Microtubule-associated protein tau is essential for long-term depression in the hippocampus

The microtubule-associated protein tau is a principal component of neurofibrillary tangles, and has been identified as a key molecule in Alzheimer's disease and other tauopathies. However, it is unknown how a protein that is primarily located in axons is involved in a disease that is believed to have a synaptic origin. To investigate a possible synaptic function of tau, we studied synaptic plasticity in the hippocampus and found a selective deficit in long-term depression (LTD) in tau knockout mice in vivo and in vitro, an effect that was replicated by RNAi knockdown of tau in vitro. We found that the induction of LTD is associated with the glycogen synthase kinase-3-mediated phosphorylation of tau. These observations demonstrate that tau has a critical physiological function in LTD.A.T. was supported by the research funding for longevity sciences (23-39) from National Center for Geriatrics and Gerontology, and the Strategic Research Programme for Brain Science ('Integrated Research on Neuropsychiatric Disorders') and Grant in Aid for Scientific Research on Innovative Areas ('Brain Environment') from the Ministry of Education, Science, Sports and Culture of Japan. K.C., D.J.W. and G.L.C. were supported by UK Wellcome Trust-MRC Neurodegenerative Disease Initiative Programme. K.C. was supported by the Korea-UK Alzheimer's Disease Research Consortium programme from the Ministry of Health and Welfare (Korea). G.L.C. was supported by the WCU Programme (Korea). I.S. was supported by the British Council. The collaboration between K.C. and A.T. was supported by a Sasakawa Foundation grant awarded to K.C. K.C. was supported by the Wolfson Research Merit Award and the Royal Society, London

Intracellular oligomeric amyloid-beta rapidly regulates GluA1 subunit of AMPA receptor in the hippocampus

The acute neurotoxicity of oligomeric forms of amyloid-beta 1-42 (Abeta) is implicated in the pathogenesis of Alzheimer's disease (AD). However, how these oligomers might first impair neuronal function at the onset of pathology is poorly understood. Here we have examined the underlying toxic effects caused by an increase in levels of intracellular Abeta, an event that could be important during the early stages of the disease. We show that oligomerised Abeta induces a rapid enhancement of AMPA receptor-mediated synaptic transmission (EPSCA) when applied intracellularly. This effect is dependent on postsynaptic Ca(2+) and PKA. Knockdown of GluA1, but not GluA2, prevents the effect, as does expression of a S845-phosphomutant of GluA1. Significantly, an inhibitor of Ca(2+)-permeable AMPARs (CP-AMPARs), IEM 1460, reverses the increase in the amplitude of EPSCA. These results suggest that a primary neuronal response to intracellular Abeta oligomers is the rapid synaptic insertion of CP-AMPARs

Intracellular oligomeric amyloid-beta rapidly regulates GluA1 subunit of AMPA receptor in the hippocampus

The acute neurotoxicity of oligomeric forms of amyloid-beta 1-42 (A beta) is implicated in the pathogenesis of Alzheimer's disease (AD). However, how these oligomers might first impair neuronal function at the onset of pathology is poorly understood. Here we have examined the underlying toxic effects caused by an increase in levels of intracellular A beta, an event that could be important during the early stages of the disease. We show that oligomerised A beta induces a rapid enhancement of AMPA receptor-mediated synaptic transmission (EPSCA) when applied intracellularly. This effect is dependent on postsynaptic Ca2+ and PKA. Knockdown of GluA1, but not GluA2, prevents the effect, as does expression of a S8(45)-phosphomutant of GluA1. Significantly, an inhibitor of Ca2+-permeable AMPARs (CP-AMPARs), IEM 1460, reverses the increase in the amplitude of EPSCA. These results suggest that a primary neuronal response to intracellular A beta oligomers is the rapid synaptic insertion of CP-AMPARs114161sciescopu

Rabbits, stoats and the predator problem: Why a strong animal rights position need not call for human intervention to protect prey from predators

Animal rights positions face the ‘predator problem’: the suggestion that if the rights of nonhuman animals are to be protected, then we are obliged to interfere in natural ecosystems to protect prey from predators. Generally, rather than embracing this conclusion, animal ethicists have rejected it, basing this objection on a number of different arguments. This paper considers but challenges three such arguments, before defending a fourth possibility. Rejected are Peter Singer’s suggestion that interference will lead to more harm than good, Sue Donaldson and Will Kymlicka’s suggestion that respect for nonhuman sovereignty necessitates non-interference in normal circumstances, and Alasdair Cochrane’s solution based on the claim that predators cannot survive without killing prey. The possibility defended builds upon Tom Regan’s suggestion that predators, as moral patients but not moral agents, cannot violate the rights of their prey, and so the rights of the prey, while they do exist, do not call for intervention. This idea is developed by a consideration of how moral agents can be more or less responsible for a given event, and defended against criticisms offered by thinkers including Alasdair Cochrane and Dale Jamieson

