunction with the posterior intralaminar nuclei of the thalamus (PoT/PIL), and the effects on fear conditioning were examined. Pretraining lesions of both IC and PoT/PIL, but not lesions of IC alone, blocked the acquisition of fear-potentiated startle. However, post-training combined lesions of IC and PoT/PIL did not prevent expression of conditioned fear. Given that previous studies have shown that lesions of PoT/PIL alone had no effect on acquisition of conditioned fear, these results suggest that two parallel cortical (insula–amygdala) and subcortical (PoT/PIL–amygdala) pathways are involved in relaying shock information to the basolateral amygdala during fear conditioning.
Facilitation of Sexual Behavior and Enhanced Dopamine Efflux in the Nucleus Accumbens of Male Rats afterd-Amphetamine-Induced Behavioral Sensitization
Authors: Fiorino Dennis F. , Phillips Anthony G.
Published: April 2018

Behavioral sensitization caused by repeated and intermittent administration of psychostimulants, such as cocaine andd-amphetamine, is accompanied by enhanced function in limbic-motor circuitry that is involved in the generation of motivated behavior. The present microdialysis study investigated the effect ofd-amphetamine-induced sensitization on dopamine (DA) efflux in the nucleus accumbens (NAC) of male rats during sexual behavior. Male rats were given one injection ofd-amphetamine (1.5 mg/kg, i.p.) or saline every other day for a total of 10 injections. Three weeks after discontinuation of drug treatment, rats were tested for sexual behavior during a test in which microdialysis was performed. There was an augmented efflux of DA in the NAC ofd-amphetamine-sensitized rats compared with nonsensitized control rats when a receptive female was present behind a screen (35 vs 17%). Sensitized rats exhibited facilitated sexual behavior when the screen was removed, as indicated by a significantly shorter latency to mount and an overall increase in the amount of copulatory behavior. Although there was a significant increase in NAC DA concentrations from baseline in both sensitized and nonsensitized rats during copulation, there was a greater increase in DA efflux in the NAC of sensitized rats during the first 10 min copulatory sample (60 vs 37%). These results demonstrate that behavioral sensitization caused by repeated psychostimulant administration can “cross-sensitize” to a natural behavior, such as sex, and that increased NAC DA release may contribute to the facilitation of appetitive and consummatory aspects of this behavior.
2,3-Dihydroxy-6-Nitro-7-Sulfamoyl-Benzo(f)Quinoxaline Reduces Glial Loss and Acute White Matter Pathology after Experimental Spinal Cord Contusion
Authors: Rosenberg Lisa J. , Teng Yang D. , Wrathall Jean R.
Published: April 2018

Focal microinjection of 2,3-dihyro-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX), an antagonist of the AMPA/kainate subclass of glutamate receptors, reduces neurological deficits and tissue loss after spinal cord injury. Dose-dependent sparing of white matter is seen at 1 month after injury that is correlated to the dose-related reduction in chronic functional deficits. To determine whether NBQX exerts an acute effect on white matter pathology, female, adult Spague Dawley rats were subjected to a standardized weight drop contusion at T-8 (10 gm × 2.5 cm) and NBQX (15 nmol) or vehicle (VEH) solution focally injected into the injury site 15 min later. At 4 and 24 hr, tissue from the injury epicenter was processed for light and electron microscopy, and the histopathology of ventromedial white matter was compared. The axonal injury index, a quantitative representation of axoplasmic and myelinic pathologies, was significantly lower in the NBQX group at 4 hr (2.7 ± 0.24, mean ± SE) and 24 hr (1.4 ± 0.19) than in VEH controls (3.8 ± 0.33 and 2.1 ± 0.20, respectively). Counts of glial cell nuclei indicated a loss of at least 60% at 4 and 24 hr after injury in the VEH group compared with uninjured controls. NBQX treatment reduced this glial loss by half. Immunohistochemistry revealed that the spared glia were primarily oligodendrocytes. Thus, the chronic effects of NBQX in reducing white matter loss after spinal cord injury appear to be attributable to the reduction of acute pathology and may be mediated through the protection of glia, particularly oligodendrocytes.
Neuropharmacological Dissection of Placebo Analgesia: Expectation-Activated Opioid Systems versus Conditioning-Activated Specific Subsystems
Authors: Amanzio Martina , Benedetti Fabrizio
Published: April 2018

