bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of BKCa channel activity by association with calcineurin in rat brain
Authors: Loane David J. , Hicks Gareth A. , Perrino Brian A. , Marrion Neil V. 
Published: July 2006

AbstractLarge conductance calcium‐activated potassium (BKCa) channels are regulated by a number of different protein kinases and phosphatases. The close association of enzymes and channel have been shown to underlie many examples of modulation. However, only the association of protein kinase A with the BKCa channel has been detailed [Tian et al. (2003)J. Biol. Chem., 278, 8669–8677]. We have found using reciprocal immunoprecipitations that the BKCa channel associates with the calcium/calmodulin‐dependent phosphatase calcineurin, in Wistar rat brain. A HA‐tagged construct of the carboxyl terminus of rSlo27, a variant of the BKCa channel that is abundant in the hippocampus [Ha et al. (2000)Eur. J. Biochem., 267, 910–9218], was found to associate only with the B subunit of calcineurin. This data suggests that the majority of the interaction of the BKCa channel with calcineurin is mediated by the B subunit of the phosphatase. This was confirmed by using glutathione‐S‐transferase (GST) fusion proteins of the linker regions between the S7–S10 hydrophobic domains in the carboxyl terminus of rSlo27, where only the B subunit of calcineurin interacted with regions between S7 and S9 of the channel. Addition of a constitutively active calcineurin (CaN420) to inside‐out membrane patches excised from cultured hippocampal neurons resulted in a dramatic reduction in BKCa channel open probability, with only very short‐duration events being apparent. These data suggest that BKCa channel activity is inhibited by calcineurin, an effect mediated by the association of the calcineurin B subunit with the carboxyl terminus of the channel.
Immunolocalization of BK channels in hippocampal pyramidal neurons
Authors: Sailer Claudia A. , Kaufmann Walter A. , Kogler Michaela , Chen Lie , Sausbier Ulrike , Ottersen Ole Petter , Ruth Peter , Shipston Michael J. , Knaus Hans‐Günther 
Published: July 2006

AbstractNeurons are highly specialized cells in which the integration and processing of electrical signals critically depends on the precise localization of ion channels. For large‐conductance Ca2+‐ activated K+ (BK) channels, targeting to presynaptic membranes in hippocampal pyramidal cells was reported; however, functional evidence also suggests a somatodendritic localization. Therefore we re‐examined the subcellular distribution of BK channels in mouse hippocampus using a panel of independent antibodies in a combined approach of conventional immunocytochemistry on cultured neurons, pre‐ and postembedding electron microscopy and immunoprecipitation. In cultured murine hippocampal neurons, the colocalization of BK channels with both pre‐ and postsynaptic marker proteins was observed. Electron microscopy confirmed targeting of BK channels to axonal as well as dendritic membranes of glutamatergic synapses in hippocampus. A postsynaptic localization of BK channels was also supported by the finding that the channel coimmunoprecipitated with PSD95, a protein solely expressed in the postsynaptic compartment. These results thus demonstrate that BK channels reside in both post‐ and presynaptic compartments of hippocampal pyramidal neurons.
Partial inhibition of PP1 alters bidirectional synaptic plasticity in the hippocampus
Authors: Jouvenceau Anne , Hédou Gael , Potier Brigitte , Kollen Mélanie , Dutar Patrick , Mansuy Isabelle M. 
Published: July 2006

AbstractSynaptic plasticity is an important cellular mechanism that underlies memory formation. In brain areas involved in memory such as the hippocampus, long‐term synaptic plasticity is bidirectional. Major forms of bidirectional plasticity encompass long‐term potentiation (LTP), LTP reversal (depotentiation) and long‐term depression (LTD). Protein kinases and protein phosphatases are important players in the induction of both LTP and LTD, and the serine/threonine protein phosphatase‐1 (PP1), in particular, has emerged as a key phosphatase in these processes. The goal of the present study was to assess the contribution of PP1 to bidirectional plasticity and examine the impact of a partial inhibition of PP1 on LTP, LTD and depotentiation in the mouse hippocampus. For this, we used transgenic mice expressing an active PP1 inhibitor (I‐1*) inducibly in forebrain neurons. We show that partial inhibition of PP1 by I‐1* expression alters the properties of bidirectional plasticity by inducing a shift of synaptic responses towards potentiation. At low‐frequency stimulation, PP1 inhibition decreases LTD in a frequency‐dependent fashion. It favours potentiation over depression at intermediate frequencies and increases LTP at high frequency. Consistently, it also impairs depotentiation. These results indicate that the requirement of bidirectional plasticity for PP1 is frequency‐dependent and that a broad range of plasticity is negatively constrained by PP1, a feature that may correlate with the property of PP1 to constrain learning efficacy and promote forgetting.
A novel type of cold‐sensitive neuron in rat dorsal root ganglia with rapid adaptation to cooling stimuli
Authors: Babes Alexandru , Zorzon Daniel , Reid Gordon 
Published: July 2006

