61 research outputs found

    New genus and species of Pompilinae spider wasps from the Oriental Region (Hymenoptera, Pompilidae)

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    peer reviewedThe new genus Erythropompilus Shimizu & Pitts, gen. nov. from the Oriental Region (Pompilidae, Pompilinae) is described, based on the new species E. malaysiensis Pitts & Shimizu, sp. nov. from Malaysia. Two other new species of this genus, E. thailandensis Pitts & Shimizu, sp. nov. from Thailand and E. taiwanensis Pitts & Shimizu, sp. nov. from Taiwan, are also described. A key to the species is provided, and the taxonomic position of the genus is discussed

    Identification of region-specific astrocyte subtypes at single cell resolution

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    Astrocytes, a major cell type found throughout the central nervous system, have general roles in the modulation of synapse formation and synaptic transmission, blood-brain barrier formation, and regulation of blood flow, as well as metabolic support of other brain resident cells. Crucially, emerging evidence shows specific adaptations and astrocyte-encoded functions in regions, such as the spinal cord and cerebellum. To investigate the true extent of astrocyte molecular diversity across forebrain regions, we used single-cell RNA sequencing. Our analysis identifies five transcriptomically distinct astrocyte subtypes in adult mouse cortex and hippocampus. Validation of our data in situ reveals distinct spatial positioning of defined subtypes, reflecting the distribution of morphologically and physiologically distinct astrocyte populations. Our findings are evidence for specialized astrocyte subtypes between and within brain regions. The data are available through an online database (https://holt-sc.glialab.org/), providing a resource on which to base explorations of local astrocyte diversity and function in the brain.status: publishe

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

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    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

    AAV-mediated delivery of an anti-BACE1 VHH alleviates pathology in an Alzheimer's disease model

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    Single domain antibodies (VHHs) are potentially disruptive therapeutics, with important biological value for treatment of several diseases, including neurological disorders. However, VHHs have not been widely used in the central nervous system (CNS), largely because of their restricted blood–brain barrier (BBB) penetration. Here, we propose a gene transfer strategy based on BBB-crossing adeno-associated virus (AAV)-based vectors to deliver VHH directly into the CNS. As a proof-of-concept, we explored the potential of AAV-delivered VHH to inhibit BACE1, a well-characterized target in Alzheimer’s disease. First, we generated a panel of VHHs targeting BACE1, one of which, VHH-B9, shows high selectivity for BACE1 and efficacy in lowering BACE1 activity in vitro. We further demonstrate that a single systemic dose of AAV-VHH-B9 produces positive long-term (12 months plus) effects on amyloid load, neuroinflammation, synaptic function, and cognitive performance, in the AppNL-G-F Alzheimer’s mouse model. These results constitute a novel therapeutic approach for neurodegenerative diseases, which is applicable to a range of CNS disease targets

    Epidemiological survey of equine influenza in Andalusia, Spain

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    Equine influenza is a highly contagious respiratory disease considered the most important respiratory disease in equids. Although influenza A virus (IAV) has caused outbreaks in equids worldwide, surveillance on these species in Spain has not been conducted. A cross-sectional study was carried out to determine the individual and herd prevalence of antibodies against H3N8 and H7N7 IAV in equids in Andalusia (southern Spain). Antibody against IAV was measured by the single radial haemolysis assay. A spatial scan statistical analysis was carried out using a Bernoulli model. Risk factors associated with IAV infection were assessed by multivariate analysis. Antibodies to H3N8 IAV were detected in 241 out of 464 unvaccinated equids (51.9%; 95% CI: 47.4–56.5). Seropositivity against the H7N7 subtype IAV was not found in any of the analysed animals. Significantly higher seropositivity was found in geriatric (OR= 6.1, P = 0.008, 95% CI= 1.6 – 23.1) and adult (OR= 4.8, P < 0.001, 95% CI= 2.5 – 9.0) equids compared to young. Specific antibodies against A/equine/Shropshire/2010 (H3N8) or A/equine/Newmarket/5/2003 (H3N8) only were confirmed in 11 and 45 of the animals, respectively. The spatial analysis showed a statistically significant cluster centred in the west part of Andalusia. The results confirmed widespread H3N8 subtype IAV exposure in equine species in Andalusia. Conversely, the absence of seropositivity against H7N7 IAV obtained in the present study suggests that this subtype has not circulated in southern Spain in recent years. Because of the animal health and economic consequences of IAV in equids, further surveillance and molecular studies are required to monitor and characterize the most prevalent IAV circulating in these species in Spain

    Hymenoptera of Canada

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    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

    Sur quelques Pompilides orientaux décrits par J. Pérez (1905) et conservés au Muséum national d'Histoire naturelle (Paris) (Hymenoptera, Pompilidae)

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    Some oriental Pompilids described by J. Perez (1905) and conserved in the Muséum national d'Histoire naturelle, Paris. The revision of japanese Pompilidae described by Pérez in 1905 leads to confirm or explicit the identity of seven species of the genera Priocnemis, Auplopus, Dipogon, Anoplius and Aporus. A lectotype is designated for Pompilus unicinctus Pérez and six species are synonymised.La révision des types de Pompilides du Japon décrits par Pérez en 1 905 (Muséum de Paris) permet de confirmer ou de préciser l'identité de sept espèces appartenant aux genres Priocnemis, Auplopus, Dipogon, Anoplius et Aporus. Un lectotype est désigné pour Pompilus unicinctus Pérez et six espèces sont mises en synonymie.Wahis Raymond. Sur quelques Pompilides orientaux décrits par J. Pérez (1905) et conservés au Muséum national d'Histoire naturelle (Paris) (Hymenoptera, Pompilidae). In: Bulletin de la Société entomologique de France, volume 106 (2), juin 2001. pp. 155-160

