Individual variation in orientation promotes a 3000‐km latitudinal change in wintering grounds in a long‐distance migratory raptor

Migrating juvenile birds rely on endogenous information in choosing the direction in which to fly, but such input may be overridden by social interactions with experienced individuals. We tagged seven juvenile Short‐toed Eagles Circaetus gallicus with GPS transmitters in southern Italy. This trans‐Saharan migrant flies mainly by soaring and is therefore not well adapted to performing long water crossings. Five of the seven tagged juveniles used the longer but apparently safer route towards the Strait of Gibraltar, and two migrated along a southerly trajectory and subsequently spent the winter in Sicily, apparently forced to do so by the 150‐km‐wide Sicily Channel. One of these individuals took the longer route the following autumn. These results, combined with long‐term (15 years) visual field observations involving thousands of individuals, suggest that inexperienced Short‐toed Eagles may learn their migratory routes from experienced adults, whereas some of them migrate south in response to an innate orientation instinct. Transport costs, inherited information and geography apparently interact, forcing some Short‐toed Eagles to winter 3000 km to the north of the majority of their conspecifics.     

First report of Thelazia callipaeda (Spirurida, Thelaziidae) in wolves in Italy

Thelazia callipaeda (Spirurida, Thelaziidae) infects the eyes of humans and rabbits as well of domestic and wild carnivores (i.e., dogs, cats, and foxes). The first three cases of infection by T. callipaeda eyeworms in wolves (Canis lupus) are here described with up to 96 nematodes collected from a single animal. The host competence of wolf was demonstrated by the retrieval of adult worms in the eyes of all examined animals. All nematodes collected were evaluated by morphologic and molecular techniques. Sequence analysis of the partial mitochondrial cytochrome c oxidase subunit 1 gene (cox1) confirmed that only one haplotype of T. callipaeda was present. The competence of wolves as a definitive host for T. callipaeda is discussed in view of the relevance of wild fauna in maintaining and spreading eyeworm infection in humans and domestic animals.     

Glutamate triggers intracellular Ca2+ oscillations and nitric oxide release by inducing NAADP- and InsP3-dependent Ca2+ release in mouse brain endothelial cells

The neurotransmitter glutamate increases cerebral blood flow by activating postsynaptic neurons and presynaptic glial cells within the neurovascular unit. Glutamate does so by causing an increase in intracellular Ca²⁺ concentration ([Ca²⁺]_i) in the target cells, which activates the Ca²⁺/Calmodulin-dependent nitric oxide (NO) synthase to release NO. It is unclear whether brain endothelial cells also sense glutamate through an elevation in [Ca²⁺]_i and NO production. The current study assessed whether and how glutamate drives Ca²⁺-dependent NO release in bEND5 cells, an established model of brain endothelial cells. We found that glutamate induced a dose-dependent oscillatory increase in [Ca²⁺]_i, which was maximally activated at 200 μM and inhibited by α-methyl-4-carboxyphenylglycine, a selective blocker of Group 1 metabotropic glutamate receptors. Glutamate-induced intracellular Ca²⁺ oscillations were triggered by rhythmic endogenous Ca²⁺ mobilization and maintained over time by extracellular Ca²⁺ entry. Pharmacological manipulation revealed that glutamate-induced endogenous Ca²⁺ release was mediated by InsP₃-sensitive receptors and nicotinic acid adenine dinucleotide phosphate (NAADP) gated two-pore channel 1. Constitutive store-operated Ca²⁺ entry mediated Ca²⁺ entry during ongoing Ca²⁺ oscillations. Finally, glutamate evoked a robust, although delayed increase in NO levels, which was blocked by pharmacologically inhibition of the accompanying intracellular Ca²⁺ signals. Of note, glutamate induced Ca²⁺-dependent NO release also in hCMEC/D3 cells, an established model of human brain microvascular endothelial cells. This investigation demonstrates for the first time that metabotropic glutamate-induced intracellular Ca²⁺ oscillations and NO release have the potential to impact on neurovascular coupling in the brain.     

Preparation, properties and metabolism of retro-3-dehydroretinyl acetate

1. Treatment of 3-dehydroretinyl acetate with aqueous hydrobromic acid resulted in the formation of retro-3-dehydroretinyl acetate, which, on alkaline hydrolysis, gave the corresponding alcohol. 2. retro-3-Dehydroretinyl acetate was isomerized to 3-dehydrovitamin A when fed to vitamin A-deficient rats. 3. When retro-3-dehydroretinyl acetate was administered orally, it was hydrolysed to retro-3-dehydroretinol in the rat intestine, isomerized to 3-dehydroretinol and esterified before being transported to the liver for storage. 4. When administered intraperitoneally, both 3-dehydrovitamin A and retro-3-dehydrovitamin A were accumulated in liver and other tissues, whereas after enterectomy 3-dehydrovitamin A was not detected anywhere in the body. 5. The small intestine was shown to be the major site of conversion of retro-3-dehydrovitamin A into 3-dehydrovitamin A. 6. The extent of conversion of retro-3-dehydroretinyl acetate into 3-dehydrovitamin A was much smaller than that of the conversion of retro-retinyl acetate into vitamin A. 7. The biological potency of retro-3-dehydroretinyl acetate, determined by the rat-growth assay, was 2.6% of that all-trans-retinyl acetate, when given orally.     