AbstractCold sensing in mammals is heterogeneous and more than one type of receptor molecule is likely to be involved in the transduction process. Most features of innocuous cold receptors have been explained by TRPM8, the cold and menthol receptor, but their fast adaptation to cooling has not yet been reproduced in cellular systems. In this study we have used a newly developed system for applying fast thermal stimuli to dissociated dorsal root ganglia (DRG) neurons from young rats (150–200 g) in primary culture. We describe a novel type of cold‐sensitive rat DRG neuron with rapid adaptation to cooling. These cells (4.3% of the total DRG population) do not express either TRPM8 or the other cold‐activated TRP channel, TRPA1, and the epithelial sodium channel (ENaC) is not involved in their transduction. Increases in intracellular calcium induced by cooling in rapidly adapting neurons are caused by calcium entry. These neurons express a large and rapidly adapting cold‐induced inward current with a time constant of adaptation in the seconds range, and may correspond to the rapidly adapting cold receptors described in vivo.
Attenuating corticosterone levels on the day of memory assessment prevents chronic stress‐induced impairments in spatial memory
Authors: Wright Ryan L. , Lightner Elizabeth N. , Harman James S. , Meijer Onno C. , Conrad Cheryl D. 
Published: July 2006

AbstractThis study investigated whether chronic stress‐induced spatial memory deficits were caused by changes in the hypothalamic‐pituitary‐adrenal axis, such as corticosterone (CORT) elevations on the day of memory assessment, rather than the consequence of structural changes in the hippocampus. Male Sprague–Dawley rats were restrained for 6 h/day/21 days, and spatial memory was assessed on the Y‐maze on day 22. Ninety minutes before training, rats received a subcutaneous injection of vehicle or metyrapone, a CORT synthesis inhibitor, and then spatial memory was determined 4‐h later. The highest dose of metyrapone (75 mg/kg, s.c.) was most effective at preventing stress‐induced spatial memory deficits. Chronic stress increased total CORT levels following Y‐maze exposure, while acute metyrapone treatment dose‐dependently attenuated total and free (unbound) CORT levels in both stress and control conditions. Blood samples taken from a separate subset of chronically stressed rats showed that baseline CORT levels were similar across the restraint period. Finally, chronic stress down‐regulated glucocorticoid, but not mineralocorticoid, receptor mRNA expression within the hippocampus (dentate gyrus, CA1, CA2, CA3). These findings suggest that chronic stress‐induced spatial memory deficits may be mediated by hypothalamic‐pituitary‐adrenal axis dysregulation. Specifically, CORT elevations and reductions in hippocampal glucocorticoid receptor expression, at the time of behavioural assessment may be involved, as opposed to a direct effect that is solely dependent upon hippocampal structural changes. These results have significance for treating cognitive decline in conditions associated with elevated glucocorticoids that include subpopulations in ageing, depression, Cushing's disease and Alzheimer's disease.
A context‐specific single contingent‐reinforcing stimulus boosts intermediate‐term memory into long‐term memory
Authors: Parvez Kashif , Moisseev Victor , Lukowiak Ken 
Published: July 2006

