Modulation of Stiffness-Dependent Macrophage Inflammatory Responses by Collagen Deposition.

Macrophages are innate immune cells that interact with complex extracellular matrix environments, which have varied stiffness, composition, and structure, and such interactions can lead to the modulation of cellular activity. Collagen is often used in the culture of immune cells, but the effects of substrate functionalization conditions are not typically considered. Here, we show that the solvent system used to attach collagen onto a hydrogel surface affects its surface distribution and organization, and this can modulate the responses of macrophages subsequently cultured on these surfaces in terms of their inflammatory activation and expression of adhesion and mechanosensitive molecules. Collagen was solubilized in either acetic acid (Col-AA) or N-(2-hydroxyethyl)piperazine-N'-ethanesulfonic acid (HEPES) (Col-HEP) solutions and conjugated onto soft and stiff polyacrylamide (PA) hydrogel surfaces. Bone marrow-derived macrophages cultured under standard conditions (pH 7.4) on the Col-HEP-derived surfaces exhibited stiffness-dependent inflammatory activation; in contrast, the macrophages cultured on Col-AA-derived surfaces expressed high levels of inflammatory cytokines and genes, irrespective of the hydrogel stiffness. Among the collagen receptors that were examined, leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) was the most highly expressed, and knockdown of the Lair-1 gene enhanced the secretion of inflammatory cytokines. We found that the collagen distribution was more homogeneous on Col-AA surfaces but formed aggregates on Col-HEP surfaces. The macrophages cultured on Col-AA PA hydrogels were more evenly spread, expressed higher levels of vinculin, and exerted higher traction forces compared to those of cells on Col-HEP. These macrophages on Col-AA also had higher nuclear-to-cytoplasmic ratios of yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), key molecules that control inflammation and sense substrate stiffness. Our results highlight that seemingly slight variations in substrate deposition for immunobiology studies can alter critical immune responses, and this is important to elucidate in the broader context of immunomodulatory biomaterial design.

Microbiomes in the context of developing sustainable intensified aquaculture.

With an ever-growing human population, the need for sustainable production of nutritional food sources has never been greater. Aquaculture is a key industry engaged in active development to increase production in line with this need while remaining sustainable in terms of environmental impact and promoting good welfare and health in farmed species. Microbiomes fundamentally underpin animal health, being a key part of their digestive, metabolic and defense systems, in the latter case protecting against opportunistic pathogens in the environment. The potential to manipulate the microbiome to the advantage of enhancing health, welfare and production is an intriguing prospect that has gained considerable traction in recent years. In this review we first set out what is known about the role of the microbiome in aquaculture production systems across the phylogenetic spectrum of cultured animals, from invertebrates to finfish. With a view to reducing environmental footprint and tightening biological and physical control, investment in "closed" aquaculture systems is on the rise, but little is known about how the microbial systems of these closed systems affect the health of cultured organisms. Through comparisons of the microbiomes and their dynamics across phylogenetically distinct animals and different aquaculture systems, we focus on microbial communities in terms of their functionality in order to identify what features within these microbiomes need to be harnessed for optimizing healthy intensified production in support of a sustainable future for aquaculture.

Histopathological survey of putative parasites and pathogens in non-native slipper limpets Crepidula fornicata.

Two populations of the invasive slipper limpet Crepidula fornicata were sampled in Swansea Bay and Milford Haven, Wales, UK, to determine the presence of putative pathogens and parasites known to affect co-located commercially important shellfish (e.g. oysters). A multi-resource screen, including molecular and histological diagnoses, was used to assess 1800 individuals over 12 mo for microparasites, notably haplosporidians, microsporidians and paramyxids. Although initial PCR-based methods suggested the presence of these microparasites, there was no evidence of infection when assessed histologically, or when all PCR amplicons (n = 294) were sequenced. Whole tissue histology of 305 individuals revealed turbellarians in the lumen of the alimentary canal, in addition to unusual cells of unknown origin in the epithelial lining. In total, 6% of C. fornicata screened histologically harboured turbellarians, and approximately 33% contained the abnormal cells-so named due to their altered cytoplasm and condensed chromatin. A small number of limpets (~1%) also had pathologies in the digestive gland including tubule necrosis, haemocytic infiltration and sloughed cells in the tubule lumen. Overall, these data suggest that C. fornicata are not susceptible to substantive infections by microparasites outside of their native range, which may contribute in part to their invasion success.