Event-driven simulation of cerebellar granule cells

Around half of the neurons of a human brain are granule cells (approximately 10(11)granule neurons) [Kandel, E.R., Schwartz, J.H., Jessell, T.M., 2000. Principles of Neural Science. McGraw-Hill Professional Publishing, New York]. In order to study in detail the functional role of the intrinsic features of this cell we have developed a pre-compiled behavioural model based on the simplified granule-cell model of Bezzi et al. [Bezzi, M., Nieus, T., Arleo, A., D'Angelo, E., Coenen, O.J.-M.D., 2004. Information transfer at the mossy fiber-granule cell synapse of the cerebellum. 34th Annual Meeting. Society for Neuroscience, San Diego, CA, USA]. We can use an efficient event-driven simulation scheme based on lookup tables (EDLUT) [Ros, E., Carrillo, R.R., Ortigosa, E.M., Barbour, B., Ags, R., 2006. Event-driven simulation scheme for spiking neural networks using lookup tables to characterize neuronal dynamics. Neural Computation 18 (12), 2959-2993]. For this purpose it is necessary to compile into tables the data obtained through a massive numerical calculation of the simplified cell model. This allows network simulations requiring minimal numerical calculation. There are three major features that are considered functionally relevant in the simplified granule cell model: bursting, subthreshold oscillations and resonance. In this work we describe how the cell model is compiled into tables keeping these key properties of the neuron model.     

Triacsin C inhibits the formation of 1H NMR-visible mobile lipids and lipid bodies in HuT 78 apoptotic cells

Nuclear magnetic resonance-visible mobile lipids (ML) have been reported to accumulate during cell apoptosis in vitro and in vivo. The biogenesis, biochemical nature and structure of these lipids are still under debate. In this study, a human lymphoblastoid cell line, HuT 78, was induced to apoptosis by exposure to anti-Fas monoclonal antibodies (alpha-Fas mAb) followed by incubation for different time intervals (1-24 h, hypodiploid cell fraction, H, varying from 1% to over 60%) either in the presence or in the absence of 5.0 microM Triacsin C (TRC), specific inhibitor of long-chain acyl-CoA synthetase (ACS). The increase of ML in apoptotic cells correlated linearly with H and was associated with: (a) accumulation of intracellular lipid bodies, detected by confocal laser scanning microscopy in lipophilic dye-stained cells; (b) increases, detected by thin-layer chromatography in total lipid extracts, in the relative abundance of triacylglycerides (TAG) and cholesteryl esters (CE), with corresponding decreases of phospholipids (PL). TRC completely abolished both ML and lipid body formation in anti-Fas-treated apoptotic cells, with concomitant reversion of TAG, CE and PL to control levels, but did not alter cell viability nor did it inhibit apoptosis. ML signals detected during anti-Fas-induced apoptosis therefore appear to originate from neutral lipids assembled in intracellular lipid bodies, synthesised from cellular acyl-CoA pools.     

A high-affinity reversible protein stain for Western blots

We describe a reversible staining technique, using MemCode, a reversible protein stain by which proteins can be visualized on nitrocellulose and polyvinylidine fluoride (PVDF) membranes without being permanently fixed to the membrane itself. This allows subsequent immunoblot analysis of the proteins to be performed. The procedure is applicable only to protein blots on nitrocellulose and PVDF membranes. MemCode is a reversible protein stain composed of copper as a part of an organic complex that interacts noncovalently with proteins. MemCode shows rapid protein staining, taking 30s to 1 min for completion. The method is simple and utilizes convenient application conditions that are compatible with the matrix materials and the protein. The stain is more sensitive than any previously described dye-based universal protein staining system. The turquoise-blue-stained protein bands do not fade with time and are easy to photograph compared to those stained with Ponceau S. Absorbance in the blue region of the spectrum offers good properties for photo documentation and avoids interference from common biological chromophores. The stain on the protein is easily reversible in 2 min for nitrocellulose membrane and in 10 min for PVDF membrane with MemCode stain eraser. The stain is compatible with general Western blot detection systems, and membrane treatment with MemCode stain does not interfere with conventional chemiluminescent or chromogenic detection using horseradish peroxide and alkaline phosphatase substrates. The stain is also compatible with N-terminal sequence analysis of proteins.