Roles of the 5-HT2C receptor on zebrafish sociality.

Serotonin (5-HT) receptors have been implicated in social behavior in vertebrates. Zebrafish (Danio rerio) have been increasingly being used behavioral neuroscience to study the neurobiological correlates of behavior, including sociality. Nonetheless, the role of 5-HT2C receptors in different social functions were not yet studied in this species. Zebrafish were treated with the agonist MK-212 (2 mg/kg) or the antagonist RS-102221 (2 mg/kg) and tested in the social interaction and social novelty tests, conditional approach test, or mirror-induced aggressive displays. MK-212 increased preference for an unknown conspecific in the social investigation test, but also increased preference for the known conspecific in the social novelty test; RS-102221, on the other hand, decreased preference in the social investigation test but increased preference for the novel conspecific in the social novelty test. MK-212 also decreased predator inspection in the conditional approach test. While RS-102221 decreased time in the display zone in the mirror-induced aggressive display test, it increased display duration. Overall, these results demonstrate the complex role of 5-HT2C receptors in different social contexts in zebrafish, revealing a participation in social plasticity in vertebrates.

Role of Th17 Cytokines in the Liver's Immune Response during Fatal Yellow Fever: Triggering Cell Damage Mechanisms.

Yellow fever (YF) is an infectious and acute viral haemorrhagic disease that triggers a cascade of host immune responses. We investigated the Th17 cytokine profile in the liver tissue of patients with fatal YF. Liver tissue samples were collected from 26 deceased patients, including 21 YF-positive and 5 flavivirus-negative patients, with preserved hepatic parenchyma architecture, who died of other causes. Histopathological and immunohistochemical analysis were performed on the liver samples to evaluate the Th17 profiles (ROR-γ, STAT3, IL-6, TGF-ß, IL-17A, and IL-23). Substantial differences were found in the expression levels of these markers between the patients with fatal YF and controls. A predominant expression of Th17 cytokine markers was observed in the midzonal region of the YF cases, the most affected area in the liver acinus, compared with the controls. Histopathological changes in the hepatic parenchyma revealed cellular damage characterised mainly by the presence of inflammatory cell infiltrates, Councilman bodies (apoptotic cells), micro/macrovesicular steatosis, and lytic and coagulative necrosis. Hence, Th17 cytokines play a pivotal role in the immunopathogenesis of YF and contribute markedly to triggering cell damage in patients with fatal disease outcomes.

Th22 cytokines and yellow fever: Possible implications for the immunopathogenesis of human liver infection.

Yellow fever (YF) is an infectious disease considered a public health problem in tropical and subtropical areas. YF has many pathophysiological events that are correlated with the host immune response. In this study, the in situ Th22 cytokine profile was evaluated. Liver tissue samples were collected from 21 YFV-positive patients who died of the disease and five flavivirus-negative controls who died of other causes and whose hepatic parenchyma architecture was preserved. Immunohistochemical (IHC) analysis of tissues in the hepatic parenchyma of YF cases showed significantly higher expression of interleukin (IL)-22, IL-13, tumour necrosis factor-alpha, and FGF basic (FGF b) in YFV-positive cases than that in flavivirus-negative controls. These results indicate that the response of Th22 cytokines emerges as an alternative for a better understanding of adaptive immunity in the hepatic parenchyma, highlighting the role of cytokines in the repair and suppressive responses in the immunopathogenesis of YFV infection.

Factors Involved in the Apoptotic Cell Death Mechanism in Yellow Fever Hepatitis.

Yellow fever (YF), a non-contagious infectious disease, is endemic or enzootic to the tropical regions of the Americas and Africa. Periodic outbreaks or epidemics have a significant impact on public health. Programmed cell death, or apoptosis, is generally characterised by distinct morphological changes and energy-dependent biochemical pathways. In this study, we performed immunohistochemistry analysis to identify and quantify proteases and protein targets involved in the cascade that triggers apoptosis in YF virus (YFV)-infected human hepatocytes. Liver tissue samples were collected from 26 individuals, among whom 21 were diagnosed as YF-positive, and five were flavivirus-negative and died due to other causes. The histopathological alterations in YFV-positive cases were characterised by the presence of apoptotic bodies, steatosis, cellular swelling, and extensive necrosis and haemorrhage in the hepatic lobules. Additionally, we observed an abundance of inflammatory infiltrates in the portal tract. The expression of various apoptotic markers in the hepatic parenchyma, including CASPASE 3, CASPASE 8, BAX, FAS, FASL, GRANZYME B, and SURVIVIN, differed between YFV-positive cases and controls. Collectively, this study confirmed the complexity of YFV infection-induced apoptosis in situ. However, our data suggest that apoptosis in liver parenchyma lesions may significantly contribute to the pathogenesis of fatal YF in humans.