Extracellular vesicle signatures and protein citrullination are modified in shore crabs (Carcinus maenas) infected with Hematodinium sp.

Epizootiologists recurrently encounter symbionts and pathobionts in the haemolymph (blood equivalent) of shellfish. One such group is the dinoflagellate genus Hematodinium, which contains several species that cause debilitating disease in decapod crustaceans. The shore crab Carcinus maenas acts as a mobile reservoir of microparasites, including Hematodinium sp., thereby posing a risk to other co-located commercially important species, e.g. velvet crabs (Necora puber). Despite the widespread prevalence and documented seasonality of Hematodinium infection dynamics, there is a knowledge gap regarding host-pathogen antibiosis, namely, how Hematodinium avoids the host's immune defences. Herein, we interrogated the haemolymph of Hematodinium-positive and Hematodinium-negative crabs for extracellular vesicle (EV) profiles (a proxy for cellular communication), alongside proteomic signatures for post-translational citrullination/deimination performed by arginine deiminases, which can infer a pathologic state. Circulating EV numbers in parasitized crab haemolymph were reduced significantly, accompanied by smaller EV modal size profiles (albeit non-significantly) when compared to Hematodinium-negative controls. Differences were observed for citrullinated/deiminated target proteins in the haemolymph between the parasitized and control crabs, with fewer hits identified overall in the former. Three deiminated proteins specific to parasitized crab haemolymph were actin, Down syndrome cell adhesion molecule (DSCAM), and nitric oxide synthase - factors that contribute to innate immunity. We report, for the first time, Hematodinium sp. could interfere with EV biogenesis, and that protein deimination is a putative mechanism of immune-modulation in crustacean-Hematodinium interactions.

Shell disease syndromes of decapod crustaceans.

The term shell disease subsumes a number of debilitating conditions affecting the outer integument (the carapace) of decapod crustaceans, such as lobsters and crabs. Herein, we seek to find commonality in the aetiology and pathology of such conditions, and those cases that result in the progressive erosion of the cuticle through to the visceral tissues by a cocktail of microbial-derived enzymes including lipases, proteases and chitinases. Aquimarina spp. are involved in shell disease in many different crustaceans across a wide geographical area, but the overall view is that the condition is polymicrobial in nature leading to dysbiosis within the microbial consortium of the damaged cuticle. The role of environment, decapod behaviour and physiology in triggering this disease is also reviewed. Finally, we provide a conceptual model for disease aetiology and suggest several avenues for future research that could improve our understanding of how such factors trigger, or exacerbate, this condition.

Invasive slipper limpets Crepidula fornicata are hosts for sterilizing digenean parasites.

Invasion and spread of alien species can drive ecosystem changes, such as, the dynamics of infectious diseases. The non-native, marine gastropod Crepidula fornicata has become established across European coastlines over the last century, but there remains little insight into its disease carrying capacity and potential role as a source/sink of parasites. To address this knowledge gap, we surveyed limpets from two sites in South Wales, UK for signatures of disease/pathology using polymerase chain reaction-based methods (haemolymph) and histology (solid tissue). We encountered trematode-like parasites in ~1% individuals (5 out of 462). Three limpets displayed gross damage in the gonad, i.e. castration, and encysted metacercariae were found in the muscle of two other individuals. On the basis of 28S rDNA and internal transcribed spacer 2 genomic targets, we identified the gonad-infecting trematodes as members of the family Microphallidae ­ putative novel species related to the genus Longiductotrema. Earlier reports suggest that C. fornicata is not a host for trematode parasites in either its native or alien range but may act as a sink due to its filter feeding lifestyle. We provide clear evidence that C. fornicata is parasitized by at least one trematode species at two sites in Wales, UK, and likely act as a spillback or accidental host among native littorinids.

