Rapid Earthquake Characterization Using MEMS Accelerometers and Volunteer Hosts Following the M 7.2 Darfield, New Zealand, Earthquake

We test the feasibility of rapidly detecting and characterizing earthquakes with the Quake‐Catcher Network (QCN) that connects low‐cost microelectromechanical systems accelerometers to a network of volunteer‐owned, Internet‐connected computers. Following the 3 September 2010 M 7.2 Darfield, New Zealand, earthquake we installed over 180 QCN sensors in the Christchurch region to record the aftershock sequence. The sensors are monitored continuously by the host computer and send trigger reports to the central server. The central server correlates incoming triggers to detect when an earthquake has occurred. The location and magnitude are then rapidly estimated from a minimal set of received ground‐motion parameters. Full seismic time series are typically not retrieved for tens of minutes or even hours after an event. We benchmark the QCN real‐time detection performance against the GNS Science GeoNet earthquake catalog. Under normal network operations, QCN detects and characterizes earthquakes within 9.1 s of the earthquake rupture and determines the magnitude within 1 magnitude unit of that reported in the GNS catalog for 90% of the detections

Cannabinoid receptor-interacting protein Crip1a modulates CB1 receptor signaling in mouse hippocampus

The online version of this article (doi:10.1007/s00429-015-1027-6) contains supplementary material, which is available to authorized users.This work was supported by the Deutsche Forschungsgemeinschaft FOR926 (subprojects SP3 to B. L. and K. M.), SFB 1080 (subprojects A1 to H. J. L. and B8 to B. L.), the Australian Research Council (ARC Future Fellowship to M. K.), the Hungarian Brain Research Program, KTIA_NAP_13-2-2014-0013 (to A.A.), the Swedish Medical Research Council and the Novo Nordisk Foundation (T. H.

Administration of Thimerosal to Infant Rats Increases Overflow of Glutamate and Aspartate in the Prefrontal Cortex: Protective Role of Dehydroepiandrosterone Sulfate

Thimerosal, a mercury-containing vaccine preservative, is a suspected factor in the etiology of neurodevelopmental disorders. We previously showed that its administration to infant rats causes behavioral, neurochemical and neuropathological abnormalities similar to those present in autism. Here we examined, using microdialysis, the effect of thimerosal on extracellular levels of neuroactive amino acids in the rat prefrontal cortex (PFC). Thimerosal administration (4 injections, i.m., 240 μg Hg/kg on postnatal days 7, 9, 11, 15) induced lasting changes in amino acid overflow: an increase of glutamate and aspartate accompanied by a decrease of glycine and alanine; measured 10–14 weeks after the injections. Four injections of thimerosal at a dose of 12.5 μg Hg/kg did not alter glutamate and aspartate concentrations at microdialysis time (but based on thimerosal pharmacokinetics, could have been effective soon after its injection). Application of thimerosal to the PFC in perfusion fluid evoked a rapid increase of glutamate overflow. Coadministration of the neurosteroid, dehydroepiandrosterone sulfate (DHEAS; 80 mg/kg; i.p.) prevented the thimerosal effect on glutamate and aspartate; the steroid alone had no influence on these amino acids. Coapplication of DHEAS with thimerosal in perfusion fluid also blocked the acute action of thimerosal on glutamate. In contrast, DHEAS alone reduced overflow of glycine and alanine, somewhat potentiating the thimerosal effect on these amino acids. Since excessive accumulation of extracellular glutamate is linked with excitotoxicity, our data imply that neonatal exposure to thimerosal-containing vaccines might induce excitotoxic brain injuries, leading to neurodevelopmental disorders. DHEAS may partially protect against mercurials-induced neurotoxicity

Long-range temporal correlations in the EEG bursts of human preterm babies.

The electrical activity in the very early human preterm brain, as recorded by scalp EEG, is mostly discontinuous and has bursts of high-frequency oscillatory activity nested within slow-wave depolarisations of high amplitude. The temporal organisation of the occurrence of these EEG bursts has not been previously investigated. We analysed the distribution of the EEG bursts in 11 very preterm (23-30 weeks gestational age) human babies through two estimates of the Hurst exponent. We found long-range temporal correlations (LRTCs) in the occurrence of these EEG bursts demonstrating that even in the very immature human brain, when the cerebral cortical structure is far from fully developed, there is non-trivial temporal structuring of electrical activity

Neonatal NMDA receptor blockade disturbs neuronal migration in rat somatosensory cortex in vivo

Glutamate plays an important role in the control of neuronal migration in the developing cerebral cortex. The present study describes changes in the structure and function of the cerebral cortex after transient blockade of N-methyl-D-aspartate (NMDA) receptors during the late period of neuronal migration. Elvax slices containing the NMDA antagonist MK801 were placed over the somatosensory cortex of newborn rats and the drug was released over a period of 2-3 days. After survival times of 1 or 2 weeks, neuroanatomical and in vitro electrophysiological analyses revealed prominent structural and functional alterations in the cortical region underlying the implant. Cortical lamination was disturbed and heterotopic cell clusters were found in layer I of MK801-treated animals. Morphologically identified pyramidal neurons recorded in MK801-treated cortex revealed late NMDA receptor-mediated synaptic inputs and fragile monosynaptic responses at stimulation frequencies >0.2 Hz. Our data indicate that impairment of NMDA receptors during early corticogenesis induces neuronal migration disorders and delays the functional maturation of the developing cortical network