We investigated the mechanisms underlying the activation of endogenous opioids in placebo analgesia by using the model of human experimental ischemic arm pain. Different types of placebo analgesic responses were evoked by means of cognitive expectation cues, drug conditioning, or a combination of both. Drug conditioning was performed by means of either the opioid agonist morphine hydrochloride or the nonopioid ketorolac tromethamine. Expectation cues produced placebo responses that were completely blocked by the opioid antagonist naloxone. Expectation cues together with morphine conditioning produced placebo responses that were completely antagonized by naloxone. Morphine conditioning alone (without expectation cues) induced a naloxone-reversible placebo effect. By contrast, ketorolac conditioning together with expectation cues elicited a placebo effect that was blocked by naloxone only partially. Ketorolac conditioning alone produced placebo responses that were naloxone-insensitive. Therefore, we evoked different types of placebo responses that were either naloxone-reversible or partially naloxone-reversible or, otherwise, naloxone-insensitive, depending on the procedure used to evoke the placebo response. These findings show that cognitive factors and conditioning are balanced in different ways in placebo analgesia, and this balance is crucial for the activation of opioid or nonopioid systems. Expectation triggers endogenous opioids, whereas conditioning activates specific subsystems. In fact, if conditioning is performed with opioids, placebo analgesia is mediated via opioid receptors, if conditioning is performed with nonopioid drugs, other nonopioid mechanisms result to be involved.
Functionally Dissociating Aspects of Event Memory: the Effects of Combined Perirhinal and Postrhinal Cortex Lesions on Object and Place Memory in the Rat
Authors: Bussey Timothy J. , Muir Janice L. , Aggleton John P.
Published: April 2018

Reciprocal interactions between the hippocampus and the perirhinal and parahippocampal cortices form core components of a proposed temporal lobe memory system. For this reason, the involvement of the hippocampus in event memory is thought to depend on its connections with these cortical areas. Contrary to these predictions, we found that NMDA-induced lesions of the putative rat homologs of these cortical areas (perirhinal plus postrhinal cortices) did not impair performance on two allocentric spatial tasks highly sensitive to hippocampal dysfunction. Remarkably, for one of the tasks there was evidence of a facilitation of performance. The same cortical lesions did, however, disrupt spontaneous object recognition and object discrimination reversal learning but spared initial acquisition of the discrimination. This pattern of results reveals important dissociations between different aspects of memory within the temporal lobe. Furthermore, it shows that the perirhinal–postrhinal cortex is not a necessary route for spatial information reaching the hippocampus and that object familiarity–novelty detection depends on different neural substrates than do other aspects of event memory.
Developmentally Regulated NMDA Receptor-Dependent Dephosphorylation of cAMP Response Element-Binding Protein (CREB) in Hippocampal Neurons
Authors: Sala Carlo , Rudolph-Correia Sheila , Sheng Morgan
Published: April 2018

Developmental changes in the signaling properties of NMDA receptors have been proposed to underlie the loss of plasticity that accompanies brain maturation. Calcium influx through postsynaptic NMDA receptors can stimulate neuronal gene expression via signaling pathways such as the Ras-MAP kinase (MAPK) pathway and the transcription factor cAMP response element-binding protein (CREB). We analyzed MAPK (Erk1/2) and CREB activation in response to NMDA receptor stimulation during the development of hippocampal neurons in culture. At all stages of development NMDA stimulation induced a rapid phosphorylation of CREB on Ser-133 (phospho-CREB). However, the time course of decline in phospho-CREB changed dramatically with neuronal maturation. At 7 din vitro(7 DIV) phospho-CREB remained elevated 2 hr after strong NMDA stimulation, whereas at 14 DIV phospho-CREB rose only transiently and fell back to below basal levels within 30 min. Moreover, at 14 DIV, but not at 7 DIV, NMDA receptor stimulation induced a dephosphorylation of CREB that previously had been phosphorylated by KCl depolarization or forskolin, suggesting an NMDA receptor-dependent activation of a CREB phosphatase. There was no developmental change in the time course of phospho-CREB induction that followed KCl depolarization or PKA activation, nor was there a developmental change in the time course of phospho-Erk1/2 induced by NMDA receptor activation. We suggest that, during neuronal maturation, NMDA receptor activation becomes linked specifically to protein phosphatases that act on Ser-133 of CREB. Such a developmentally regulated switch in the mode of NMDA receptor coupling to intracellular signaling pathways may contribute to the changes in neural plasticity observed during brain development.
Synapsin III: Developmental Expression, Subcellular Localization, and Role in Axon Formation
Authors: Ferreira Adriana , Kao Hung-Teh , Feng Jian , Rapoport Mark , Greengard Paul
Published: April 2018