Hematodinium sp. infection does not drive collateral disease contraction in a crustacean host.

Host, pathogen, and environment are determinants of the disease triangle, the latter being a key driver of disease outcomes and persistence within a community. The dinoflagellate genus Hematodinium is detrimental to crustaceans globally - considered to suppress the innate defences of hosts, making them more susceptible to co-infections. Evidence supporting immune suppression is largely anecdotal and sourced from diffuse accounts of compromised decapods. We used a population of shore crabs (Carcinus maenas), where Hematodinium sp. is endemic, to determine the extent of collateral infections across two distinct environments (open-water, semi-closed dock). Using a multi-resource approach (PCR, histology, haematology, population genetics, eDNA), we identified 162 Hematodinium-positive crabs and size/sex-matched these to 162 Hematodinium-free crabs out of 1191 analysed. Crabs were interrogated for known additional disease-causing agents; haplosporidians, microsporidians, mikrocytids, Vibrio spp., fungi, Sacculina, trematodes, and haemolymph bacterial loads. We found no significant differences in occurrence, severity, or composition of collateral infections between Hematodinium-positive and Hematodinium-free crabs at either site, but crucially, we recorded site-restricted blends of pathogens. We found no gross signs of host cell immune reactivity towards Hematodinium in the presence or absence of other pathogens. We contend Hematodinium sp. is not the proximal driver of co-infections in shore crabs, which suggests an evolutionary drive towards latency in this environmentally plastic host.

The diarrhetic shellfish-poisoning toxin, okadaic acid, provokes gastropathy, dysbiosis and susceptibility to bacterial infection in a non-rodent bioassay, Galleria mellonella.

Diarrhetic shellfish-poisoning (DSP) toxins such as okadaic acid and dinophysistoxins harm the human gastrointestinal tract, and therefore, their levels are regulated to an upper limit of 160 µg per kg tissue to protect consumers. Rodents are used routinely for risk assessment and studies concerning mechanisms of toxicity, but there is a general move toward reducing and replacing vertebrates for these bioassays. We have adopted insect larvae of the wax moth Galleria mellonella as a surrogate toxicology model. We treated larvae with environmentally relevant doses of okadaic acid (80-400 µg/kg) via intrahaemocoelic injection or gavage to determine marine toxin-related health decline: (1) whether pre-exposure to a sub-lethal dose of toxin (80 µg/kg) enhances susceptibility to bacterial infection, or (2) alters tissue pathology and bacterial community (microbiome) composition of the midgut. A sub-lethal dose of okadaic acid (80 µg/kg) followed 24 h later by bacterial inoculation (2 × 105 Escherichia coli) reduced larval survival levels to 47%, when compared to toxin (90%) or microbial challenge (73%) alone. Histological analysis of the midgut depicted varying levels of tissue disruption, including nuclear aberrations associated with cell death (karyorrhexis, pyknosis), loss of organ architecture, and gross epithelial displacement into the lumen. Moreover, okadaic acid presence in the midgut coincided with a shift in the resident bacterial population over time in that substantial reductions in diversity (Shannon) and richness (Chao-1) indices were observed at 240 µg toxin per kg. Okadaic acid-induced deterioration of the insect alimentary canal resembles those changes reported for rodent bioassays.

Towards a Bio-Inspired Real-Time Neuromorphic Cerebellum.

