In a Pickle: Is Cornichon Just Relish or Part of the Main Dish?

The recent discovery that vertebrate homologs of Drosophila cornichon associate with AMPA receptors led to the unexpected notion that cornichons play a role in synaptic transmission. In this issue of Neuron, Kato et al. find that cornichons modulate the gating of TARP-associated AMPA receptors by preventing their resensitization to glutamate

Wind tunnel tests to obtain train aerodynamic drag coefficients: Reynolds number and ground simulation effects

Summary An assessment is made of the effect of different types of ground simulation on wind tunnel measurements of the aerodynamic drag of trains, together with an assessment of Reynolds number effects which must be considered when extrapolating from model scale to full scale values. Drag coefficients are considered for two train types, the French TGV001 and the British HST. It is shown that the errors involved in extrapolating values of drag coefficient from model scale to full scale are significantly greater than possible errors caused by inadequate ground simulation. These extrapolation errors seem to be due to significant three-dimensionality in the train boundary layers, and it is suggested that these effects warrant further research

Racial and cultural minority experiences and perceptions of health care provision in a mid-western region

© 2018 The Author(s). Background: Disparities across a number of health indicators between the general population and particular racial and cultural minority groups including African Americans, Native Americans and Latino/a Americans have been well documented. Some evidence suggests that particular groups may receive poorer standards of care due to biased beliefs or attitudes held by health professionals. Less research has been conducted in specifically non-urban areas with smaller minority populations. Methods: This study explored the self-reported health care experiences for 117 racial and cultural minority Americans residing in a Mid-Western jurisdiction. Prior health care experiences (including perceived discrimination), attitudes towards cultural competence and satisfaction with health care interactions were ascertained and compared across for four sub-groups (African-American, Native American, Latino/a American, Asian American). A series of multiple regression models then explored relationships between a concert of independent variables (cultural strength, prior experiences of discrimination, education level) and health care service preferences and outcomes. Results: Overall, racial/cultural minority groups (African Americans, Native Americans, Latino/a Americans, and Asian Americans) reported general satisfaction with current healthcare providers, low levels of both health care provider racism and poor treatment, high levels of cultural strength and good access to health care services. Native American participants however, reported more frequent episodes of poor treatment compared to other groups. Incidentally, poor treatment predicted lower levels of treatment satisfaction and racist experiences predicted being afraid of attending conventional health care services. Cultural strength predicted a preference for consulting a health care professional from the same cultural background. Conclusions: This study provided a rare insight into minority health care expectations and experiences in a region with comparatively lower proportions of racial and cultural minorities. Additionally, the study explored the impact of cultural strength on health care interactions and outcomes. While the bulk of the sample reported satisfaction with treatment, the notable minority of participants reporting poor treatment is still of some concern. Cultural strength did not appear to impact health care behaviours although it predicted a desire for cultural matching. Implications for culturally competent health care provision are discussed within

Free-induction-decay magnetometer based on a microfabricated Cs vapor cell

We describe an optically pumped Cs magnetometer containing a 1.5 mm thick microfabricated vapor cell with nitrogen buffer gas operating in a free-induction-decay (FID) configuration. This allows us to monitor the free Larmor precession of the spin coherent Cs atoms by separating the pump and probe phases in the time domain. A single light pulse can sufficiently polarize the atomic sample however, synchronous modulation of the light field actively drives the precession and maximizes the induced spin coherence. Both amplitude and frequency modulation have been implemented with noise floors of 3 pT / √ Hz and 16 pT / √ Hz respectively within the Nyquist limited bandwidth of 500 Hz

Neuronal Activity and CaMKII Regulate Kinesin-Mediated Transport of Synaptic AMPARs

SummaryExcitatory glutamatergic synaptic transmission is critically dependent on maintaining an optimal number of postsynaptic AMPA receptors (AMPARs) at each synapse of a given neuron. Here, we show that presynaptic activity, postsynaptic potential, voltage-gated calcium channels (VGCCs) and UNC-43, the C. elegans homolog of CaMKII, control synaptic strength by regulating motor-driven AMPAR transport. Genetic mutations in unc-43, or spatially and temporally restricted inactivation of UNC-43/CaMKII, revealed its essential roles in the transport of AMPARs from the cell body and in the insertion and removal of synaptic AMPARs. We found that an essential target of UNC-43/CaMKII is kinesin light chain and that mouse CaMKII rescued unc-43 mutants, suggesting conservation of function. Transient expression of UNC-43/CaMKII in adults rescued the transport defects, while optogenetic stimulation of select synapses revealed CaMKII’s role in activity-dependent plasticity. Our results demonstrate unanticipated, fundamentally important roles for UNC-43/CaMKII in the regulation of synaptic strength

