Live calcium imaging of Aedes aegypti neuronal tissues reveals differential importance of chemosensory systems for life-history-specific foraging strategies.

BackgroundThe mosquito Aedes aegypti has a wide variety of sensory pathways that have supported its success as a species as well as a highly competent vector of numerous debilitating infectious pathogens. Investigations into mosquito sensory systems and their effects on behavior are valuable resources for the advancement of mosquito control strategies. Numerous studies have elucidated key aspects of mosquito sensory systems, however there remains critical gaps within the field. In particular, compared to that of the adult form, there has been a lack of studies directed towards the immature life stages. Additionally, although numerous studies have pinpointed specific sensory receptors as well as responding motor outputs, there has been a lack of studies able to monitor both concurrently.ResultsTo begin filling aforementioned gaps, here we engineered Ae. aegypti to ubiquitously express a genetically encoded calcium indicator, GCaMP6s. Using this strain, combined with advanced microscopy, we simultaneously measured live stimulus-evoked calcium responses in both neuronal and muscle cells with a wide spatial range and resolution.ConclusionsBy coupling in vivo live calcium imaging with behavioral assays we were able to gain functional insights into how stimulus-evoked neural and muscle activities are represented, modulated, and transformed in mosquito larvae enabling us to elucidate mosquito sensorimotor properties important for life-history-specific foraging strategies

Palliative psychiatry in a narrow and in a broad sense: A concept clarification

Even with optimal treatment, some persons with severe and persistent mental illness do not achieve a level of mental health, psychosocial functioning and quality of life that is acceptable to them. With each unsuccessful treatment attempt, the probability of achieving symptom reduction declines while the probability of somatic and psychological side effects increases. This worsening benefit-harm ratio of treatment aiming at symptom reduction has motivated calls for implementing palliative approaches to care into psychiatry (palliative psychiatry). Palliative psychiatry accepts that some cases of severe and persistent mental illness can be irremediable and calls for a careful evaluation of goals of care in these cases. It aims at reducing harm, relieving suffering and thus improving quality of life directly, working around irremediable psychiatric symptoms. In a narrow sense, this refers to patients likely to die of their severe and persistent mental illness soon, but palliative psychiatry in a broad sense is not limited to end-of-life care. It can - and often should - be integrated with curative and rehabilitative approaches, as is the gold standard in somatic medicine. Palliative psychiatry constitutes a valuable addition to established non-curative approaches such as rehabilitative psychiatry (which focuses on psychosocial functioning instead of quality of life) and personal recovery (a journey that persons living with severe and persistent mental illness may undertake, not necessarily accompanied by mental health care professionals). Although the implementation of palliative psychiatry is met with several challenges such as difficulties regarding decision-making capacity and prognostication in severe and persistent mental illness, it is a promising new approach in caring for persons with severe and persistent mental illness, regardless of whether they are at the end of life. Keywords: Severe and persistent mental illness; end of life; futility; goals of care; irremediability; palliative psychiatry; quality of life; sufferin

Cochlear Implant–Evoked Cortical Activation in Children With Cochlear Nerve Deficiency

To report the results of cochlear implant-elicited cortical auditory evoked potentials (eCAEP) in children with cochlear nerve deficiency (CND)

Engineered Reproductively Isolated Species Drive Reversible Population Replacement

Engineered reproductive species barriers are useful for impeding gene flow and driving desirable genes into wild populations in a reversible threshold-dependent manner. However, methods to generate synthetic barriers have not been developed in advanced eukaryotes. To overcome this challenge, we engineered SPECIES (Synthetic Postzygotic barriers Exploiting CRISPR-based Incompatibilities for Engineering Species) to generate postzygotic reproductive barriers. Using this approach, we engineer multiple reproductively isolated SPECIES and demonstrate their threshold-dependent gene drive capabilities in D. melanogaster. Given the near-universal functionality of CRISPR tools, this approach should be portable to many species, including insect disease vectors in which confinable gene drives could be of great practical utility

Engineered resistance to Zika virus in transgenic Aedes aegypti expressing a polycistronic cluster of synthetic small RNAs

Recent Zika virus (ZIKV) outbreaks have highlighted the necessity for development of novel vector control strategies to combat arboviral transmission, including genetic versions of the sterile insect technique, artificial infection with Wolbachia to reduce population size and/or vectoring competency, and gene drive-based methods. Here, we describe the development of mosquitoes synthetically engineered to impede vector competence to ZIKV. We demonstrate that a polycistronic cluster of engineered synthetic small RNAs targeting ZIKV is expressed and fully processed in Aedes aegypti, ensuring the formation of mature synthetic small RNAs in the midgut where ZIKV resides in the early stages of infection. Critically, we demonstrate that engineered Ae. aegypti mosquitoes harboring the anti-ZIKV transgene have significantly reduced viral infection, dissemination, and transmission rates of ZIKV. Taken together, these compelling results provide a promising path forward for development of effective genetic-based ZIKV control strategies, which could potentially be extended to curtail other arboviruses

Broad Dengue Neutralization in Mosquitoes Expressing an Engineered Antibody

With dengue virus (DENV) becoming endemic in tropical and subtropical regions worldwide, there is a pressing global demand for effective strategies to control the mosquitoes that spread this disease. Recent advances in genetic engineering technologies have made it possible to create mosquitoes with reduced vector competence, limiting their ability to acquire and transmit pathogens. Here we describe the development of Aedes aegypti mosquitoes synthetically engineered to impede vector competence to DENV. These mosquitoes express a gene encoding an engineered single-chain variable fragment derived from a broadly neutralizing DENV human monoclonal antibody and have significantly reduced viral infection, dissemination, and transmission rates for all four major antigenically distinct DENV serotypes. Importantly, this is the first engineered approach that targets all DENV serotypes, which is crucial for effective disease suppression. These results provide a compelling route for developing effective genetic-based DENV control strategies, which could be extended to curtail other arboviruses

Parasitic nematode fatty acid- and retinol-binding proteins compromise host immunity by interfering with host lipid signaling pathways

Parasitic nematodes cause significant morbidity and mortality globally. Excretory/secretory products (ESPs) such as fatty acid- and retinol- binding proteins (FARs) are hypothesized to suppress host immunity during nematode infection, yet little is known about their interactions with host tissues. Leveraging the insect parasitic nematode, Steinernema carpocapsae, we describe here the first in vivo study demonstrating that FARs modulate animal immunity, causing an increase in susceptibility to bacterial co-infection. Moreover, we show that FARs dampen key components of the fly immune response including the phenoloxidase cascade and antimicrobial peptide (AMP) production. Our data also reveal that FARs deplete lipid signaling precursors in vivo as well as bind to these fatty acids in vitro, suggesting that FARs elicit their immunomodulatory effects by altering the availability of lipid signaling molecules necessary for an efficient immune response. Collectively, these data support a complex role for FARs in immunosuppression in animals and provide detailed mechanistic insight into parasitism in phylum Nematoda