This work presents the first simulation of a large-scale, bio-physically constrained cerebellum model performed on neuromorphic hardware. A model containing 97,000 neurons and 4.2 million synapses is simulated on the SpiNNaker neuromorphic system. Results are validated against a baseline simulation of the same model executed with NEST, a popular spiking neural network simulator using generic computational resources and double precision floating point arithmetic. Individual cell and network-level spiking activity is validated in terms of average spike rates, relative lead or lag of spike times, and membrane potential dynamics of individual neurons, and SpiNNaker is shown to produce results in agreement with NEST. Once validated, the model is used to investigate how to accelerate the simulation speed of the network on the SpiNNaker system, with the future goal of creating a real-time neuromorphic cerebellum. Through detailed communication profiling, peak network activity is identified as one of the main challenges for simulation speed-up. Propagation of spiking activity through the network is measured, and will inform the future development of accelerated execution strategies for cerebellum models on neuromorphic hardware. The large ratio of granule cells to other cell types in the model results in high levels of activity converging onto few cells, with those cells having relatively larger time costs associated with the processing of communication. Organizing cells on SpiNNaker in accordance with their spatial position is shown to reduce the peak communication load by 41%. It is hoped that these insights, together with alternative parallelization strategies, will pave the way for real-time execution of large-scale, bio-physically constrained cerebellum models on SpiNNaker. This in turn will enable exploration of cerebellum-inspired controllers for neurorobotic applications, and execution of extended duration simulations over timescales that would currently be prohibitive using conventional computational platforms.

Preclinical neurorehabilitation with environmental enrichment confers cognitive and histological benefits in a model of pediatric asphyxial cardiac arrest.

Pediatric asphyxial cardiac arrest (ACA) often leaves children with physical, cognitive, and emotional disabilities that affect overall quality of life, yet rehabilitation is neither routinely nor systematically provided. Environmental enrichment (EE) is considered a preclinical model of neurorehabilitation and thus we sought to investigate its efficacy in our established model of pediatric ACA. Male Sprague-Dawley rat pups (post-natal day 16-18) were randomly assigned to ACA (9.5 min) or Sham injury. After resuscitation, the rats were assigned to 21 days of EE or standard (STD) housing during which time motor, cognitive, and anxiety-like (i.e., affective) outcomes were assessed. Hippocampal CA1 cells were quantified on post-operative day-22. Both ACA + STD and ACA + EE performed worse on beam-balance vs. Sham controls (p < 0.05) and did not differ from one another overall (p > 0.05); however, a single day analysis on the last day of testing revealed that the ACA + EE group performed better than the ACA + STD group (p < 0.05) and did not differ from the Sham controls (p > 0.05). Both Sham groups performed better than ACA + STD (p < 0.05) but did not differ from ACA + EE (p > 0.05) in the open field test. Spatial learning and declarative memory were improved and CA1 neuronal loss was attenuated in the ACA + EE vs. ACA + STD group (p < 0.05). Collectively, the data suggest that providing rehabilitation after pediatric ACA can reduce histopathology and improve motor and cognitive ability.

Effects of Surface-Bound Collagen-Mimetic Peptides on Macrophage Uptake and Immunomodulation.

The interaction between collagen/collagen-like peptides and the commonly expressed immune cell receptor LAIR-1 (leukocyte-associated immunoglobulin-like receptor-1) regulates and directs immune responses throughout the body. Understanding and designing these interactions within the context of biomaterials could advance the development of materials used in medical applications. In this study, we investigate the immunomodulatory effects of biomaterials engineered to display a human collagen III-derived ligand peptide (LAIR1-LP) that targets LAIR-1. Specifically, we examine the effects of LAIR1-LP functionalized surfaces on uptake of polymeric particles and cell debris by macrophages polarized toward inflammatory or healing phenotypes. We observed that culture of macrophages on LAIR1-LP functionalized surfaces increased their uptake of PLGA micro- and nano-particles, as well as apoptotic fibroblasts, while reducing their secretion of TNFα in response to LPS/IFNγ pro-inflammatory stimulation, when compared to cells seeded on control surfaces. To investigate the role of LAIR-1 in the observed LAIR1-LP-induced effects, we used siRNA to knock down LAIR-1 expression and found that cells lacking LAIR-1 exhibited enhanced particle uptake on LAIR1-LP and control surfaces. Furthermore, analysis of gene expression showed that LAIR-1 knockdown led to increase expression of other receptors involved in cell uptake, including CD-36, SRA-1, and beta-2 integrin. Together, our study suggests that LAIR1-LP enhances macrophage uptake potentially through interactions with collagen-domain binding surface receptors, and inhibits inflammation through interaction with LAIR-1.

