Beyond new neurons in the adult hippocampus: imipramine acts as a pro-astrogliogenic factor and rescues cognitive impairments induced by stress exposure

Depression is a prevalent, socially burdensome disease. Different studies have demonstrated the important role of astrocytes in the pathophysiology of depression as modulators of neurotransmission and neurovascular coupling. This is evidenced by astrocyte impairments observed in brains of depressed patients and the appearance of depressive-like behaviors upon astrocytic dysfunctions in animal models. However, little is known about the importance of de novo generated astrocytes in the mammalian brain and in particular its possible involvement in the precipitation of depression and in the therapeutic actions of current antidepressants (ADs). Therefore, we studied the modulation of astrocytes and adult astrogliogenesis in the hippocampal dentate gyrus (DG) of rats exposed to an unpredictable chronic mild stress (uCMS) protocol, untreated and treated for two weeks with antidepressants—fluoxetine and imipramine. Our results show that adult astrogliogenesis in the DG is modulated by stress and imipramine. This study reveals that distinct classes of ADs impact differently in the astrogliogenic process, showing different cellular mechanisms relevant to the recovery from behavioral deficits induced by chronic stress exposure. As such, in addition to those resident, the newborn astrocytes in the hippocampal DG might also be promising therapeutic targets for future therapies in the neuropsychiatric field.ARMS: ELC, NDA, PP, AMP, JSC, MM, AJR, JFO, and L.P. received fellowships from the Portuguese Foundation for Science and Technology (FCT) (IF/00328/2015 to J.F.O.; 2020.02855.CEECIND to LP). This work was funded by FCT (IF/01079/2014, PTDC/MED-NEU/31417/2017 Grant to JFO), BIAL Foundation Grants (037/18 to J.F.O. and 427/14 to L.P.), “la Caixa” Foundation Health Research Grant (LCF/PR/HR21/52410024) and Nature Research Award for Driving Global Impact—2019 Brain Sciences (to L.P.). This was also co-funded by the Life and Health Sciences Research Institute (ICVS), and by FEDER, through the Competitiveness Internationalization Operational Program (POCI), and by National funds, through the Foundation for Science and Technology (FCT)—project UIDB/50026/2020 and UIDP/50026/2020. Moreover, this work has been funded by ICVS Scientific Microscopy Platform, member of the national infrastructure PPBI—Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122; by National funds, through the Foundation for Science and Technology (FCT)—project UIDB/50026/2020 and UIDP/50026/2020; “la Caixa” Foundation (ID 100010434 to A.J.R.), under the agreement LCF/PR/HR20/52400020; and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 101003187 to A.J.R.)

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Citogénese no Hilus hippocampal: nova fonte de plasticidade neuronal no cérebro de mamíferos adultos?