An imaging system for standardized quantitative analysis of C. elegans behavior

BACKGROUND: The nematode Caenorhabditis elegans is widely used for the genetic analysis of neuronal cell biology, development, and behavior. Because traditional methods for evaluating behavioral phenotypes are qualitative and imprecise, there is a need for tools that allow quantitation and standardization of C. elegans behavioral assays. RESULTS: Here we describe a tracking and imaging system for the automated analysis of C. elegans morphology and behavior. Using this system, it is possible to record the behavior of individual nematodes over long time periods and quantify 144 specific phenotypic parameters. CONCLUSIONS: These tools for phenotypic analysis will provide reliable, comprehensive scoring of a wide range of behavioral abnormalities, and will make it possible to standardize assays such that behavioral data from different labs can readily be compared. In addition, this system will facilitate high-throughput collection of phenotypic data that can ultimately be used to generate a comprehensive database of C. elegans phenotypic information. AVAILABILITY: The hardware configuration and software for the system are available from [email protected]

Masting by Eighteen New Zealand Plant Species: The Role of Temperature as a Synchronizing Cue

Masting, the intermittent production of large flower or seed crops by a population of perennial plants, can enhance the reproductive success of participating plants and drive fluctuations in seed-consumer populations and other ecosystem components over large geographic areas. The spatial and taxonomic extent over which masting is synchronized can determine its success in enhancing individual plant fitness as well as its ecosystem-level effects, and it can indicate the types of proximal cues that enable reproductive synchrony. Here, we demonstrate high intra- and intergeneric synchrony in mast seeding by 17 species of New Zealand plants from four families across \u3e150000 km2. The synchronous species vary ecologically (pollination and dispersal modes) and are geographically widely separated, so intergeneric synchrony seems unlikely to be adaptive per se. Synchronous fruiting by these species was associated with anomalously high temperatures the summer before seedfall, a cue linked with the La Niña phase of El Niño–Southern Oscillation. The lone asynchronous species appears to respond to summer temperatures, but with a 2-yr rather than 1-yr time lag. The importance of temperature anomalies as cues for synchronized masting suggests that the timing and intensity of masting may be sensitive to global climate change, with widespread effects on taxonomically disparate plant and animal communities

MAGI-1 Modulates AMPA Receptor Synaptic Localization and Behavioral Plasticity in Response to Prior Experience

It is well established that the efficacy of synaptic connections can be rapidly modified by neural activity, yet how the environment and prior experience modulate such synaptic and behavioral plasticity is only beginning to be understood. Here we show in C. elegans that the broadly conserved scaffolding molecule MAGI-1 is required for the plasticity observed in a glutamatergic circuit. This mechanosensory circuit mediates reversals in locomotion in response to touch stimulation, and the AMPA-type receptor (AMPAR) subunits GLR-1 and GLR-2, which are required for reversal behavior, are localized to ventral cord synapses in this circuit. We find that animals modulate GLR-1 and GLR-2 localization in response to prior mechanosensory stimulation; a specific isoform of MAGI-1 (MAGI-1L) is critical for this modulation. We show that MAGI-1L interacts with AMPARs through the intracellular domain of the GLR-2 subunit, which is required for the modulation of AMPAR synaptic localization by mechanical stimulation. In addition, mutations that prevent the ubiquitination of GLR-1 prevent the decrease in AMPAR localization observed in previously stimulated magi-1 mutants. Finally, we find that previously-stimulated animals later habituate to subsequent mechanostimulation more rapidly compared to animals initially reared without mechanical stimulation; MAGI-1L, GLR-1, and GLR-2 are required for this change in habituation kinetics. Our findings demonstrate that prior experience can cause long-term alterations in both behavioral plasticity and AMPAR localization at synapses in an intact animal, and indicate a new, direct role for MAGI/S-SCAM proteins in modulating AMPAR localization and function in the wake of variable sensory experience

Calcineurin and Protein kinase G regulate C. elegans behavioral quiescence during locomotion in liquid

<p>Abstract</p> <p>Background</p> <p>Most rhythmic motor behaviors in nature are episodic i.e. they alternate between different behavioral states, including quiescence. Electrophysiological studies in invertebrate behavioral switching, maintenance and quiescence have elucidated several neuronal mechanisms that generate a temporal pattern in behavior. However, the genetic bases of these processes are less well studied. We have previously uncovered a novel episodic behavior exhibited by <it>C. elegans </it>in liquid media where they alternate between distinct phases of rhythmic swimming and quiescence. Here, we have investigated the effect of several genes and their site of action on the behavioral quiescence exhibited in liquid by the nematode <it>C. elegans</it>.</p> <p>Results</p> <p>We have previously reported that high cholinergic signaling promotes quiescence and command interneurons are critical for timing the quiescence bout durations. We have found that in addition to command interneurons, sensory neurons are also critical for quiescence. We show that the protein phosphatase calcineurin homolog <it>tax-6 </it>promotes swimming whereas the protein kinase G homolog <it>egl-4 </it>promotes quiescence. <it>tax-6 </it>expression in the sensory neurons is sufficient to account for its effect. <it>egl-4 </it>also acts in multiple sensory neurons to mediate its effect on quiescence. In addition our data is consistent with regulation of quiescence by <it>egl-4 </it>acting functionally downstream of release of acetylcholine (ACh) by motor neurons.</p> <p>Conclusions</p> <p>Our study provides genetic evidence for mechanisms underlying the maintenance of a behavioral state operating at multiple neuronal levels through the activities of a kinase and a phosphatase. These results in a genetically tractable organism establish a framework for further dissection of the mechanism of quiescence during episodic behaviors.</p