Mycosis is a Disease State Encountered Rarely in Shore Crabs, Carcinus maenas.

There is a paucity of knowledge regarding the diversity and impact(s) of disease-causing fungi in marine animals, especially shellfish. In efforts to address this knowledge gap for the shore crab Carcinus maenas, a year-long disease screen was carried out across two sites in Swansea Bay (Wales, UK) with a view to characterising putative fungal infections. Crabs were sampled between November 2017 and October 2018, and screened systematically for disease signatures using haemolymph (blood) preparations, targeted PCR and tissue histopathology. Strikingly, mycosis was confirmed in ~0.4% of total crabs tested (n = 1191) and restricted to one location only (Mumbles Pier). Clinical infections were observed in four out of four infected crabs. In these animals, the gills and hepatopancreas were congested with fungal morphotypes. In addition, some evidence indicates haemocyte (immune cell) reactivity toward the fungi. Phylogenetic placement of the partial internal transcribed spacer (ITS1) gene regions amplified from three mycotic crabs revealed the causative agent to be related to hypocrealean fungi, thereby representing a novel species.

Diagnosis and prevalence of two new species of haplosporidians infecting shore crabs Carcinus maenas: Haplosporidium carcini n. sp., and H. cranc n. sp.

This study provides a morphological and phylogenetic characterization of two novel species of the order Haplosporida (Haplosporidium carcini n. sp., and H. cranc n. sp.) infecting the common shore crab Carcinus maenas collected at one location in Swansea Bay, South Wales, UK. Both parasites were observed in the haemolymph, gills and hepatopancreas. The prevalence of clinical infections (i.e. parasites seen directly in fresh haemolymph preparations) was low, at ~1%, whereas subclinical levels, detected by polymerase chain reaction, were slightly higher at ~2%. Although no spores were found in any of the infected crabs examined histologically (n = 334), the morphology of monokaryotic and dikaryotic unicellular stages of the parasites enabled differentiation between the two new species. Phylogenetic analyses of the new species based on the small subunit (SSU) rDNA gene placed H. cranc in a clade of otherwise uncharacterized environmental sequences from marine samples, and H. carcini in a clade with other crustacean-associated lineages.

Laccase and catecholoxidase activities contribute to innate immunity in slipper limpets, Crepidula fornicata.

The slipper limpet Crepidula fornicata is an invasive, non-native, marine species found throughout the coastal waters of southern England and Wales, UK. These limpets are considered to blight commercial shellfish banks, notably oysters, yet little is known about their disease-carrying capacity or their immunobiology. To address the latter, we isolated haemolymph (blood) from limpets and tested for the presence of the immune-enzyme phenoloxidase. Invertebrate phenoloxidases produce melanic polymers from simple phenolic substrates, which are deployed in the presence of pathogens because of their potent microbicidal and microbiostatic properties. We used a series of established substrates (e.g., tyrosine, hydroquinone) and inhibitors (e.g., 4-hexylresorcinol, benzoic acid) to target three distinct enzymes: laccase (para-diphenoloxidase), catecholoxidase (ortho-diphenoloxidase) and tyrosinase (monophenoloxidase). We confirmed laccase and catecholoxidase activities and characterised their kinetic properties across temperature and pH gradients (5-70 °C and 5-10, respectively). Crucially, we demonstrated that products derived from such laccase and catecholoxidase activities reduced significantly the numbers of colony-forming units of both Gram-positive and Gram-negative bacteria in vitro. We further screened limpet tissues for signs of melanin using wax histology, and found cells replete with eumelanin-like pigments and lipofuscin in the digestive gland, connective tissues, barrier epithelia and gills. Our data represent the first account of enzyme-based antibacterial defences, notably laccase, in C. fornicata.