We have investigated the developmental expression and subcellular localization of synapsin III, the newest member of the synapsin family, in cultured mouse hippocampal neurons. Our results indicate that synapsin III is expressed early during development, with levels peaking 7 d after plating and declining thereafter. Synapsin III is highly concentrated in growth cones. Using specific antisense oligonucleotides, we have also examined the effect of depleting synapsin III on neurite elongation and synaptogenesis. When synapsin III was suppressed immediately after plating, hippocampal neurons extended minor processes but failed to differentiate one of them as the axon. The suppression of synapsin III after axonal elongation did not affect the time course of synapse formation. The results indicate that synapsin III has a developmental time course, a subcellular localization, and a developmental function very different from those of synapsin I and synapsin II.
Association of β1 Integrin with Focal Adhesion Kinase and Paxillin in Differentiating Schwann Cells
Authors: Chen Li-Mei , Bailey Debora , Fernandez-Valle Cristina
Published: April 2018

Schwann cells (SCs) differentiate into a myelinating cell when simultaneously adhering to an axon destined for myelination and basal lamina. We are interested in defining the signaling pathway activated by basal lamina. Using SC/sensory neuron (N) cocultures, we identified β1 integrin and F-actin as components of a pathway leading to myelin gene expression and myelination (Fernandez-Valle et al., 1994, 1997). Here, we show that focal adhesion kinase (FAK) and paxillin are constitutively expressed by SCs contacting axons in the absence of basal lamina. Tyrosine phosphorylation of FAK and paxillin increases as SCs form basal lamina and differentiate. FAK and paxillin specifically coimmunoprecipitate with β1 integrin in differentiating SC/N cocultures but not SC-only cultures. Paxillin coimmunoprecipitates with FAK and fyn kinase in differentiating SC/N cocultures. A subset of tyrosine-phosphorylated β1 integrin, FAK, and paxillin molecules reside in the insoluble, F-actin-rich fraction of differentiating cocultures. Cytochalasin D, an actin depolymerizing agent, decreases tyrosine phosphorylation of FAK and paxillin and their association with β1 integrin and causes a dose-dependent increase in the abundance of insoluble FAK and paxillin complexes. Collectively, our work indicates that β1 integrin, FAK, paxillin, and fyn kinase form an actin-associated complex in SCs adhering to basal lamina in the presence of axons. This complex may be important for initiating the process of SC differentiation into a myelinating cell.
Distribution, Targeting, and Internalization of the sst4Somatostatin Receptor in Rat Brain
Authors: Schreff Matthias , Schulz Stefan , Händel Manuela , Keilhoff Gerburg , Braun Holger , Pereira Gabriela , Klutzny Marcus , Schmidt Harald , Wolf Gerald , Höllt Volker
Published: April 2018

Somatostatin mediates its diverse physiological effects through a family of five G-protein-coupled receptors (sst1–sst5); however, knowledge about the distribution of individual somatostatin receptor proteins in mammalian brain is incomplete. In the present study, we have examined the regional and subcellular distribution of the somatostatin receptor sst4in the rat CNS by raising anti-peptide antisera to the C-terminal tail of sst4. The specificity of affinity-purified antibodies was demonstrated using immunofluorescent staining of HEK 293 cells stably transfected with an epitope-tagged sst4receptor. In Western blotting, the antiserum reacted specifically with a broad band in rat brain, which migrated at ∼70 kDa before and ∼50 kDa after enzymatic deglycosylation. sst4-Like immunoreactivity was most prominent in many forebrain regions, including the cerebral cortex, hippocampus, striatum, amygdala, and hypothalamus. Analysis at the electron microscopic level revealed that sst4-expressing neurons target this receptor preferentially to their somatodendritic domain. Like the sst2Areceptor, sst4-immunoreactive dendrites were often closely apposed by somatostatin-14-containing fibers and terminals. However, unlike the sst2Areceptor, sst4was not internalized in response to intracerebroventricular administration of somatostatin-14. After percussion trauma of the cortex, neuronal sst4receptors progressively declined at the sites of damage. This decline coincided with an induction of sst4expression in cells with a glial-like morphology. Together, this study provides the first description of the distribution of immunoreactive sst4receptor proteins in rat brain. We show that sst4is strictly somatodendritic and most likely functions in a postsynaptic manner. In addition, the sst4receptor may have a previously unappreciated function during the neuronal degeneration–regeneration process.
Efficacy and Stability of Quantal GABA Release at a Hippocampal Interneuron–Principal Neuron Synapse
Authors: Kraushaar Udo , Jonas Peter
Published: April 2018

