Chronic exposure to neonicotinoids increases neuronal vulnerability to mitochondrial dysfunction in the bumblebee (Bombus terrestris)

This work was funded jointly by the Biotechnology and Biological Sciences Research Council, the Department for Environment, Food and Rural Affairs, the Natural Environment Research Council, the Scottish Government, and The Wellcome Trust, under the Insect Pollinators Initiative (United Kingdom) Grant BB/ 1000313/1 (to C.N.C.).The global decline in the abundance and diversity of insect pollinators could result from habitat loss, disease, and pesticide exposure. The contribution of the neonicotinoid insecticides (e.g., clothianidin and imidacloprid) to this decline is controversial, and key to understanding their risk is whether the astonishingly low levels found in the nectar and pollen of plants is sufficient to deliver neuroactive levels to their site of action: the bee brain. Here we show that bumblebees (Bombusterrestris audax) fed field levels [10 nM, 2.1 ppb (w/w)] of neonicotinoid accumulate between 4 and 10 nM in their brains within 3 days. Acute (minutes) exposure of cultured neurons to 10 nM clothianidin, but not imidacloprid, causes a nicotinic acetylcholine receptor-dependent rapid mitochondrial depolarization. However, a chronic (2 days) exposure to 1 nM imidacloprid leads to a receptor-dependent increased sensitivity to a normally innocuous level of acetylcholine, which now also causes rapid mitochondrial depolarization in neurons. Finally, colonies exposed to this level of imidacloprid show deficits in colony growth and nest condition compared with untreated colonies. These findings provide a mechanistic explanation for the poor navigation and foraging observed in neonicotinoid treated bumblebee colonies.Publisher PDFPeer reviewe

Terrain Park Injuries

Background: This study examined demographics, injury pattern, and hospital outcome in patients injured in winter resort terrain parks.Methods: The study included patients >12 years of age who presented to a regional trauma center with an acute injury sustained at a winter resort. Emergency department (ED) research assistants collected patient injury and helmet use information using a prospectively designed questionnaire. ED and hospital data were obtained from trauma registry and hospital records.Results: Seventy-two patients were injured in a terrain park, and 263 patients were injured on non-terrain park slopes. Patients injured in terrain parks were more likely to be male [68/72 (94%) vs. 176/263 (67%), p<0.0001], younger in age [23 ± 7 vs. 36 ± 17, p<0.0001], live locally [47/72 (65%) vs. 124/263 (47%), p=0.006], use a snowboard [50/72 (69%) vs. 91/263 (35%), p<0.0001], hold a season pass [46/66 (70%) vs. 98/253 (39%), p<0.0001], and sustain an upper extremity injury [29/72 (40%) vs. 52/263 (20%), p<0.001] when compared to patients injured on non-terrain park slopes. There were no differences between the groups in terms of EMS transport to hospital, helmet use, admission rate, hospital length of stay, and patients requiring specialty consultation in the ED.Conclusions: Patients injured in terrain parks represent a unique demographic within winter resort patrons. Injury severity appears to be similar to those patients injured on non-terrain park slopes.[West J Emerg Med. 2009;10(4):257-262.

Urban Greening in North Carolina: Case Studies from New Bern, Mecklenburg County, and Raleigh

Carolina Planning regularly solicits articles on recent projects from members of the North Carolina chapter of the American Planning Association (NCAPA). This year’s submissions focused on water resource management – an important element of urban greening efforts. From a riverwalk in New Bern – the host city for the 2010 NCAPA Conference – to a stream restoration project in Mecklenburg County and an educational wetlands park in Raleigh, these projects provide valuable insight into the local planning process

Evaluation of recombinant influenza virus-simian immunodeficiency virus vaccines in macaques

