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IEEE Transactions on Neural Systems and... 2024Multielectrode arrays for interfacing with neurons are of great interest for a wide range of medical applications. However, current electrodes cause damage over time....
Multielectrode arrays for interfacing with neurons are of great interest for a wide range of medical applications. However, current electrodes cause damage over time. Ultra small carbon fibers help to address issues but controlling the electrode site geometry is difficult. Here we propose a methodology to create small, pointed fiber electrodes (SPFe). We compare the SPFe to previously made blowtorched fibers in characterization. The SPFe result in small site sizes [Formula: see text] with consistently sharp points (20.8 ± 7.64°). Additionally, these electrodes were able to record and/or stimulate neurons multiple animal models including rat cortex, mouse retina, Aplysia ganglia and octopus axial cord. In rat cortex, these electrodes recorded significantly higher peak amplitudes than the traditional blowtorched fibers. These SPFe may be applicable to a wide range of applications requiring a highly specific interface with individual neurons.
Topics: Mice; Rats; Animals; Carbon Fiber; Electrodes, Implanted; Electrodes; Neurons; Cerebral Cortex
PubMed: 38294928
DOI: 10.1109/TNSRE.2024.3360866 -
Biology Dec 2023The intercalibration of age readings represents a crucial step in the ageing procedure; the use of different sampling methods, structures, preparation techniques, and...
The intercalibration of age readings represents a crucial step in the ageing procedure; the use of different sampling methods, structures, preparation techniques, and ageing criteria can significantly affect age and growth data. This study evaluated the precision and accuracy of ageing for the most important North Atlantic (NA) and Mediterranean (M) ray species, , , , and , through exchange exercises carried out by readers from different laboratories. In addition, growth parameters were estimated from the obtained data. A total of 663 individual batoids were analysed. and samples were obtained from both the NA and the M, while vertebral centra of and were only available for the M. High reading variability was observed for all four evaluated species in terms of CV, APE, and PA. and showed relatively slow growth and the von Bertalanffy model with fixed and Gompertz's model were, respectively, the most precise models for each of these species. In , females had a faster growth rate compared to combined sexes. The vbt0p proved the most precise model for describing growth in this species, and no statistical differences were found between the NO and the M. For , the best-fitting model was the vbt0p for females and males in the NO and for females from the M, while the best-fitting model for males from the M and sexes combined for both areas was log.p. Distinct growth patterns were observed between the two study areas.
PubMed: 38248451
DOI: 10.3390/biology13010020 -
Journal of Agricultural and Food... Dec 2023Novel agrochemicals have been successfully developed using target-based drug design (TBDD). To discover a novel, efficient, and highly selective nicotinic insecticide...
Novel agrochemicals have been successfully developed using target-based drug design (TBDD). To discover a novel, efficient, and highly selective nicotinic insecticide candidate, we developed a unified pharmacological model using TBDD by studying the binding modes of 11 nicotinic acetylcholine receptor (nAChR) modulators with acetylcholine binding protein (AChBP) targets for the first time. This model was used to design and develop a series of 1,2,4-triazolone derivatives. Bioassays demonstrated excellent insecticidal activities against of compounds (LC = 4.95 mg/L) and (LC = 3.17 mg/L), and low toxicities to . Additionally, compound was stably bound to AChBP, which was consistent with the pharmacological model obtained via molecular docking and molecular dynamics simulations. Therefore, compound could be a potential lead candidate targeting nAChR. The explicit pharmacological model of nAChR modulators with -AChBP in this study may facilitate the future rational design of eco-friendly nicotinic insecticides.
Topics: Animals; Bees; Receptors, Nicotinic; Molecular Docking Simulation; Nicotine; Insecticides; Carrier Proteins
PubMed: 38050804
DOI: 10.1021/acs.jafc.3c04998 -
Integrated Environmental Assessment and... Jan 2024The second Fundão Dam Rupture Science Meeting was held in Ouro Preto, Minas Gerais, Brazil, on 21 and 22 September 2022. A total of 100 delegates attended the meeting,...