Dissertação de mestrado em Ciências da SaúdeThe continuous capacity to generate new neuronal and glial cells, a process known as adult brain cytogenesis, persists in restricted niches of the adult mammalian brain. This phenomenon occurs traditionally in two regions: the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG) and the periventricular subependymal zone. The dentate gyrus has been classically involved in important brain functions such as learning and memory. Beyond the participation in cognitive processing, the newborn neurons have been also shown to be important for several emotion domains. Despite the fact that brain cytogenesis in rodents is well accepted, the functional importance of adult neurogenesis in mammals has been a matter of much debate. Just recently, discussion around this fundamental subject of neurosciences was stirred up. The dentate hilus is one of the most complex and cellular diverse sub-regions of the hippocampal formation with a central role in key cognitive hippocampal functions. Few descriptions exist of cytogenesis in the adult hilus. Moreover, the field lacks a morphological and functional characterization of hilar newborn cells. Hence this work provides an unprecedented neuroanatomical description of hilar cytogenesis complemented with insights on its extrinsic modulation, in the adult rat brain. Results show that newborn hilar cells acquire neuroblasts’ cell markers, although they present more incipient cytomorphological traits, when compared to their subgranular counterparts. Contrarily to SGZ neurogenesis, newborn hilar neurons do not express the final maturation marker, NeuN. A significantly small fraction of new hilar cells within the hilus reflect the astrogliogenic process, described to be ubiquitous in the adult brain. Even though the number of newborn cells in the hilus is lower than in the SGZ, that region emerges as an important niche of neural plasticity. Indeed, stress exposure, physical activity and treatment with psychotropic drugs differentially modulate hilar cytogenesis. Work on this thesis improves current knowledge on structural plasticity of the adult mammalian brain, and revisits pre-established notions on the regional distribution and functional importance of post-natal neuro- and gliogenic niches.A capacidade contínua de gerar novos neurónios e células gliais, processo denominado citogénese cerebral, é restrita a determinados locais do cérebro adulto. Tradicionalmente, este fenómeno ocorre em dois locci cerebrais: na zona subgranular (ZSG) do girus dentado (GD) do hipocampo e na zona subependimal. O GD tem sido classicamente implicado em importantes funções cognitivas como a aprendizagem e memóriae também participam em domínios emocionais. Apesar da citogénese cerebral adulta ser consensualmente aceite em roedores, a importância funcional da neurogénese adulta tem sido consideravelmente debatida. Mais recentemente, a discussão em torno deste tema reemergiu, em particular no cérebro humano. Em íntima relação com o GD, a região hilar é uma das estruturas pertencentes à formação hipocampal mais complexas e celularmente diversificada, também esta com um papel importante para funções cognitivas de controlo hipocampal. Observações prévias, sugerem que também esta região hipocampal possa ser populada por células recém geradas no cérebro adulto. A informação sobre fenómenos citogénicos hilares no cérebro adulto mamífero é escassa, não existindo caracterização morfológica ou funcional das novas células no hilus. Assim, este trabalho engloba a primeira descrição neuroanatómica da citogénese hilar, complementada com o estudo da sua modulação por fatores extrínsecos em ratos adultos. Os resultados demonstram que as novas células hilares adquirirem marcadores de neuroblastos, pese embora o facto de exibirem características citomorfológicas mais incipientes, quando comparadas com neuroblastos subgranulares. Ao contrário do que acontece na neurogénese da ZSG, os novos neurónios não expressam o marcador de maturação terminal NeuN. Uma fracção diminuta das novas células hilares, diz respeito a fenómenos astrogliogénicos, ubíquos no cérebro adulto. Apesar do número de novas células residentes no hilus ser significativamente inferior àquele da ZSG, esta região parece ser um importante nicho de plasticidade neural. A exposição a fatores de stress, atividade física e tratamento com fármacos psicotrópicos, modulam a citogénese hilar diferencialmente. O trabalho desenvolvido nesta tese aumenta o conhecimento atual sobre a plasticidade estrutural do cérebro mamífero adulto, revisitando noções pré-estabelecidas sobre a distribuição regional e importância funcional dos nichos neuro- e gliogénicos pós-natais.O trabalho apresentado nesta tese foi desenvolvido no Instituto de Investigação em Ciências da Vida e Saúde (ICVS), Universidade do Minho sendo financiado pela FCT (IF/01079/2014). O Suporte financeiro também foi fornecido pelo projeto NORTE-01-0145-FEDER-000013, apoiado pelo Programa Operacional Regional do Norte (NORTE 2020), sob a parceria com Portugal 2020 através do Fundo Europeu de Desenvolvimento Regional (FEDER), e financiado por fundos da FEDER pelo Programa Operacional Competitividade e Internacionalização (COMPETE), e por fundos nacionais pela Fundação para a Ciência e Tecnologia (FCT) sob o projeto POCI-01-0145-FEDER-007038. Este trabalho também teve o apoio financeiro da Behavioral & Molecular Lab (Bn’ML)

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved