Thermosensory behaviors of the free-living life stages of Strongyloides species support parasitism in tropical environments.

Soil-transmitted parasitic nematodes infect over 1 billion people worldwide and are a common source of neglected disease. Strongyloides stercoralis is a potentially fatal skin-penetrating human parasite that is endemic to tropical and subtropical regions around the world. The complex life cycle of Strongyloides species is unique among human-parasitic nematodes in that it includes a single free-living generation featuring soil-dwelling, bacterivorous adults whose progeny all develop into infective larvae.

Thermosensory behaviors of the free-living life stages of species support parasitism in tropical environments.

Soil-transmitted parasitic nematodes infect over 1 billion people worldwide and are a common source of neglected disease. is a potentially fatal skin-penetrating human parasite that is endemic to tropical and subtropical regions around the world. The complex life cycle of species is unique among human-parasitic nematodes in that it includes a single free-living generation featuring soil-dwelling, bacterivorous adults whose progeny all develop into infective larvae.

The RNA-seq Browser: a web-based application for on-demand analysis of publicly available spp. bulk RNA-sequencing data.

The RNA-seq Browser is an open-source Shiny web app that enables on-demand visualization and quantification of bulk RNA-sequencing data for five species: , , , , and . The app is designed to allow researchers without previous coding experience to interactively explore publicly available RNA-sequencing data. Key app features include the ability to plot gene expression across life stages for user-specified gene sets, and modules for performing differential gene expression analyses.

Systemic Immune Modulation by Gastrointestinal Nematodes.

Gastrointestinal nematode (GIN) infection has applied significant evolutionary pressure to the mammalian immune system and remains a global economic and human health burden. Upon infection, type 2 immune sentinels activate a common antihelminth response that mobilizes and remodels the intestinal tissue for effector function; however, there is growing appreciation of the impact GIN infection also has on the distal tissue immune state. Indeed, this effect is observed even in tissues through which GINs never transit.

A standard workflow for community-driven manual curation of genome annotations.

Advances in the functional genomics and bioinformatics toolkits for species have positioned these species as genetically tractable model systems for gastrointestinal parasitic nematodes. As community interest in mechanistic studies of species continues to grow, publicly accessible reference genomes and associated genome annotations are critical resources for researchers. Genome annotations for multiple species are broadly available via the WormBase and WormBase ParaSite online repositories.

The neural basis of heat seeking in a human-infective parasitic worm.

Soil-transmitted parasitic nematodes infect over one billion people and cause devastating morbidity worldwide. Many of these parasites have infective larvae that locate hosts using thermal cues. Here, we identify the thermosensory neurons of the human threadworm Strongyloides stercoralis and show that they display unique functional adaptations that enable the precise encoding of temperatures up to human body temperature.

The Wild Worm Codon Adapter: a web tool for automated codon adaptation of transgenes for expression in non-Caenorhabditis nematodes.

Advances in genomics techniques are expanding the range of nematode species that are amenable to transgenesis. Due to divergent codon usage biases across species, codon optimization is often a critical step for the successful expression of exogenous transgenes in nematodes. Platforms for generating DNA sequences codon-optimized for the free-living model nematode Caenorhabditis elegans are broadly available.

Strongyloides RNA-seq Browser: a web-based software platform for on-demand bioinformatics analyses of Strongyloides species.

Soil-transmitted gastrointestinal parasitic nematodes infect approximately 1 billion people worldwide, predominantly in low-resource communities. Skin-penetrating gastrointestinal nematodes in the genus Strongyloides are emerging as model systems for mechanistic studies of soil-transmitted helminths due to the growing availability of functional genomics tools for these species. To facilitate future genomics studies of Strongyloides species, we have designed a web-based application, the Strongyloides RNA-seq Browser, that provides an open source, user-friendly portal for accessing and analyzing Strongyloides genomic expression data.

Chemosensory mechanisms of host seeking and infectivity in skin-penetrating nematodes.

Approximately 800 million people worldwide are infected with one or more species of skin-penetrating nematodes. These parasites persist in the environment as developmentally arrested third-stage infective larvae (iL3s) that navigate toward host-emitted cues, contact host skin, and penetrate the skin. iL3s then reinitiate development inside the host in response to sensory cues, a process called activation.