Endothelium Activation during Severe Yellow Fever Triggers an Intense Cytokine-Mediated Inflammatory Response in the Liver Parenchyma.

Yellow fever (YF) is a pansystemic disease caused by the yellow fever virus (YFV), the prototype species of the family Flaviviridae and genus Flavivirus, and has a highly complex host-pathogen relationship, in which endothelial dysfunction reflects viral disease tropism. In this study, the in situ endothelial response was evaluated. Liver tissue samples were collected from 21 YFV-positive patients who died due to the disease and five flavivirus-negative controls who died of other causes and whose hepatic parenchyma architecture was preserved. Immunohistochemical analysis of tissues in the hepatic parenchyma of YF cases showed significantly higher expression of E-selectin, P-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and very late antigen-4 in YFV-positive cases than in flavivirus-negative controls. These results indicate that endothelium activation aggravates the inflammatory response by inducing the expression of adhesion molecules that contribute to the rolling, recruitment, migration, and construction of the inflammatory process in the hepatic parenchyma in fatal YF cases.

Natural history predicts patterns of thermal vulnerability in amphibians from the Atlantic Rainforest of Brazil.

In the Brazilian Atlantic Rainforest (AF), amphibians (625 species) face habitat degradation leading to stressful thermal conditions that constrain animal activity (e.g., foraging and reproduction). Data on thermal ecology for these species are still scarce. We tested the hypothesis that environmental occupation affects the thermal tolerance of amphibian species more than their phylogenetic relationships. We evaluated patterns of thermal tolerance of 47 amphibian species by assessing critical thermal maxima and warming tolerances, relating these variables with ecological covariates (e.g., adult macro- and microhabitat and site of larval development). We used mean and maximum environmental temperature, ecological covariates, and morphological measurements in the phylogenetic generalized least squares model selection to evaluate which traits better predict thermal tolerance. We did not recover phylogenetic signal under a Brownian model; our results point to a strong association between critical thermal maxima and habitat and development site. Forest species were less tolerant to warm temperatures than open area or generalist species. Species with larvae that develop in lentic environment were more tolerant than those in lotic ones. Thus, species inhabiting forest microclimates are more vulnerable to the synergistic effect of habitat loss and climate change. We use radar charts as a quick evaluation tool for thermal risk diagnoses using aspects of natural history as axes.

Third times a charm: reviewing the advertisement call of Gabohyla pauloalvini (Anura: Hylidae: Scinaxinae), an endemic species from Brazil Atlantic Forest.

The Neotropical tribe Sphaenorhynchini is composed of 15 recognized species commonly named as lime treefrogs. Gabohyla pauloalvini occurs in Atlantic Forest lowlands through the states of Bahia and Esprito Santo, Brazil. Based on field observation, literature review, and evaluation of audio files, we conclude that previous bioacoustic descriptions were erroneously assigned to G. pauloalvini. Here, we describe for the first time the advertisement call of G. pauloalvini from two disjunct populations. In addition, we provide new distribution records and an updated map for this species. The advertisement call of G. pauloalvini is composed of 15 closely spaced notes, with duration of 0.0161.976 s, inter-note intervals of 0.3401.25 s, and an average dominant frequency (= fundamental frequency) of 4966.0 Hz. Harmonics are visible in the spectrogram. Three new populations of G. pauloalvini have been recorded and extended the distribution by 60 km south. Nevertheless, G. pauloalvini is still known only from few localities. We highlight the importance of depositing audio recordings and specimens in scientific collections to promote systematics and natural history studies.

The advertisement call of the rare casque-headed frog Nyctimantis galeata (Anura: Hylidae) from its type locality, Morro do Chapéu, Bahia, Brazil.