We have examined factors that determine the strength and dynamics of GABAergic synapses between interneurons [dentate gyrus basket cells (BCs)] and principal neurons [dentate gyrus granule cells (GCs)] using paired recordings in rat hippocampal slices at 34°C. Unitary IPSCs recorded from BC–GC pairs in high intracellular Cl−concentration showed a fast rise and a biexponential decay, with mean time constants of 2 and 9 msec. The mean quantal conductance change, determined directly at reduced extracellular Ca2+/Mg2+concentration ratios, was 1.7 nS. Quantal release at the BC–GC synapse occurred with short delay and was highly synchronized. Analysis of IPSC peak amplitudes and numbers of failures by multiple probability compound binomial analysis indicated that synaptic transmission at the BC–GC synapse involves three to seven release sites, each of which releases transmitter with high probability (∼0.5 in 2 mmCa2+/1 mmMg2+). Unitary BC–GC IPSCs showed paired-pulse depression (PPD); maximal depression, measured for 10 msec intervals, was 37%, and recovery from depression occurred with a time constant of 2 sec. Paired-pulse depression was mainly presynaptic in origin but appeared to be independent of previous release. Synaptic transmission at the BC–GC synapse showed frequency-dependent depression, with half-maximal decrease at 5 Hz after a series of 1000 presynaptic action potentials. The relative stability of transmission at the BC–GC synapse is consistent with a model in which an activity-dependent gating mechanism reduces release probability and thereby prevents depletion of the releasable pool of synaptic vesicles. Thus several mechanisms converge on the generation of powerful and sustained transmission at interneuron–principal neuron synapses in hippocampal circuits.
The Dopamine/D1 Receptor Mediates the Phosphorylation and Inactivation of the Protein Tyrosine Phosphatase STEP via a PKA-Dependent Pathway
Authors: Paul Surojit , Snyder Gretchen L. , Yokakura Hisayuki , Picciotto Marina R. , Nairn Angus C. , Lombroso Paul J.
Published: April 2018

The striatal-enriched protein tyrosine phosphatase (STEP) family is expressed within dopaminoceptive neurons of the CNS and is particularly enriched within the basal ganglia and related structures. Alternative splicing produces several isoforms that are found in a number of subcellular compartments, including postsynaptic densities of medium spiny neurons. The variants include STEP61, a membrane-associated protein, and STEP46, a cytosolic protein. The C terminals of these two isoforms are identical, whereas the N-terminal domain of STEP61contains a novel 172 amino acid sequence that includes several structural motifs not present in STEP46. Amino acid sequencing revealed a number of potential phosphorylation sites in both STEP isoforms. Therefore, we investigated the role of phosphorylation in regulating STEP activity. Both STEP61and STEP46are phosphorylated on seryl residues by a cAMP-dependent protein kinase (PKA)-mediated pathway in striatal homogenates. The specific residues phosphorylated in STEP61were identified by site-directed mutagenesis and tryptic phosphopeptide mapping as Ser160 and Ser221, whereas the major site of phosphorylation in STEP46was shown to be Ser49. Ser160 is located within the unique N terminal of STEP61. Ser221 and Ser49 are equivalent residues present in STEP61and STEP46, respectively, and are located at the center of the kinase-interacting motif that has been implicated in protein–protein interactions. Phosphorylation at this site decreases the activity of STEPin vitroby reducing its affinity for its substrate.In vivostudies using striatal slices demonstrated that the neurotransmitter dopamine leads to the phosphorylation of STEP via activation of D1 receptors and PKA.
Erb and c-Kit Receptors Have Distinctive Patterns of Expression in Adult and Developing Taste Papillae and Taste Buds
Authors: McLaughlin Susan K.
Published: April 2018