Terror in the dirt: Sensory determinants of host seeking in soil-transmitted mammalian-parasitic nematodes.

Infection with gastrointestinal parasitic nematodes is a major cause of chronic morbidity and economic burden around the world, particularly in low-resource settings. Some parasitic nematode species, including the human-parasitic threadworm Strongyloides stercoralis and human-parasitic hookworms in the genera Ancylostoma and Necator, feature a soil-dwelling infective larval stage that seeks out hosts for infection using a variety of host-emitted sensory cues. Here, we review our current understanding of the behavioral responses of soil-dwelling infective larvae to host-emitted sensory cues, and the molecular and cellular mechanisms that mediate these responses.

Temperature-dependent behaviors of parasitic helminths.

Parasitic helminth infections are the most common source of neglected tropical disease among impoverished global communities. Many helminths infect their hosts via an active, sensory-driven process in which environmentally motile infective larvae position themselves near potential hosts. For these helminths, host seeking and host invasion can be divided into several discrete behaviors that are regulated by both host-emitted and environmental sensory cues, including heat.

A Critical Role for Thermosensation in Host Seeking by Skin-Penetrating Nematodes.

Skin-penetrating parasitic nematodes infect approximately one billion people worldwide and are a major source of neglected tropical disease [1-6]. Their life cycle includes an infective third-larval (iL3) stage that searches for hosts to infect in a poorly understood process that involves both thermal and olfactory cues. Here, we investigate the temperature-driven behaviors of skin-penetrating iL3s, including the human-parasitic threadworm Strongyloides stercoralis and the human-parasitic hookworm Ancylostoma ceylanicum.

Cholinergic control of gamma power in the midbrain spatial attention network.

The modulation of gamma power (25-90 Hz) is associated with attention and has been observed across species and brain areas. However, mechanisms that control these modulations are poorly understood. The midbrain spatial attention network in birds generates high-amplitude gamma oscillations in the local field potential that are thought to represent the highest priority location for attention.

Spatially reciprocal inhibition of inhibition within a stimulus selection network in the avian midbrain.

Reciprocal inhibition between inhibitory projection neurons has been proposed as the most efficient circuit motif to achieve the flexible selection of one stimulus among competing alternatives. However, whether such a motif exists in networks that mediate selection is unclear. Here, we study the connectivity within the nucleus isthmi pars magnocellularis (Imc), a GABAergic nucleus that mediates competitive selection in the midbrain stimulus selection network.

Enhanced NMDA receptor-dependent thalamic excitation and network oscillations in stargazer mice.

Disturbances in corticothalamic circuitry can lead to absence epilepsy. The reticular thalamic nucleus (RTN) plays a pivotal role in that it receives excitation from cortex and thalamus and, when strongly activated, can generate excessive inhibitory output and epileptic thalamocortical oscillations that depend on postinhibitory rebound. Stargazer (stg) mice have prominent absence seizures resulting from a mutant form of the AMPAR auxiliary protein stargazin.

A new mode of corticothalamic transmission revealed in the Gria4(-/-) model of absence epilepsy.

Cortico-thalamo-cortical circuits mediate sensation and generate neural network oscillations associated with slow-wave sleep and various epilepsies. Cortical input to sensory thalamus is thought to mainly evoke feed-forward synaptic inhibition of thalamocortical (TC) cells via reticular thalamic nucleus (nRT) neurons, especially during oscillations. This relies on a stronger synaptic strength in the cortico-nRT pathway than in the cortico-TC pathway, allowing the feed-forward inhibition of TC cells to overcome direct cortico-TC excitation.

Maintenance of thalamic epileptiform activity depends on the astrocytic glutamate-glutamine cycle.

The generation of prolonged neuronal activity depends on the maintenance of synaptic neurotransmitter pools. The astrocytic glutamate-glutamine cycle is a major mechanism for recycling the neurotransmitters GABA and glutamate. Here we tested the effect of disrupting the glutamate-glutamine cycle on two types of neuronal activity patterns in the thalamus: sleep-related spindles and epileptiform oscillations.