AbstractFollowing operant conditioning of aerial respiration in Lymnaea, memory forms. Depending on the training procedure either intermediate memory (ITM, < 3 h) or long‐term memory (LTM, > 6 h) results. ITM is dependent on de novo protein synthesis whilst LTM is dependent on both transcription and de novo protein synthesis. LTM formation requires the soma of RPeD1 (one of the central pattern generator neurons) to be present. Following activation of a memory, it re‐enters a labile state and undergoes a reconsolidation process to restabilize it. During reconsolidation, memory may be updated and/or changed. We add here another consequence of memory reactivation: a single contingent‐reinforcing stimulus (SCRS), given in the same context as previous ITM training, boosts a residual memory trace to LTM. Separate cohorts of snails first received the ITM training procedure. In the cohort that received the SCRS 24 h after the last ITM training session, LTM was observed on the following day. LTM was not observed in cohorts that were: (i) given a single noncontingent stimulus; (ii) given the SCRS in a context other than the ITM training; (iii) given a 48‐h gap between the last ITM training session and the context‐specific SCRS; (iv) cooled immediately after the last ITM training session; (v) cooled immediately after the delivery of the context‐specific SCRS; (vi) had the soma of RPeD1 ablated before the presentation of the context‐specific SCRS; (vii) received a yoked control procedure. These data lead us to conclude that the context‐specific SCRS reactivates a residual molecular memory trace in RPeD1 and boosts it into becoming the substrate for LTM.
Cyanobacterial assimilatory nitrate reductase gene diversity in coastal and oligotrophic marine environments
Authors: Jenkins Bethany D. , Zehr Jonathan P. , Gibson Angela , Campbell Lisa 
Published: July 2006

SummaryCyanobacteria are important primary producers in many marine ecosystems and their abundances and growth rates depend on their ability to assimilate various nitrogen sources. To examine the diversity of nitrate‐utilizing marine cyanobacteria, we developed PCR primers specific for cyanobacterial assimilatory nitrate reductase (narB) genes. We obtained amplification products from diverse strains of cultivated cyanobacteria and from several marine environments. Phylogenetic trees constructed with the narB gene are congruent with those based on ribosomal RNA genes and RNA polymerase genes. Analysis of sequence library data from coastal and oligotrophic marine environments shows distinct groups of Synechococcus sp. in each environment; some of which are represented by sequences from cultivated organisms and others that are unrelated to known sequences and likely represent novel phylogenetic groups. We observed spatial differences in the distribution of sequences between two sites in Monterey Bay and differences in the vertical distribution of sequence types at the Hawai’i Ocean Time‐series Station ALOHA, suggesting that nitrogen assimilation in Synechococcus living in different ecological niches can be followed with the nitrate reductase gene.
Presence of Hydrogenophilus thermoluteolus DNA in accretion ice in the subglacial Lake Vostok, Antarctica, assessed using rrs, cbb and hox
Authors: Lavire Céline , Normand Philippe , Alekhina Irina , Bulat Serguey , Prieur Daniel , Birrien Jean‐Louis , Fournier Pascale , Hänni Catherine , Petit Jean‐Robert 
Published: July 2006

SummaryThe 3561 m Vostok ice core sample originating from the subglacial Lake Vostok accretion (frozen lake water) ice with sediment inclusions was thoroughly studied by various means to confirm the presence of the thermophile bacterium Hydrogenophilus thermoluteolus reported earlier in the 3607 m accretion ice sample. PCR and molecular‐phylogenetic analyses performed in two independent laboratories were made using different 16S rRNA gene (rrs) targeted primers. As a result, rrs‐targeted PCR permitted to recover several very closely related clones with a small genetic distance to Hydrogenophilus thermoluteolus (< 1%). In addition, RubisCO (cbbL or rbcL) and NiFe‐Hydrogenase (hoxV or hupL) targeted PCR have also allowed to recover sequences highly related to Hydrogenophilus thermoluteolus. All these results point to the presence of thermophilic chemoautotrophic microorganisms in Lake Vostok accretion ice. They presumably originate from deep faults in the bedrock cavity containing the lake in which episodes of seismotectonic activity would release debris along with microbial cells.
OxyR regulated the expression of two major catalases, KatA and KatB, along with peroxiredoxin, AhpC in Pseudomonas putida
Authors: Hishinuma Sota , Yuki Masahiro , Fujimura Makoto , Fukumori Fumiyasu 
Published: July 2006