Twenty four different protein tyrosine kinases (PTKs) were amplified from a taste-enriched cDNA library using PCR. The expression of four protein tyrosine kinase receptors (EGFR, ErbB2, ErbB3, and c-kit) was examined in adult and developing rat taste papillae. All four of these receptors were expressed in overlapping populations of differentiated taste cells within adult taste buds. Taste bud basal cells were ErbB2+but did not express the other Erb receptors. During prenatal development, the Erb receptors were expressed extensively in the basal cells around developing papillae, and ErbB2 and c-kit immunoreactive neuronal fibers were seen in close association with taste papillae. In early postnatal stages, ErbB2+and c-kit+neuronal fibers were often seen entering the taste papillae epithelium, where new taste buds form, and by postnatal day 2 (P2), individual ErbB2+and c-kit+cells were seen in this region as well. Between P3 and P8, c-kit was highly expressed at the bottom of foliate papillae trenches. The extensive expression of the Erb and c-kit receptors in adult taste buds and in and around developing papillae suggests that these receptors may play a role in the prenatal and postnatal development of gustatory papillae and taste buds.
Rescue of Locomotor Impairment in Dopamine D2 Receptor-Deficient Mice by an Adenosine A2A Receptor Antagonist
Authors: Aoyama Shiro , Kase Hiroshi , Borrelli Emiliana
Published: April 2018

In Parkinson's disease a degeneration of dopaminergic neurons of the nigrostriatal pathway is observed. Loss of dopaminergic regulation of striatal neuron activity results in altered motor functions. Adenosine A2A (A2AR) and dopamine D2 (D2R) receptors are colocalized in striatal medium spiny neurons. It has been proposed that adenosine binding to A2AR lowers the affinity of dopamine for D2R, thus modulating the function of this receptor. Absence of D2R in knockout mice (D2R−/−) results in impaired locomotion and coordinated movements. This indicates that absence of dopamine in Parkinson's disease might principally affect D2R-mediated effects with regard to locomotor functions. A2AR-selective antagonists have been demonstrated to have anti- parkinsonian activities in various models of Parkinson's disease in rodents and nonhuman primates. In this article, D2R−/− mice were used to explore the possibility that an A2AR antagonist might reestablish their motor impairment. Interestingly, blockade of A2AR rescues the behavioral parameters altered in D2R−/− mice. In addition, the level of expression of enkephalin and substance P, which were altered in D2R−/−, were also reestablished to normal levels after A2AR antagonist treatment. These results show that A2AR and D2R have antagonistic and independent activities in controlling neuronal and motor functions in the basal ganglia. They also provide evidence that selective A2AR antagonists can exhibit their anti-parkinsonian activities through a nondopaminergic mechanism.
The Representation of Retinal Blood Vessels in Primate Striate Cortex
Authors: Adams Daniel L. , Horton Jonathan C.
Published: April 2018

The blood vessels that nourish the inner retina cast shadows on photoreceptors, creating “angioscotomas” in the visual field. We have found the representations of angioscotomas in striate cortex of the squirrel monkey. They were detected in 9 of 12 normal adult animals by staining flatmounts for cytochrome oxidase activity after enucleation of one eye. They appeared as thin profiles in layer 4C radiating from the blind spot representation. Angioscotomas can be regarded as a local form of amblyopia. After birth, when light strikes the retina, photoreceptors beneath blood vessels are denied normal visual stimulation. This deprivation induces remodeling of geniculocortical afferents in a distribution that corresponds to the retinal vascular tree.

Angioscotoma representations were most obvious in monkeys with fine ocular dominance columns and were invisible in monkeys with large, well segregated columns. In monkeys without columns, their width corresponded faithfully to the inducing retinal shadow, making it possible to calculate the minimum shadow required to produce a cortical representation. The “amblyogenic threshold” was calculated as the fraction of the pupil area eclipsed to trigger remodeling of geniculocortical afferents. It was found to be constant over retinal eccentricity, vessel size, and shadow size. Ambliogenic shadows only three to four cones wide were sufficient to generate a cortical representation, testifying to the remarkable precision of the cortical map. The representations of retinal blood vessels separated by only 0.65° were resolvable in the cortex, yielding an upper limit on cortical resolution of 340 μm in layer 4C.
Free Radical Trap Phenyl-N-tert-Butylnitrone Protects against Light Damage But Does Not Rescue P23H and S334ter Rhodopsin Transgenic Rats from Inherited Retinal Degeneration
Authors: Ranchon Isabelle , LaVail Matthew M. , Kotake Yashige , Anderson Robert E.
Published: April 2018