Nyctimantis Boulenger, 1882 was considered a monotypic genus for over a century. In a recent phylogenetic analysis of the Lophyohylini tribe with more than 96% of its representatives, Nyctimantis was redefined with the well-supported inclusion of some species from the genus Aparasphenodon, Argenteohyla and Corythomantis (Blotto et al. 2020). Therefore, the genus Nyctimantis currently consists of seven described species: N. arapapa (Pimenta, Napoli Haddad, 2009); N. bokermanni (Pombal, 1993); N. brunoi (Miranda-Ribeiro, 1920); N. galeata (Pombal, Menezes, Fontes, Nunes, Rocha Van Sluys, 2012); N. pomba (Assis, Santana, Silva, Quintela Feio, 2013); N. rugiceps Boulenger (1882) and N. siemersi (Mertens, 1937).

Redescription of the tadpole of Leptodactylus flavopictus Lutz, 1926 (Anura: Leptodactylidae) from Pilar do Sul, São Paulo, Brazil.

Frogs of the subfamily Leptodactylinae Werner can be found from southern Texas (USA) to southern Brazil, including the northern Antilles (Frost 2019). This subfamily is composed of 98 recognized species and the genus Leptodactylus Fitzinger contains the largest number of species (74 sp.) (Frost 2019). A study conducted by de Sá et al. (2014) provided a phylogeny of Leptodactylus based on molecular analysis, adult and larval morphology, and behavioral data. Currently, four species groups are recognized within this genus: L. fuscus group, L. pentadactylus group, L. latrans group, and L. melanonotus group (de Sá et al. 2014).

Searching for Networks: Ecological Connectivity for Amphibians Under Climate Change.

Ecological connectivity depends on key elements within the landscape, which can support ecological fluxes, species richness and long-term viability of a biological community. Landscape planning requires clear aims and quantitative approaches to identify which key elements can reinforce the spatial coherence of protected areas design. We aim to explore the probability of the ecological connectivity of forest remnants and amphibian species distributions for current and future climate scenarios across the Central Corridor of the Brazilian Atlantic Forest. Integrating amphibian conservation, climate change and ecological corridors, we design a landscape ranking based on graph and circuit theories. To identify the sensitivity of connected areas to climate-dependent changes, we use the Model for Interdisciplinary Research on Climate by means of simulations for 2080-2100, representing a moderated emission scenario within an optimistic context. Our findings indicate that more than 70% of forest connectivity loss by climate change may drastically reduce amphibian dispersal in this region. We show that high amphibian turnover rates tend to be greater in the north-eastern edges of the corridor across ensembles of forecasts. Our spatial analysis reveals a general pattern of low-conductance areas in landscape surface, yet with some well-connected patches suggesting potential ecological corridors. Atlantic Forest reserves are expected to be less effective in a near future. For improved conservation outcomes, we recommend some landscape paths with low resistance values across space and time. We highlight the importance of maintaining forest remnants in the southern Bahia region by drafting a blueprint for functional biodiversity corridors.

Diversity of miniaturized frogs of the genus Adelophryne (Anura: Eleutherodactylidae): A new species from the Atlantic Forest of northeast Brazil.

The number of species of frogs in the South American genus Adelophryne has increased in recent years, and it has become apparent that this group contains a substantial amount of undescribed diversity. Currently the genus contains nine described species and five candidate species. Here we describe the tenth species of the genus Adelophryne from the municipality of Igrapiúna, southern Bahia state, Brazil. The new species is characterized by its small body size, indistinct tympanum, and two phalanges in the finger IV. The species of the genus are distributed in three groups, Northern Amazonia Clade, Northern Atlantic Forest Clade and Southern Atlantic Forest Clade. The new species is phylogenetically related to species of the Northern Atlantic Forest Clade of Adelophryne and restricted to forested habitat, as typical for other Adelophryne. The species is restricted to the pristine forests in the type locality, and we consider its conservation status as Near Threatened. New morphological and molecular data of other Adelophryne species are presented, extending the distribution of Adelophryne sp. 2, Adelophryne sp. 4, Adelophryne mucronata and Adelophryne glandulata. However, a more comprehensive revision of the diversity and phylogenetic position of most Adelophryne species is needed, and the evolutionary relationships of A. meridionalis and A. pachydactyla remain unknown.

Amphibians of the Reserva Ecológica Michelin: a high diversity site in the lowland Atlantic Forest of southern Bahia, Brazil.