    Sur quelques Pompilides orientaux décrits par J. Pérez (1905) et conservés au Muséum national d'Histoire naturelle (Paris) (Hymenoptera, Pompilidae)

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    Some oriental Pompilids described by J. Perez (1905) and conserved in the Muséum national d'Histoire naturelle, Paris. The revision of japanese Pompilidae described by Pérez in 1905 leads to confirm or explicit the identity of seven species of the genera Priocnemis, Auplopus, Dipogon, Anoplius and Aporus. A lectotype is designated for Pompilus unicinctus Pérez and six species are synonymised.La révision des types de Pompilides du Japon décrits par Pérez en 1 905 (Muséum de Paris) permet de confirmer ou de préciser l'identité de sept espèces appartenant aux genres Priocnemis, Auplopus, Dipogon, Anoplius et Aporus. Un lectotype est désigné pour Pompilus unicinctus Pérez et six espèces sont mises en synonymie.Wahis Raymond. Sur quelques Pompilides orientaux décrits par J. Pérez (1905) et conservés au Muséum national d'Histoire naturelle (Paris) (Hymenoptera, Pompilidae). In: Bulletin de la Société entomologique de France, volume 106 (2), juin 2001. pp. 155-160

    Study of the mechanisms of action of oxytocin in the modulation of astro-neuronal circuits of pain modulation

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    La douleur est un phénomène complexe régi par le système nerveux. De nombreuses molécules modulent la douleur par des mécanismes complexes et variés. L’une d’elle, l’ocytocine, est plus connue pour ses rôles dans la reproduction et les interactions sociales, mais est pourtant un puissant agent analgésique endogène. Au cours de cette thèse, j’ai cherché à comprendre comment l’ocytocine régulait la douleur dans deux différentes régions du cerveau, l’hypothalamus et l’amygdale. Ces travaux ont permis de mettre à jour un petit groupe de neurones ocytocinergiques de l’hypothalamus, qui contrôle la douleur par une action double, à la fois en inhibant la transmission du message douloureux dans la moelle épinière et en contrôlant en même temps l’activité d’autres neurones ocytocinergiques qui sécrètent alors de l’ocytocine dans la circulation sanguine. Dans l’amygdale, nous avons pu montrer que l’effet analgésique de l’ocytocine nécessitait le bon fonctionnement d’un type de cellule non neuronal, l’astrocyte, qui répond à la présence d’ocytocine et, ce faisant, permet l’activation de circuits de neurones contrôlant la douleur.Pain is a complex phenomenon arising from the nervous system. Numerous molecules modulate pain through complex and various mechanisms. One of those, oxytocin, is more famous for its roles in reproduction and social interactions, but is also a potent endogenous analgesic. During this thesis, I tried to understand how oxytocin modulates pain in two brain regions, the hypothalamus and the amygdala. This work unveiled a small group of oxytocinergic neurons in the hypothalamus which control pain through a dual action, firstly by inhibiting the pain signals in the spinal cord and secondly by activating at the same time another population of oxytocinergic neurons, which then secrete oxytocin in the bloodstream. In the amygdala, we showed that the analgesic effect of oxytocin required the proper functioning of a non-neuronal cell type, the astrocyte, which responds to oxytocin and, doing so, allows the activation of neural circuits which modulate pain

    Etude des mécanismes d’action de l’ocytocine sur la modulation des circuits astro-neuronaux de régulation de la douleur

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    Pain is a complex phenomenon arising from the nervous system. Numerous molecules modulate pain through complex and various mechanisms. One of those, oxytocin, is more famous for its roles in reproduction and social interactions, but is also a potent endogenous analgesic. During this thesis, I tried to understand how oxytocin modulates pain in two brain regions, the hypothalamus and the amygdala. This work unveiled a small group of oxytocinergic neurons in the hypothalamus which control pain through a dual action, firstly by inhibiting the pain signals in the spinal cord and secondly by activating at the same time another population of oxytocinergic neurons, which then secrete oxytocin in the bloodstream. In the amygdala, we showed that the analgesic effect of oxytocin required the proper functioning of a non-neuronal cell type, the astrocyte, which responds to oxytocin and, doing so, allows the activation of neural circuits which modulate pain.La douleur est un phénomène complexe régi par le système nerveux. De nombreuses molécules modulent la douleur par des mécanismes complexes et variés. L’une d’elle, l’ocytocine, est plus connue pour ses rôles dans la reproduction et les interactions sociales, mais est pourtant un puissant agent analgésique endogène. Au cours de cette thèse, j’ai cherché à comprendre comment l’ocytocine régulait la douleur dans deux différentes régions du cerveau, l’hypothalamus et l’amygdale. Ces travaux ont permis de mettre à jour un petit groupe de neurones ocytocinergiques de l’hypothalamus, qui contrôle la douleur par une action double, à la fois en inhibant la transmission du message douloureux dans la moelle épinière et en contrôlant en même temps l’activité d’autres neurones ocytocinergiques qui sécrètent alors de l’ocytocine dans la circulation sanguine. Dans l’amygdale, nous avons pu montrer que l’effet analgésique de l’ocytocine nécessitait le bon fonctionnement d’un type de cellule non neuronal, l’astrocyte, qui répond à la présence d’ocytocine et, ce faisant, permet l’activation de circuits de neurones contrôlant la douleur
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