Phenyl-N-tert-butylnitrone (PBN) protects rat retinas against light damage. Because the degenerative process involved in light damage and inherited retinal degeneration both lead to a common final cell death, apoptosis, we used transgenic rats with a P23H or S334ter rhodopsin mutation to test the effects of PBN on retinal degeneration and light damage and the susceptibility of the transgenic rats to light damage. In the first study, 3-week-old mutant and wild-type rats were given no drug, 0.25% PBN in drinking water, or 0.25% PBN in drinking water plus three daily intraperitoneal injections of PBN (100 mg/kg, i.p., every 8 hr). Electroretinograms were recorded at postnatal day 49, after which the rats were killed for morphometric analysis. There was no photoreceptor rescue by PBN in P23H or S334ter rats, as evidenced by equivalent loss of function and photoreceptor cells in the three treatment groups. In the second study, P23H, S334ter, and wild-type rats were exposed for 24 hr to 2700 lux light. The rats were untreated or treated with PBN (50 mg/kg per injection, every 6 hr, starting before exposure). ERGs were recorded before and 1 d after exposure. Animals were killed 6 d later for morphometric analysis. PBN protected wild-type and P23H but not S334ter retinas from light damage. S334ter retinas were relatively less susceptible to light damage than P23H and wild-type rats. The results suggest that the initiating event(s) that causes photoreceptor cell death in the mutated rats is different from that which occurs in light damage, although both ultimately undergo an apoptotic cell death.
Differential Pattern of cAMP Response Element-Binding Protein Activation in the Rat Brain after Conditioned Aversion as a Function of the Associative Process Engaged: Taste versus Context Association
Authors: Desmedt Aline , Hazvi Shoshi , Dudai Yadin
Published: April 2018

Ample data indicate that cAMP-response element-binding protein (CREB) is essential for the formation of long-term memory in various species and learning systems. This implies that activated CREB could delineate neuronal circuits that subserve items in memory, while leaving open the possibility that the specifics of CREB activation itself contribute to the specificity of the internal representation encoded by the relevant circuit. We describe here the differential activation of CREB in the rat brain as a function of two related yet distinct forms of aversive conditioning: conditioned taste aversion (CTA) and conditioned context aversion (CCA). We found that CTA induces strong CREB activation in the insular cortex (IC) and the lateral septum (LS), but not in the parietal cortex (PC) and the medial septum (MS). In contrast, CCA results in strong activation in the PC and MS, but not in the IC and LS. These findings are congruent with a model that links differential pattern of activity within the LS and the MS with the acquisition of elemental versus contextual conditioning and, more generally, with the notion that CREB activation delineates learning-dependent circuits as a function of the type of cognitive process engaged.
Collagen XIII Is Required for Neuromuscular Synapse Regeneration and Functional Recovery after Peripheral Nerve Injury
Authors: Zainul Zarin , Heikkinen Anne , Koivisto Hennariikka , Rautalahti Iina , Kallio Mika , Lin Shuo , Härönen Heli , Norman Oula , Rüegg Markus A. , Tanila Heikki , Pihlajaniemi Taina
Published: April 2018

Collagen XIII occurs as both a transmembrane-bound and a shed extracellular protein and is able to regulate the formation and function of neuromuscular synapses. Its absence results in myasthenia: presynaptic and postsynaptic defects at the neuromuscular junction (NMJ), leading to destabilization of the motor nerves, muscle regeneration and atrophy. Mutations inCOL13A1have recently been found to cause congenital myasthenic syndrome, characterized by fatigue and chronic muscle weakness, which may be lethal. We show here that muscle defects in collagen XIII-deficient mice stabilize in adulthood, so that the disease is not progressive until very late. Sciatic nerve crush was performed to examine how the lack of collagen XIII or forced expression of its transmembrane form affects the neuromuscular synapse regeneration and functional recovery following injury. We show that collagen XIII-deficient male mice are unable to achieve complete NMJ regeneration and functional recovery. This is mainly attributable to presynaptic defects that already existed in the absence of collagen XIII before injury. Shedding of the ectodomain is not required, as the transmembrane form of collagen XIII alone fully rescues the phenotype. Thus, collagen XIII could serve as a therapeutic agent in cases of injury-induced PNS regeneration and functional recovery. We conclude that intrinsic alterations at the NMJ inCol13a1−/−mice contribute to impaired and incomplete NMJ regeneration and functional recovery after peripheral nerve injury. However, such alterations do not progress once they have stabilized in early adulthood, emphasizing the role of collagen XIII in NMJ maturation.