An inventory of the amphibians of the Reserva Ecológica Michelin - REM in southern Bahia, Brazil is presented. Sixty-nine species were recorded during a ten-year sampling period. Amphibians were distributed in two orders (Gymnophiona and Anura), belonging to twelve families [Aromobatidae (1), Bufonidae (3), Centrolenidae (1), Craugastoridae (5), Eleutherodactylidae (3), Hemiphractidae (2), Hylidae (34), Phyllomedusidae (5) Leptodactylidae (7), Microhylidae (4), Odontophrynidae (3) and Caeciliidae (1)]. Fifty per cent of the reproductive modes known for Atlantic forest anurans were recorded. While no threatened species were found at REM, six species are classified as data deficient (DD) by the Brazilian Red List of threatened species and deserve additional attention. Phasmahyla timbo and Vitreorana eurygnatha are listed as endangered in Bahia according to the list of threatened species of the state. Despite a higher diversity of amphibians in the Atlantic forest having been reported for mountainous regions, our results revealed that amphibian richness for lowland forests is also high.

The tadpole of Dendropsophus novaisi (Bokermann, 1968) (Anura: Hylidae), with comments on natural history.

Several frog species descriptions from this century provide larval morphology, acoustical, molecular, ecological and behavioral information that, together, provide a better species characterization (e.g., Glos et al. 2005; Toledo et al. 2010; Vassilieva et al. 2016). For the majority of anuran species, basic information is still lacking, despite being fundamental to understand the evolution of a taxonomic unit as well as phylogenetic relationships established between taxa. Such information can be particularly useful for species groups with unresolved taxonomic issues, such as the Dendropsophus marmoratus group (Bokermann 1964; Heyer 1977; Caramaschi Jim 1983; Gomes Peixoto 1996).

Talbot effect in optical lattices with topological charge.

We studied the interference resulting from the superposition of optical lattices, which are non-diffracting fields propagating in free space, and showed a Talbot self-imaging effect. These lattices are formed by spatially Fourier transforming a "quasi"-orbital angular momentum (OAM) state. We experimentally observed that although the Talbot images change, the Talbot length is insensitive to the topological charge of the "quasi"-OAM state. Our findings can be useful for laser-written photonic lattices.

The advertisement call and comments on the distribution of Eleutherodactylus bilineatus Bokermann, 1975, an endemic frog of Bahia State, Brazil (Amphibia, Anura).

Advertisement calls can be used to aid solving taxonomic problems and understanding the evolution of certain groups. In this study, the advertisement call of Eleutherodactylus bilineatus is described. It is composed by two different notes with a total duration of 0.529-4.241 seconds and dominant frequency of 1.72-3.45 kHz. Additionally, new data is provided on the geographical distribution of Eleutherodactylus bilineatus and the most inland record for this species.

Complete genome sequences of three Pseudomonas aeruginosa isolates with phenotypes of polymyxin B adaptation and inducible resistance.

Clinical "superbug" isolates of Pseudomonas aeruginosa were previously observed to be resistant to several antibiotics, including polymyxin B, and/or to have a distinct, reproducible adaptive polymyxin resistance phenotype, identified by observing "skipped" wells (appearance of extra turbid wells) during broth microdilution testing. Here we report the complete assembled draft genome sequences of three such polymyxin resistant P. aeruginosa strains (9BR, 19BR, and 213BR).

Evaluation of Bauhinia monandra aqueous and ethanol extracts in pregnant rats.

Bauhinia monandra Kurz. (Fabaceae: Caesalpinioideae) is a plant widely employed in Brazilian folk medicine for hypoglycemia. However, little is known about the effect of maternal exposure to this plant on fetal development. The aqueous and ethanol extracts obtained from B. monandra dried leaves were administered to pregnant Wistar rats throughout gestation (day 1 to day 20) at 1,400 or 7,000 mg/kg/day (n = 6/group). Maternal toxicity was not observed in the dams of both groups, and was evaluated by observing body weight, water and food intake during treatment, by measuring serum biochemical levels of creatinine, urea, AST and ALT, and by studying the histopathology of liver, kidney, pancreas, spleen and uterus at the end of treatment (gestation day 20). Both extracts and doses did not impair reproductive performance or delay fetal development, measured by observing implantations and reabsorptions in the uterus, by counting the number of corpora lutea in ovaries, by recording the litter weight and number of live and dead fetuses and by analyzing possible skeleton and viscera malformations in the fetuses. Also, the aqueous extract promoted decreased post-implantation loss when compared to the control group. The aqueous and ethanol extracts from B. monandra dried leaves (1,400 or 7,000 mg/kg/day) did not cause maternal or fetal toxicities and the aqueous extract promoted increased implantation and decreased post-implantation loss in the pregnant rats.