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Tick-borne encephalitis virus (TBEV) is found in Ixodes ricinus ticks throughout the area where viable tick populations exist. In Norway, TBEV is found in I. ricinus from the south coast until Brønnøy municipality in Nordland County and the range of the vector is expanding due to changes in climate, vegetation, host animals and environmental conditions. TBEV might thus have the potential to establish in new areas when I. ricinus expand its geographical distribution. At present, there is little knowledge on the status of the virus in high-altitude areas of inland regions in Norway. It has previously been indicated that reindeer may be an important sentinel species and indicator of the spread of ticks and TBEV in high-altitude regions. In this study, 408 semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) from eight herds, from Tana in Troms and Finnmark County in northern Norway to Filefjell in Innlandet and Viken Counties in southern Norway, were screened for TBEV antibodies using a commercial enzyme-linked immunosorbent assay (ELISA). We found 16 TBEV reactive reindeer samples by ELISA; however, these results could not be confirmed by the serum neutralization test (SNT). This could indicate that a flavivirusand not necessarily TBEV, may be circulating among Norwegian semi-domesticated reindeer. The results also indicate that TBEV was not enzootic in Norwegian semi-domesticated reindeer in 2013–2015. This knowledge is important as an information base for future TBEV and flavivirus surveillance in Norway.

The tick-borne encephalitis virus (TBEV), a zoonotic flaviviral infection, is endemic in large parts of Norway and Eurasia. Humans are mainly infected with TBEV via bites from infected ticks. In Norway, the main geographical distribution of ticks is along the Norwegian coastline from southeast (~59°N) and up to the southern parts of Nordland County (~65°N). In this study, we collected ticks by flagging along the coast from Østfold County to Nordland County. By whole-genome sequencing of the mitochondrial genome of Ixodes ricinus, the phylogenetic tree suggests that there is limited phylogeographic structure both in Norway and in Europe. The overall TBEV prevalence is 0.3% for nymphs and 4.3% for adults. The highest estimated TBEV prevalence in adult ticks was detected in Rogaland and Vestfold County, while for nymphs it is highest in Vestfold, Vest-Agder and Rogaland. The present work is one of the largest studies on distribution and prevalence of TBEV in ticks in Scandinavia, showing that the virus is wider distributed in Norway than previously anticipated.

Tick-borne encephalitis virus (TBEV) is recognized as the most important zoonotic tick-transmitted virus in Europe. TBEV is mainly transmitted to humans through bites from TBEV-infected ticks (Ixodes ricinus and Ixodes persulcatus). However, alimentary infection after consumption of unpasteurized milk and cheese from domestic ruminants has been reported. There is little information about TBEV in ruminants in Norway. The objectives of this study were to analyse unpasteurized cow milk for TBEV RNA and to study the presence of IgG antibodies to TBEV in the same animals. A total of 112 milk and blood samples were collected from cows from five different farms spread from southern to northern Norway. The milk samples were analysed by an in-house reverse transcription (RT) real-time polymerase chain reaction and confirmed by pyrosequencing. Serum samples were screened by a commercial enzyme-linked immunosorbent assay and verified by a TBEV-specific serum neutralization test. We found TBEV RNA in unpasteurized milk collected from farms in the municipalities of Mandal, Skedsmo and Brønnøy in 5.4% of the tested animals. Specific antibodies to TBEV were only detected in Arendal, where 88.2% of the tested animals were positive. Further studies on milk containing TBEV RNA should be performed to conclude if TBEV found in unpasteurized milk in Norway is infectious, which could be of great importance in a One Health perspective.

The membrane potential changes following action potentials in thin unmyelinated cortical axons with en passant boutons may be important for synaptic release and conduction abilities of such axons. In the lack of intra-axonal recording techniques we have used extracellular excitability testing as an indirect measure of the after-potentials. We recorded from individual CA3 soma in hippocampal slices and activated the axon with a range of stimulus intensities. When conditioning and test stimuli were given to the same site the excitability changes were partly masked by local effects of the stimulating electrode at intervals 1 Hz, a condition that activates a hyperpolarization-activated current (Ih) in these axons, the decay was faster than at lower stimulation rates. This effect was reduced by the Ih blocker ZD7288. These data suggest that the decay time course of the action potential-induced hyperexcitability is determined by the membrane time constant.

The mammalian cortex is densely populated by extensively branching, thin, unmyelinated axons that form en passant synapses. Some thin axons in the peripheral nervous system hyperpolarize if action potential frequency exceeds 1-5 Hz. To test the hypothesis that cortical axons also show activity-induced hyperpolarization, we recorded extracellularly from individual CA3 pyramidal neurons while activating their axon with trains consisting of 30 electrical stimuli. Synaptic excitation was blocked by kynurenic acid. We observed a positive correlation between stimulation strength and the number of consecutive axonal stimuli that resulted in soma spikes, suggesting that the threshold increased as a function of the number of spikes. During trains without response failures there was always a cumulative increase in the soma response latency. Intermittent failures, however, decreased the latency of the subsequent response. At frequencies of1 Hz, the threshold and latency increases were enhanced by blocking the hyperpolarization-activated H current (Ih)by applying the specific Ih blocker ZD7288 (25 microM) or 2 mM Cs+. Under these conditions, response failures occurred after 15-25 stimuli, independent of the stimulation strength. Adding GABA receptor blockers (saclofen and bicuculline) and a blocker of metabotropic glutamate receptors did not change the activity-induced latency increase in recordings of the compound action potential. We interpret these results as an activity-induced hyperpolarization that is partly counteracted by Ih. Such a hyperpolarization may influence transmitter release and the conduction reliability of these axons.

Relatively few physiological studies have been carried out on intrahippocampal axons. We have recorded compound potentials from fiber groups and the activity of individual axons at 22-25 degrees C to characterize the conduction in subsets of the broad fan-shaped CA3 pyramidal axonal tree, including the Schaffer collaterals and longitudinal branches. The same wide axonal branching was indicated by antidromic activation of individual CA3 pyramidal cells. The average compound action potential latency from the CA3 to the CA1 area (Schaffer collaterals) increased by 4.16 +/- 0.06 ms/mm separation between the stimulation and registration electrodes. The impulses spread 31% faster in the 45-degree oblique temporal than in the transverse direction across CA1. The latency of the longitudinal axons in the CA3 area increased by 6.19 +/- 0.19 ms/mm. More impressive than these direction-dependent differences in latency were the large differences between individual axons running in the same direction. For both the longitudinal axons and the Schaffer collaterals, there was a broad distribution of antidromic latencies for a given distance between the stimulation and recording points. Typically, the fastest impulses arrived in half the time of the slowest. The distribution of compound action potential latencies between two points in the tissue could be made narrower by surgical restriction of the thickness and width of the preparation. By comparison, the cerebellar parallel fibers showed a narrower distribution of their latencies than the Schaffer collaterals. Because the cerebellar fibers run more straight than Schaffer collaterals, this suggested that some of the latency differences of the latter were due to differences in the path length of the axons. One consequence of our findings is that synchronous firing of neighboring CA3 pyramidal cells does not necessarily give synchronous inputs to common target CA1 neurons.

In the Einstein-Carten theory only the traceless part of the torsion field can be related spin. Here we generalize the Einstein-Cartan theory by allowing iutrinsic dilation currents, which couple algebraically to the torsion trace. This implies implies a variable gravitational coupling, G.

The effect of an inflaton scalar field on cosmic rotation is discussed. It is shown that any physically reasonable inflaton scalar will dilute the cosmic vorticity by a factor of R−3γ when the false vacuum decays into matter. Since vorticity decays during inflation as R3γ-5, this leads to a total decay by a factor of R5, which is not dependent on the equation of state of the rotating non-vacuum component of the energy-momentum tensor. Die Inflation und das Rotationsproblem Der Effekt eines inflationierenden Skalarfeldes auf die kosmische Rotation wird diskutiert. Es wird gezeigt, das jeder physikalisch sinnvolle Skalar dieser Art die kosmische Wirbelstarke um den Faktor R−3γ verdunnt. Da die Wirbelstarke infolge der Inflation wie R3γ-5 abnimmt, fuhrt das zu einer totalen Verminderung um den Faktor R−5, was nicht von der Zustandsgleichung der rotierenden Nichtvakuumkomponente des Energie-Impulstensors abhangt.