SIGNIFICANCE STATEMENTCollagen XIII is required for gaining and maintaining the normal size, complexity, and functional capacity of neuromuscular synapses. Loss-of-function mutations inCOL13A1cause congenital myasthenic syndrome 19, characterized by postnatally progressive muscle fatigue, which compromises patients' functional capacity. We show here in collagen XIII-deficient mice that the disease stabilizes in adulthood once the NMJs have matured. This study also describes a relevant contribution of the altered NMJ morphology and function to neuromuscular synapses, and PNS regeneration and functional recovery in collagen XIII-deficient mice after peripheral nerve injury. Correlating the animal model data on collagen XIII-associated congenital myasthenic syndrome, it can be speculated that neuromuscular connections in congenital myasthenic syndrome patients are not able to fully regenerate and restore normal functionality if exposed to peripheral nerve injury.
IMPROVING CONCEPT MAPPING SKILL THROUGH INQUIRY INSTRUCTION
Authors: Gumilar S. , Setiawan W.
Published: April 2018

The purpose of this research was to analyze implementation of inquiry instruction for improving concept mapping skill. The subject of the research was student on grade 10 in islamic senior high school in subang district. Method of research used was quasy experiment with matching control group pretest-posttest design. Instruments used in this research were test and concept map about electricity. The treatment of experiment group was the combination of virtual-real experiment and virtual experiment, while control group was only real experiment method. The result of analyzing data showed that the average of normalized gain  was in low criteria. Significant test of three averages normalized gain using analysis of varians (anova) showed that virtual-real experiment method was more significant in improving mapping concept skill than those virtual experiment and real experiment only.Penelitian ini bertujuan untuk menganalisis penerapan pembelajaran inkuiri dalam meningkatkan ketrampilan membuat peta konsep. Subjek penelitian yang digunakan adalah siswa kelas X pada salah satu Sekolah Menengah Atas Islam Terpadu di Kabupaten Subang. Metode penelitian yang digunakan adalah Quasy experiment dengan desain penelitian matching control group pretest-posttest. Instrumen yang digunakan dalam penelitian ini adalah tes dan peta konsep mengenai kelistrikan. Kelas eksperimen dalam penelitian ini memperoleh perlakuan kombinasi metode eksperimen nyata-virtual dan virtual saja, sedangkan kelas kontrol memperoleh perlakuan metode eksperimen nyata saja. Hasil perhitungan rataan gain  yang ternormalisasi menunjukkan bahwa peningkatan kemampuan membuat peta konsep berada pada kriteria rendah. Hasil uji signifikansi ketiga rataan  menggunakan analysis of varians (ANOVA) menunjukkan bahwa metode eksperimen nyata-virtual lebih signifikan dalam meningkatkan keterampilan membuat peta konsep dibandingkan dengan metode eksperimen virtual saja dan nyata saja.
ONLINE-COURSE DEVELOPMENT VIA DISCUSSION-FORUM ON THE STUDENTS OF PHYSIC EDUCATION UNIVERSITAS NEGERI SEMARANG
Authors: Sudarwati I. , Khanafiyah S. , Sugiyanto S.
Published: April 2018

Students of Physic Education of Universitas Negeri Semarang often find some difficulties to understand the material. During difficult times, students usually find references on the internet,ask a friend who already understand, or ask a senior friend. Mostly students have a device that can be used to access the internet. Online-course via discussion-forum can be used as a discussion facility when they find difficulties to understand. Online-course via discussion-forum developed with ADDIE development models that includes the stages of analysis, design, development, implementation, and evaluation. Online-course discussion forum contains the list of courses that can be accessed by students via internet through the website discussion.belajarfisika.web.id. Feasibility of online course discussion forum was measured through assessment sheets of feasibility test from validators and questionnaire responses from students. The results of the feasibility test from the validator and student responses indicate that criteria are eligible. Results of the questionnaire about students' perceptions of learning through online course discussion forum show that Physic Education Students of Universitas Negeri Semarang have good perceptions of learning through online-course via discussion-forums.
The Effect of Inqury Based Learning on The Procedural Knowledge Dimension about Electric and Magnet Concept
Authors: Yusrizal Y. , Halim A. , Junike J.
Published: April 2018

