Astrocyte calcium dysfunction causes early network hyperactivity in Alzheimer's disease

Dysfunctions of network activity and functional connectivity (FC) represent early events in Alzheimer's disease (AD), but the underlying mechanisms remain unclear. Astrocytes regulate local neuronal activity in the healthy brain, but their involvement in early network hyperactivity in AD is unknown. We show increased FC in the human cingulate cortex several years before amyloid deposition. We find the same early cingulate FC disruption and neuronal hyperactivity in AppNL-F mice. Crucially, these network disruptions are accompanied by decreased astrocyte calcium signaling. Recovery of astrocytic calcium activity normalizes neuronal hyperactivity and FC, as well as seizure susceptibility and day/night behavioral disruptions. In conclusion, we show that astrocytes mediate initial features of AD and drive clinically relevant phenotypes

Hymenoptera of Canada

A summary of the numbers of species of the 83 families of Hymenoptera recorded in Canada is provided. In total, 8757 described species are recorded compared to approximately 6000 in 1979, which is a 46% increase. Of the families recognized in 1979, three have been newly recorded to Canada since the previous survey: Anaxyelidae (Anaxyleoidea), Liopteridae (Cynipoidea), and Mymarommatidae (Mymarommatoidea). More than 18,400 BINs of Canadian Hymenoptera are available in the Barcode of Life Data Systems (Ratnasingham and Hebert 2007) implying that nearly 9650 undescribed or unrecorded species of Hymenoptera may be present in Canada (and more than 10,300 when taking into account additional species that have not been DNA barcoded). The estimated number of unrecorded species is very similar to that of 1979 (10,637 species), but the percentage of the fauna described/recorded has increased from 36% in 1979 to approximately 45% in 2018. Summaries of the state of knowledge of the major groups of Hymenoptera are presented, including brief comments on numbers of species, biology, changes in classification since 1979, and relevant taxonomic references

Les Episyron des Iles Philippines (Hymenoptera: Pompilidae, Pompilinae)

SUMMARY The author investigates the species of the genus Episyron Schioedte occurring in the Philippines. Six species, instead of eight originally recorded, are revised. Two lectotypes (E. vagabundum Smith, 1858 and Anoplius lepidohirtus Turner, 1910) are designated; five specific synonyms are newly established (E. saussurei Banks, 1934 = E. binghami Banks, 1934; Pompilus cognatus Smith, 1865 and Anoplius lepidohirtus Turner, 1910 = E. pilifrons Smith, 1859; Pompilus capitosus Smith, 1879 = E. vagabundum Smith, 1858; E. smithi Banks, 1934 = Paracyphononyx incognitus Cameron, 1891). Three new combinations are established (Pompilus cognatus Smith, 1864 = E. cognatus and Pompilus capitosus Smith, 1879 = E. capitosus; E. smithi Banks, 1934 = Paracyphononyx smithi). Distributional and biological data are given and a key to species ( ♀ only) provided. Dans une courte note (1938: 40) consacrée aux Pompilides de Singapore ainsi que dans un travail plus important sur ceux des Iles Philippines (1934), Nathan Banks a réservé plusieurs pages à l'étude du genre Episyron Schioedte, y décrivant notamment un certain nombre d'espèces nouvelles. Le catalogue des Hyménoptères des Iles Philippines de Baltazar (1966) présente une liste des espèces du genre absolument conforme à celle que l'on peut tirer des travaux de Banks. Grâce à l'assistance de MM. les Dr. A. S. Menke et Κ. V. Krombein (National Museum of Natural History, Washington (USNM)) et de Ms. Marilyn M. Pearce (Museum of Comparative Zoology Cambridge (MCZ)), j'ai eu récemment l'opportunité d'étudier les matériaux, y compris les types, examinés autrefois par Banks ainsi qu'un certain nombre de spécimens de même origine, cédés en échange à d'autres institutions: Rijksmuseum va

Fauna Europaea: Hymenoptera - Apocrita (excl. Ichneumonoidea)

Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Hymenoptera is one of the four largest orders of insects, with about 130,000 described species. In the Fauna Europaea database, ‘Hymenoptera - Apocrita (excluding Ichneumonoidea)’ comprises 13 superfamilies, 52 families, 91 subfamilies, 38 tribes and 13,211 species. The paper includes a complete list of taxa dealt with, the number of species in each and the name of the specialist responsible for data acquisition. As a general conclusion about the European fauna of Hymenoptera, the best known countries in terms of recorded species are those from northwestern Europe, with the least known fauna probably in the more eastern and southeastern parts of Europe