Prevalence and histopathology of the parasitic barnacle, Sacculina carcini in shore crabs, Carcinus maenas.

Sacculina carcini is a common parasite of the European shore crab, Carcinus maenas. Following successful penetration of the host, numerous rootlets are formed that permeate through the hosts' tissues. Ultimately, these form an externa that houses the developing nauplii larvae of the parasite. Most studies have quantified levels of infection by counting the presence of reproductive externae and their breakdown structures, called scars. However, the diagnosis of the disease based only on external features may lead to underreporting the prevalence of the parasite. In the current study, we examined the presence and severity of S. carcini in C. maenas (n = 221) in the Prince of Wales Dock, South Wales, U.K. using a range of diagnostic approaches to give an accurate representation of temporal dynamics of infection. Parasitized crabs were found with a mean prevalence of 24% as determined by histological examination of the hepatopancreas. However, the prevalence of S. carcini based on the presence of externae and scars was only 6.3% and 1.8%, respectively. Overall, parasitism was associated with smaller crabs, crabs later in the moulting cycle that were orange in colour (as opposed to green or yellow), and those with a higher number of bacteria in the haemolymph. Interestingly, only 7.5% of infected crabs showed evidence of distinct host (cellular) response to the presence of rootlets in the hepatopancreas.

Real-time cortical simulation on neuromorphic hardware.

Real-time simulation of a large-scale biologically representative spiking neural network is presented, through the use of a heterogeneous parallelization scheme and SpiNNaker neuromorphic hardware. A published cortical microcircuit model is used as a benchmark test case, representing ≈1 mm2 of early sensory cortex, containing 77 k neurons and 0.3 billion synapses. This is the first hard real-time simulation of this model, with 10 s of biological simulation time executed in 10 s wall-clock time. This surpasses best-published efforts on HPC neural simulators (3 × slowdown) and GPUs running optimized spiking neural network (SNN) libraries (2 × slowdown). Furthermore, the presented approach indicates that real-time processing can be maintained with increasing SNN size, breaking the communication barrier incurred by traditional computing machinery. Model results are compared to an established HPC simulator baseline to verify simulation correctness, comparing well across a range of statistical measures. Energy to solution and energy per synaptic event are also reported, demonstrating that the relatively low-tech SpiNNaker processors achieve a 10 × reduction in energy relative to modern HPC systems, and comparable energy consumption to modern GPUs. Finally, system robustness is demonstrated through multiple 12 h simulations of the cortical microcircuit, each simulating 12 h of biological time, and demonstrating the potential of neuromorphic hardware as a neuroscience research tool for studying complex spiking neural networks over extended time periods. This article is part of the theme issue 'Harmonizing energy-autonomous computing and intelligence'.

Host Range of the Mikrocytid Parasite Paramikrocytos canceri in Decapod Crustaceans.

Mikrocytids are a widespread but rather neglected group of parasites of aquatic invertebrates. One such parasite is Paramikrocytos canceri-discovered to infect the antennal gland of the juvenile edible crab, Cancer pagurus, taken from several intertidal sites across the United Kingdom. To determine if this parasite is also present in other species of decapod crustaceans, we surveyed crabs (n = 330) across two contrasting sites in Pembrokeshire (UK). Using a histopathological approach, P. canceri infection was confirmed in variable numbers of edible crabs from both survey sites, 7%-44%. No measurable signs of infection were encountered in four other co-located species, including European shore crabs (Carcinus maenas), Montagu's crabs (Xantho hydrophilus), velvet swimming crabs (Necora puber) and broad-clawed porcelain crabs (Porcellana platycheles). These data imply that P. canceri has a more limited host range than suggested by molecular diagnosis alone.

Spatial and temporal disease dynamics of the parasite Hematodinium sp. in shore crabs, Carcinus maenas.