The purpose of this study to determine the effect of the use of inquiry-based learning to the increased dimensions of procedural knowledge in electrical magnetic material. The study used a quasi-experimental research methods with research design is non-equivalent control group design and a sampel are selected with the random sampling method. The experimental group was taught by the method of inquiry-based learning and the control group was taught by conventional methods. Collecting data using the instrument of multiple-choice test that developed through this research with category of validity is valid, reliability with category of reliable, index of discrimination with category of low, and level of difficulty with category of medium. The results of the data analysis by using the formula N-Gain and t-test showed that an increase in the dimensions of procedural knowledge siginificantly for experimental class and less significant for control class. Based on the results of this study suggested to the teacher to always use the method of inquiry learning that an increase in procedural knowledge dimension, especially for topics related to experimental physics.
The Development of Questionnaire to Investigate Students� Attitudes and Approaches in Physics Problem Solving
Authors: Sirait J. , Sutrisno L. , Balta N. , Mason A.
Published: April 2018

This study aims to develop physics problem solving survey utilized to obtain students attitude and approach while solving physics problem. Several steps are conducted to develop the survey: validating, computing reliability, and testing. This research involves Physics Education students-Tanjungpura University who study at Fourth and Sixth semester. Furthermore, after questionnaire administered to the students, data are analysed through determining average score of the students and computing average percentage of students who are agree, neutral, and disagree based on semester and gender. The results show that the sixth semester students responses are more expertlike than those of the fourth semester students and female students are less expert than those male students. Based on semester and gender, majority of students have the same attitudes and approaches while solving problems. Students and experts have different attitudes about the role of mathematics in problem solving.
Impact of Learning Earth Litosphere using Interactive Conceptual Instruction on Logic Thinking, Conceptual Understanding, and Spiritual Aspect Embedding
Authors: Johan H. , Suhandi A. , Wulan A. R. , Sipriyadi S.
Published: April 2018

The aim of this study is to explore the impact of interactive-conceptual-instruction with visualization on logic thinking, conceptual understanding and spiritual aspect embedding. The sampling technique used in this research was convenience sampling. This research used mixed methods with embedded experiment design. The data of logic thinking and conceptual understanding was collected through pre-test and post-test. The questionnaires were used to collect data on spiritual attitudes and were analyzed qualitatively. The results showed that logic thinking-ability improves from no logic thinking to inductive-deductive logic thinking. The improvement of logic thinking abilities was in the medium category. Understanding the concept shifted from incompetent to conceptual understanding with improvement, in the medium category. The questionnaires analysis showed that the students got spiritual values related to the awareness of God believing behind the natural phenomena that impact on their spiritual attitudes. This study also tried to apply the results of pure science research to support learning activities. Based on the result of the research, it can be concluded that the learning process using interactive conceptual with visualization can improve logic thinking, conceptual comprehension, and spiritual attitude embeding.
Murine sperm capacitation, oocyte penetration and decondensation following moderate alcohol intake
Authors: Sánchez Melisa C , Fontana Vanina A , Galotto Camila , Cambiasso Maite Y , Sobarzo Cristian M A , Calvo Lucrecia , Calvo Juan C , Cebral Elisa
Published: April 2018

Male chronic alcohol abuse causes testicular failure and infertility. We analyzed the effects of moderate sub-chronic alcohol intake on sperm morphology, capacitation, fertilization and sperm head decondensation. CF-1 male mice were administered 15% ethanol in drinking water for 15 days; control mice received ethanol-free water. Similar patterns of tyrosine phosphorylation were observed in capacitated spermatozoa of control and treated males. Percentage of hyperactivation (H) and spontaneous (SAR) and progesterone-induced (IAR) acrosome reaction significantly decreased at 120 and 150 min of capacitation in treated males compared to controls (H: 14.1 ± 2.5 vs 23.7 ± 2.6,P < 0.05; SAR-T120 min: 17.9 ± 2.5 vs 32.9 ± 4.1,P < 0.01; IAR-150 min: 43.3 ± 3.5 vs 73.1 ± 1.1,P < 0.001,n = 6). Duringin vitrofertilization (2.5, 3.5 and 4.5 h post-insemination), there was an increased percentage of fertilized oocytes (with a decondensed sperm head and one or two pronuclei) in treated males (P < 0.001,n = 7). After 60 min ofin vitrodecondensation with glutathione plus heparin, the percentage of decondensed sperm heads was significantly higher in treated males than in controls (mean ± s.d.: 57.1 ± 5.6 vs 48.3 ± 4.5,P < 0.05,n = 5). The percentage of morphologically normal sperm heads was significantly decreased in treated males with respect to controls (P < 0.001,n = 9). These results show that short-term moderate alcohol consumption in outbred mice affect sperm morphology, hyperactivation, acrosomal exocytosis, and the dynamics ofin vitrofertilization andin vitrosperm nuclear decondensation.