Crop Updates 2008 - Lupins, Pulses and Oilseeds

This session covers twenty six papers from different authors: Regional Roundup 1. SOUTH EAST AGRICULTURAL REGION, Mark Seymour Department of Agriculture and Food, and Robert Johnson CBH Group, Esperance 2. CENTRAL AGRICULTURAL REGION, Ian Pritchard, Department of Agriculture and Food 3. GREAT SOUTHERN AND LAKES REGION, Raj Malik, Department of Agriculture and Food 4. NORTHERN AGRICULTURAL REGION, Wayne Parker and Martin Harries, Department of Agriculture and Food LUPINS 5. Cropping lupins in wide rows in Western Australia, Martin Harries and Bob French, Department of Agriculture and Food 6. The effect of sowing time and radish density on lupin yield, Martin Harries and Jo Walker, Department of Agriculture and Food 7. Lupin agronomy affects crop competitiveness with annual ryegrass, Bob French and Laurie Maiolo, Department of Agriculture and Food 8. Identification of lupin mutants with tolerance to isoxaflutole, Leigh Smith, Department of Agriculture and Food PULSES 9. Chickpea 2007 Crop Variety Testing (CVT) and National Variety Testing (NVT), Alan Harris, Rod Hunter, Tanveer Khan and Jenny Garlinge, Department of Agriculture and Food 10. Desi chickpea breeding: Evaluation of advanced lines, Tanveer Khan1, Poran Gaur2, Kadambot Siddique3, Heather Clarke4, Neil Turner4, William MacLeod4, Stuart Morgan1, Alan Harris1, 1Department of Agriculture and Food, 2International Crop Research Institute for the Semi Arid Tropics (ICRISAT); 3The University of Western Australia; 4Centre for Legumes in Mediterranean Agriculture 11. Can wide rows buffer chickpea growth against dry environments? Bob French and Wendy Vance, Department of Agriculture and Food, and School of Environmental Sciences, Murdoch University 12. Field pea 2007 Crop Variety Testing (CVT) and National Variety Testing (NVT), Alan Harris, Rod Hunter, Tanveer Khan and Jenny Garlinge, Department of Agriculture and Food 13. Australian Field Pea improvement Program (AFPIP): Evaluation of advanced breeding lines, Tanveer Khan1, Phillip Chambers1, Chris Veitch1, Stuart Morgan1, Alan Harris1, and Tony Leonforte 2, 1Department of Agriculture and Food, 2Department of Primary Industries, Victoria 14. Ability of semi-leafless field peas to recover after rolling, Mark Seymour and Rodger Beermier, Department of Agriculture and Food 15. Field pea germplasm enhancement for black spot resistance, Tanveer Khan, Stuart Morgan, Alan Harris and Phillip Chambers, Department of Agriculture and Food 16. Application of ‘Blackspot Manager’ model to identifying a low risk sowing date for field pea in South Australia and Western Australia in 2007, Moin Salam1, Jenny Davidson2, Jean Galloway1, Pip Payne2, Tess Humphries2, Bill MacLeod1 and Art Diggle1, 1Department of Agriculture and Food, 2SARDI, South Australia 17. Late post emergent herbicide sprays for field pea, Mark Seymour and Rodger Beermier, Department of Agriculture and Food 18. Adding triasulfuron to croptopping mixes does not affect the yield of field pea, Mark Seymour, Department of Agriculture and Food 18. Herbicide tolerance of field pea varieties, Harmohinder Dhammu and Mark Seymour, Department of Agriculture and Food 19. Breeding highlights of the PBA lentil program, Michael Materne1, Kerry Regan2, Chris Veitch2 and Phil Chambers2, 1Department of Primary Industries, Victoria 2Department of Agriculture and Food CANOLA 20. How late can I sow canola in 2008? Mohammad Amjad, Andy Sutherland and Pat Fels, Department of Agriculture and Food 21. Direct harvesting canola, Glen Riethmuller1, Wallace Cowling2, Milton Sanders2, Eliot Jones2 and Chris Newman1, 1Department of Agriculture and Food, Western Australia, 2Canola Breeders Western Australia Pty Ltd 22. Agronomic performance of new hybrid canola and juncea canola in low, medium and high rainfall environments of Western Australia, Mohammad Amjad, Andy Sutherland and Pat Fels, Department of Agriculture and Food 23. Comparative performance of new canola varieties in commercial-scale field trials of Oilseeds WA – 2007, Mohammad Amjad1, John Duff2 and David Sermon3 1Department of Agriculture and Food, 2Oilseeds Western Australia and John Duff & Associates, Perth; 3ConsultAg, Perth 24. The effect of rotation crops, trash retention and prophylactic sprays on arthropod abundance in a following canola crop, Svetlana Micic, Anthony Dore and Geoff Strickland, Department of Agriculture and Food OATS 25. Fungicide options for controlling disease in oats, Raj Malik and Blakely Paynter, Department of Agriculture and Food 26. Herbicide tolerance of new oat varieties, Harmohinder Dhammu, Vince Lambert and Chris Roberts, Department of Agriculture and Foo