Altered functional connectivity and network excitability in a model of cortical dysplasia

Abstract Focal cortical dysplasias (FCDs) are malformations of cortical development that often result in medically refractory epilepsy, with a greater incidence in the pediatric population. The relationship between the disturbed cortical morphology and epileptogenic activity of FCDs remains unclear. We used the BCNU (carmustine 1-3-bis-chloroethyl-nitrosourea) animal model of cortical dysplasia to evaluate neuronal and laminar alterations and how these result in altered activity of intracortical networks in early life. We corroborated the previously reported morphological anomalies characteristic of the BCNU model, comprising slightly larger and rounder neurons and abnormal cortical lamination. Next, the neuronal activity of live cortical slices was evaluated through large field-of-view calcium imaging as well as the neuronal response to a stimulus that leads to cortical hyperexcitability (pilocarpine). Examination of the joint activity of neuronal calcium time series allowed us to identify intracortical communication patterns and their response to pilocarpine. The baseline power density distribution of neurons in the cortex of BCNU-treated animals was different from that of control animals, with the former showing no modulation after stimulus. Moreover, the intracortical communication pattern differed between the two groups, with cortexes from BCNU-treated animals displaying decreased inter-layer connectivity as compared to control animals. Our results indicate that the altered anatomical organization of the cortex of BCNU-treated rats translates into altered functional networks that respond abnormally to a hyperexcitable stimulus and highlight the role of network dysfunction in the pathophysiology of cortical dysplasia

Vectorial capacity of Aedes aegypti for dengue virus type 2 is reduced with co-infection of Metarhizium anisopliae

Background: Aedes aegypti, is the major dengue vector and a worldwide public health threat combated basically by chemical insecticides. In this study, the vectorial competence of Ae. aegypti co-infected with a mildly virulent Metarhizium anisopliae and fed with blood infected with the DENV-2 virus, was examined.\ud \ud Methodology/Principal Findings: The study encompassed three bioassays (B). In B1 the median lethal time (LT50) of Ae. aegypti exposed to M. anisopliae was determined in four treatments: co-infected (CI), single-fungus infection (SF), single-virus infection (SV) and control (C). In B2, the mortality and viral infection rate in midgut and in head were registered in fifty females of CI and in SV. In B3, the same treatments as in B1 but with females separated individually were tested to evaluate the effect on fecundity and gonotrophic cycle length. Survival in CI and SF females was 70% shorter than the one of those in SV and control. Overall viral infection rate in CI and SV were 76 and 84% but the mortality at day six post-infection was 78% (54% infected) and 6% respectively. Survivors with virus in head at day seven post-infection were 12 and 64% in both CI and SV mosquitoes. Fecundity and gonotrophic cycle length were reduced in 52 and 40% in CI compared to the ones in control.\ud \ud Conclusion/Significance: Fungus-induced mortality for the CI group was 78%. Of the survivors, 12% (6/50) could potentially transmit DENV-2, as opposed to 64% (32/50) of the SV group, meaning a 5-fold reduction in the number of infective mosquitoes. This is the first report on a fungus that reduces the vectorial capacity of Ae. aegypti infected with the DENV-2 virus

Integrating climate adaptation and transboundary management: Guidelines for designing climate-smart marine protected areas

Climate change poses an urgent threat to biodiversity that demands societal responses. The magnitude of this challenge is reflected in recent international commitments to protect 30% of the planet by 2030 while adapting to climate change. However, because climate change is global, interventions must transcend political boundaries. Here, using the California Bight as a case study, we provide 21 biophysical guidelines for designing climate-smart transboundary marine protected area (MPA) networks and conduct analyses to inform their application. We found that future climates and marine heatwaves could decrease ecological connectivity by 50% and hinder the recovery of vulnerable species in MPAs. To buffer the impacts of climate change, MPA coverage should be expanded, focusing on protecting critical nodes for the network and climate refugia, where impacts might be less severe. For shared ecoregions, these actions require international coordination. Our work provides the first comprehensive framework for integrating climate resilience for MPAs in transboundary ecoregions, which will support other nations’ aspirations. © 2023 The AuthorsOpen access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Integrating climate adaptation and transboundary management:Guidelines for designing climate-smart marine protected areas

Climate change poses an urgent threat to biodiversity that demands societal responses. The magnitude of this challenge is reflected in recent international commitments to protect 30% of the planet by 2030 while adapting to climate change. However, because climate change is global, interventions must transcend political boundaries. Here, using the California Bight as a case study, we provide 21 biophysical guidelines for designing climate-smart transboundary marine protected area (MPA) networks and conduct analyses to inform their application. We found that future climates and marine heatwaves could decrease ecological connectivity by 50% and hinder the recovery of vulnerable species in MPAs. To buffer the impacts of climate change, MPA coverage should be expanded, focusing on protecting critical nodes for the network and climate refugia, where impacts might be less severe. For shared ecoregions, these actions require international coordination. Our work provides the first comprehensive framework for integrating climate resilience for MPAs in transboundary ecoregions, which will support other nations’ aspirations.</p