BACKGROUND: The parasitic dinoflagellates of the genus Hematodinium represent the causative agent of so-called bitter or pink crab disease in a broad range of shellfish taxa. Outbreaks of Hematodinium-associated disease can devastate local fishing and aquaculture efforts. The goal of our study was to examine the potential role of the common shore (green) crab Carcinus maenas as a reservoir for Hematodinium. Carcinus maenas is native to all shores of the UK and Ireland and the North East Atlantic but has been introduced to, and subsequently invaded waters of, the USA, South Africa and Australia. This species is notable for its capacity to harbour a range of micro- and macro-parasites, and therefore may act as a vector for disease transfer. METHODS: Over a 12-month period, we interrogated 1191 crabs across two distinct locations (intertidal pier, semi-closed dock) in Swansea Bay (Wales, UK) for the presence and severity of Hematodinium in the haemolymph, gills, hepatopancreas and surrounding waters (eDNA) using PCR-based methods, haemolymph preparations and histopathology. RESULTS: Overall, 13.6% were Hematodinium-positive via PCR and confirmed via tissue examination. Only a small difference was observed between locations with 14.4% and 12.8% infected crabs in the Dock and Pier, respectively. Binomial logistic regression models revealed seasonality (P < 0.002) and sex (P < 0.001) to be significant factors in Hematodinium detection with peak infection recorded in spring (March to May). Male crabs overall were more likely to be infected. Phylogenetic analyses of the partial ITS and 18S rRNA gene regions of Hematodinium amplified from crabs determined the causative agent to be the host generalist Hematodinium sp., which blights several valuable crustaceans in the UK alone, including edible crabs (Cancer pagurus) and langoustines (Nephrops norvegicus). CONCLUSIONS: Shore crabs were infected with the host generalist parasite Hematodinium sp. in each location tested, thereby enabling the parasite to persist in an environment shared with commercially important shellfish.

Indomethacin-induced gut damage in a surrogate insect model, Galleria mellonella.

Indomethacin is a non-steroidal anti-inflammatory drug that causes gastric ulceration and increased 'leakiness' in rat models, and is used routinely as a toxicology assay to screen novel compounds for repair and restitution properties. We set out to establish conditions for indomethacin-induced gut damage in wax-moth (Galleria mellonella) larvae with a view to reducing the need for rodents in such experimentation. We administered indomethacin (0.5-7.5 µg/larva; 2-30 mg/kg) to G. mellonella via intrahaemocoelic injection and gavage (force-feeding) and monitored survival and development, blood cell (haemocyte) numbers, and changes in gut permeability. Increased levels of gut leakiness were observed within the first 4- to 24 h by tracking fluorescent microspheres in the faeces and haemolymph (blood equivalent). Additionally, we recorded varying levels of tissue damage in histological sections of the insect midgut, including epithelial sloughing and cell necrosis. Degeneration of the midgut was accompanied by significant increases in detoxification-associated activities (superoxide dismutase and glutathione-S-transferase). Herein, we present the first evidence that G. mellonella larvae force-fed indomethacin display broad symptoms of gastric damage similar to their rodent counterparts.

SpiNNTools: The Execution Engine for the SpiNNaker Platform.

SpiNNaker is a massively parallel distributed architecture primarily focused on real time simulation of spiking neural networks. The largest realization of the architecture consists of one million general purpose processors, making it the largest neuromorphic computing platform in the world at the present time. Utilizing these processors efficiently requires expert knowledge of the architecture to generate executable code and to harness the potential of the unique inter-processor communications infra-structure that lies at the heart of the SpiNNaker architecture. This work introduces a software suite called SpiNNTools that can map a computational problem described as a graph into the required set of executables, application data and routing information necessary for simulation on this novel machine. The SpiNNaker architecture is highly scalable, giving rise to unique challenges in mapping the problem to the machines resources, loading the generated files to the machine and subsequently retrieving the results of simulation. In this paper we describe these challenges in detail and the solutions implemented.