SummaryOxyR is known to activate/repress the expression of the oxyR regulon, which consists of several genes, which play important antioxidant role in Escherichia coli. To elucidate the role of OxyR in Pseudomonas putida KT2442, the oxyR1 mutation that caused the upregulation of ahpC in a toluene‐resistant variant strain was introduced, because no null mutants in oxyR were isolated. This mutation was shown to cause the accumulation of a catalase (KatA) along with AhpC throughout the growth, and of a RpoS‐dependent catalase/peroxidase (KatB) in the stationary phase. Following the identification of the transcription start site of two catalase genes, sequences similar to those involved in the proposed OxyR binding for E. coli were found upstream from each of the promoter regions of katA and katB, as well as ahpC. Purified OxyR was shown to bind to these sequences, under both reduced and oxidized states. Moreover, the oxyR1 mutation increased the transcription levels of these genes. These results are consistent with the conclusion, distinct from those observed in an opportunistic pathogen Pseudomonas aeruginosa, that OxyR controlled expression of all the principal peroxide‐degrading enzymes in P. putida. The mutation did not cause any notable changes in the transcriptional levels of several antioxidant genes, including those of glutathione reductase, glutaredoxins and thioredoxins, which would involve maintenance of the cellular thiol‐disulfide balance, suggesting that the transcriptional regulation of these antioxidant genes should be different from that of katA, katB and ahpC in P. putida.
Cultivation‐independent analysis of Pseudomonas species in soil and in the rhizosphere of field‐grown Verticillium dahliae host plants
Authors: Costa Rodrigo , Salles Joana Falcão , Berg Gabriele , Smalla Kornelia 
Published: July 2006

SummaryDespite their importance for rhizosphere functioning, rhizobacterial Pseudomonas spp. have been mainly studied in a cultivation‐based manner. In this study a cultivation‐independent method was used to determine to what extent the factors plant species, sampling site and year‐to‐year variation influence Pseudomonas community structure in bulk soil and in the rhizosphere of two Verticillium dahliae host plants, oilseed rape and strawberry. Community DNA was extracted from bulk and rhizosphere soil samples of flowering plants collected at three different sites in Germany in two consecutive years. Pseudomonas community structure and diversity were assessed using a polymerase chain reaction denaturing gradient gel electrophoresis (PCR‐DGGE) system to fingerprint Pseudomonas‐specific 16S rRNA gene fragments amplified from community DNA. Dominant and differentiating DGGE bands were excised from the gels, cloned and sequenced. The factors sampling site, plant species and year‐to‐year variation were shown to significantly influence the community structure of Pseudomonas in rhizosphere soils. The composition of Pseudomonas 16S rRNA gene fragments in the rhizosphere differed from that in the adjacent bulk soil and the rhizosphere effect tended to be plant‐specific. The clone sequences of most dominant bands analysed belonged to the Pseudomonas fluorescens lineage and showed closest similarity to culturable Pseudomonas known for displaying antifungal properties. This report provides a better understanding of how different factors drive Pseudomonas community structure and diversity in bulk and rhizosphere soils.
‘Pitted but not pitied’ or, does smallpox make you small?1
Authors: OXLEY DEBORAH 
Published: July 2006

SUMMARYThis article examines three propositions put by Leunig and Voth: that smallpox reduced stature irrespective of location, that stunting was most apparent among adolescents, and that these relationships were obscured in my earlier work by small sample size. It tests these claims by re‐examining the original data—including the neglected Wandsworth data set—and questioning the meaning of the chosen method of graphical representation. Furthermore, and most fundamentally, the relationship between smallpox and stunting is advanced by adding new data on a further 34,310 prisoners. Using considerably larger data sets with many more juveniles, and refined definitions of rural and urban locations, this article confirms that the ‘smallpox effect’ varied by location, age, gender, and time period. That the relationship between smallpox and stunting was mediated through place and time suggests the role played by evolving urban conditions. The article offers a warning on the dangers of aggregating data without paying heed to important composition effects, and it argues that size does matter: the size of the smallpox effect, population size, sample size, and the size of the p‐statistic. The reply concludes by again questioning the likely causes of stunting in the world’s first great metropolis, London, arguing for the importance of examining chronic illness as a source of ongoing nutritional insult.
Epilepsy as a Consequence of Cerebral Malaria in Area in Which Malaria Is Endemic in Mali, West Africa
Authors: Ngoungou Edgard Brice , Dulac Olivier , Poudiougou Belco , Druet‐Cabanac Michel , Dicko Alassane , Mamadou Traore Abdoulaye , Coulibaly Drissa , Farnarier Guy , Tuillas Maryse , Keita Marouf Mamadou , Kombila Maryvonne , Doumbo Ogobara K. , Preux Pierre‐Marie 
Published: July 2006