There is an urgent need for human immunodeficiency virus (HIV) vaccines that induce robust mucosal immunity. Influenza A viruses (both H1N1 and H3N2) were engineered to express simian immunodeficiency virus (SIV) CD8 T-cell epitopes and evaluated following administration to the respiratory tracts of 11 pigtail macaques. Influenza virus was readily detected from respiratory tract secretions, although the infections were asymptomatic. Animals seroconverted to influenza virus and generated CD8 and CD4 T-cell responses to influenza virus proteins. SIV-specific CD8 T-cell responses bearing the mucosal homing marker 7 integrin were induced by vaccination of naïve animals. Further, SIV-specific CD8 T-cell responses could be boosted by recombinant influenza virus-SIV vaccination of animals with already-established SIV infection. Sequential vaccination with influenza virus-SIV recombinants of different subtypes (H1N1 followed by H3N2 or vice versa) produced only a limited boost in immunity, probably reflecting T-cell immunity to conserved internal proteins of influenza A virus. SIV challenge of macaques vaccinated with an influenza virus expressing a single SIV CD8 T cell resulted in a large anamnestic recall CD8 T-cell response, but immune escape rapidly ensued and there was no impact on chronic SIV viremia. Although our results suggest that influenza virus-HIV vaccines hold promise for the induction of mucosal immunity to HIV, broader antigen cover will be needed to limit cytotoxic T-lymphocyte escape

5-hydroxytryptamine (5-HT) cellular sequestration during chronic exposure delays 5-HT₃ receptor resensitization due to Its subsequent release

The serotonergic synapse is dynamically regulated by serotonin (5-hydroxytryptamine (5-HT)) with elevated levels leading to the down-regulation of the serotonin transporter and a variety of 5-HT receptors, including the 5-HT type-3 (5-HT(3)) receptors. We report that recombinantly expressed 5-HT(3) receptor binding sites are reduced by chronic exposure to 5-HT (IC(50) of 154.0 ± 45.7 μm, t(½) = 28.6 min). This is confirmed for 5-HT(3) receptor-induced contractions in the guinea pig ileum, which are down-regulated after chronic, but not acute, exposure to 5-HT. The loss of receptor function does not involve endocytosis, and surface receptor levels are unaltered. The rate and extent of down-regulation is potentiated by serotonin transporter function (IC(50) of 2.3 ± 1.0 μm, t(½) = 3.4 min). Interestingly, the level of 5-HT uptake correlates with the extent of down-regulation. Using TX-114 extraction, we find that accumulated 5-HT remains soluble and not membrane-bound. This cytoplasmically sequestered 5-HT is readily releasable from both COS-7 cells and the guinea pig ileum. Moreover, the 5-HT level released is sufficient to prevent recovery from receptor desensitization in the guinea pig ileum. Together, these findings suggest the existence of a novel mechanism of down-regulation where the chronic release of sequestered 5-HT prolongs receptor desensitization

The microsporidian parasites Nosema ceranae and Nosema apis are widespread in honeybee (Apis mellifera) colonies across Scotland

Nosema ceranae is spreading into areas where Nosema apis already exists. N. ceranae has been reported to cause an asymptomatic infection that may lead, ultimately, to colony collapse. It is thought that there may be a temperature barrier to its infiltration into countries in colder climates. In this study, 71 colonies from Scottish Beekeeper’s Association members have been screened for the presence of N. apis and N. ceranae across Scotland. We find that only 11 of the 71 colonies tested positive for spores by microscopy. However, 70.4 % of colonies screened by PCR revealed the presence of both N. ceranae and N. apis, with only 4.2 or 7 % having either strain alone and 18.3 % being Nosema free. A range of geographically separated colonies testing positive for N. ceranae were sequenced to confirm their identity. All nine sequences confirmed the presence of N. ceranae and indicated the presence of a single new variant. Furthermore, two of the spore-containing colonies had only N. ceranae present, and these exhibited the presence of smaller spores that could be distinguished from N. apis by the analysis of average spore size. Differential quantification of the PCR product revealed N. ceranae to be the dominant species in all seven samples tested. In conclusion, N. ceranae is widespread in Scotland where it exists in combination with the endemic N. apis. A single variant, identical to that found in France (DQ374655) except for the addition of a single nucleotide polymorphism, is present in Scotland