Summary:  Purpose: Cerebral malaria (CM) is suspected to be a potential cause of epilepsy in tropical areas, but little information is available. The purpose of this study was to evaluate the role of CM in epilepsy among children in Mali.  Methods: An exposed–nonexposed study was performed to identify children who had epilepsy after malaria in the 0‐ to 15‐year age group. The exposure factor was CM defined according to World Health Organization (WHO) criteria, and the nonexposure factor was symptomatic malaria without the characteristics of CM (NCM). All the children underwent a screening questionnaire and were examined by a medical physician. After the screening phase, a specialist in neuropediatrics examined the children suspected to have epilepsy. EEG and computed tomography (CT) scans were performed in some of these patients.  Results: In total, 101 subjects who had had CM and 222 who had had NCM were included. Fifty‐four children (CM, 34; NCM, 20) were suspected to have epilepsy, and six were confirmed (CM, five; NCM, one). The incidence rate was 17.0 per 1000 person‐years in the CM group and 1.8 per 1000 person‐year in the NCM group; thus the relative risk (RR) was 9.4 [95% confidence interval (CI), 1.3–80.3; p = 0.02]. After adjustment on age and duration of follow‐up, the RR was 14.3 (95% CI, 1.6–132.0; p = 0.01).  Conclusions: The risk of sequelar epilepsy is significantly higher in the CM group compared with the NCM group. A reevaluation of this cohort should be carried out later to search for temporal epilepsy that appeared after age 10 years.
Authority and Commitment: Why Universities, Like Legislatures, Are Not Organized as Firms
Authors: Masten Scott E. 
Published: July 2006

This paper explores the functions and limitations of democratic governance by analyzing the allocation of decision‐making authority in colleges and universities. Contrary to the conventional perception that large numbers and heterogeneity of voters and issues undermine the efficiency of democratic decision making, data on the allocation of authority for thirty‐one decision areas in 826 US colleges and universities show democratic governance to be more prevalent in larger, “full‐service” research universities than in smaller liberal arts colleges and special‐curriculum institutions. State‐ and church‐affiliated institutions, meanwhile, tend to be governed more like firms. The results overall are consistent with economic theories of political organization that view democratic governance primarily as a means of enhancing the credibility of commitments rather than as a method of aggregating preferences.“Educational systems, like governments, apparently can never be rational, never a logical and economical means to a definite end. Rather must they be always makeshifts.”—J.P. Munroe (1899)“Never did a dean lack legitimate reasons by which to color his bad faith”—Machiavelli, The Dean (1513)
A Randomized Trial of Olfactory Stimulation Using Black Pepper Oil in Older People with Swallowing Dysfunction
Authors: Ebihara Takae , Ebihara Satoru , Maruyama Masahiro , Kobayashi Mitsuru , Itou Azusa , Arai Hiroyuki , Sasaki Hidetada 
Published: July 2006

OBJECTIVES: To determine the effect of olfactory stimulation with volatile black pepper oil (BPO) on risk factors for pneumonia.DESIGN: A 1‐month randomized, controlled study.SETTING: Nursing homes in Japan that serve as long‐term care facilities for older residents who are physically handicapped, mainly because of cerebrovascular disease.PARTICIPANTS: One hundred five poststroke residents.MEASUREMENTS: Latency of the swallowing reflex (LTSR), the number of swallowing movements, serum substance P (SP), and regional cerebral blood flow (rCBF).RESULTS: Nasal inhalation of BPO for 1 minute shortened LTSR, compared with that of lavender oil and distilled water (P<.03). Compared with the period before the study, the 1‐month intervention using BPO improved LTSR with an increase of serum SP (P<.01). The number of swallowing movements for 1 minute during the nasal inhalation of BPO increased (P<.001). Multiple comparisons showed a poststudy increase in rCBF within the insular cortex (P<.001). Compared with the prestudy rCBF, BPO intervention increased rCBF in the right orbitofrontal and left insular cortex (P<.001).CONCLUSION: Inhalation of BPO, which can activate the insular or orbitofrontal cortex, resulting in improvement of the reflexive swallowing movement, might benefit older poststroke patients with dysphagia regardless of their level of consciousness or physical and mental status.