The second Fundão Dam Rupture Science Meeting was held in Ouro Preto, Minas Gerais, Brazil, on 21 and 22 September 2022. A total of 100 delegates attended the meeting, which featured high-quality oral presentations and posters over the two days and lively discussions of the science presented. The meeting resulted in nine papers being published in this special series. In the discussion, it was commented that the first meeting had been more a meeting of competitive perspectives but that the second meeting featured a more collaborative sharing of knowledge. Also, there had been substantial improvement in ways to deal with the lack of pre-event data and account for other stressors in the system, and as a result, stronger conclusions regarding the recovery rates of the system were able to be made. Importantly, there was no evidence for a feasible "time bomb" of a future catastrophic release of contaminants, but it was agreed that different scenarios continue to be researched. Integr Environ Assess Manag 2024;20:70-73. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
Topics: Ecotoxicology; Brazil; Environmental Monitoring
PubMed: 38037522
DOI: 10.1002/ieam.4863 -
Brain, Behavior and Evolution 2023Several evolutionary explanations have been proposed for why chronic pain is a major clinical problem. One is that some mechanisms important for driving chronic pain,... (Review)
Review
BACKGROUND
Several evolutionary explanations have been proposed for why chronic pain is a major clinical problem. One is that some mechanisms important for driving chronic pain, while maladaptive for modern humans, were adaptive because they enhanced survival. Evidence is reviewed for persistent nociceptor hyperactivity (PNH), known to promote chronic pain in rodents and humans, being an evolutionarily adaptive response to significant bodily injury, and primitive molecular mechanisms related to cellular injury and stress being exapted (co-opted or repurposed) to drive PNH and consequent pain.
SUMMARY
PNH in a snail (Aplysia californica), squid (Doryteuthis pealeii), fruit fly (Drosophila melanogaster), mice, rats, and humans has been documented as long-lasting enhancement of action potential discharge evoked by peripheral stimuli, and in some of these species as persistent extrinsically driven ongoing activity and/or intrinsic spontaneous activity (OA and SA, respectively). In mammals, OA and SA are often initiated within the protected nociceptor soma long after an inducing injury. Generation of OA or SA in nociceptor somata may be very rare in invertebrates, but prolonged afterdischarge in nociceptor somata readily occurs in sensitized Aplysia. Evidence for the adaptiveness of injury-induced PNH has come from observations of decreased survival of injured squid exposed to predators when PNH is blocked, from plausible survival benefits of chronic sensitization after severe injuries such as amputation, and from the functional coherence and intricacy of mammalian PNH mechanisms. Major contributions of cAMP-PKA signaling (with associated calcium signaling) to the maintenance of PNH both in mammals and molluscs suggest that this ancient stress signaling system was exapted early during the evolution of nociceptors to drive hyperactivity following bodily injury. Vertebrates have retained core cAMP-PKA signaling modules for PNH while adding new extracellular modulators (e.g., opioids) and cAMP-regulated ion channels (e.g., TRPV1 and Nav1.8 channels).
KEY MESSAGES
Evidence from multiple phyla indicates that PNH is a physiological adaptation that decreases the risk of attacks on injured animals. Core cAMP-PKA signaling modules make major contributions to the maintenance of PNH in molluscs and mammals. This conserved signaling has been linked to ancient cellular responses to stress, which may have been exapted in early nociceptors to drive protective hyperactivity that can persist while bodily functions recover after significant injury.
Topics: Humans; Animals; Rats; Mice; Nociceptors; Chronic Pain; Drosophila melanogaster; Adaptation, Physiological; Mammals
PubMed: 38035556
DOI: 10.1159/000535552 -
HardwareX Dec 2023The California sea hare () provides a powerful biomedical model system for studying aspects of neurological development and damage, behavior, aging, and hypoxia....
Untangling the Gordian Knot of sea hare egg masses: An integrated open-hardware system for standardized egg strand sizing and packaging for cryopreservation research and application.
The California sea hare () provides a powerful biomedical model system for studying aspects of neurological development and damage, behavior, aging, and hypoxia. encapsulate their zygotes within strands that result in tangled egg masses that greatly complicate culture and experimentation. The historical and current importance of for biomedical research and the mounting climate crisis necessitates protection of genetic resources. The goal of this work was to prototype open-hardware sizing, processing, and packaging devices for early life stages suitable for integration into a cryopreservation pathway. The Strand Centi-Sizer was a low-cost, fused filament fabrication 3-D printable device that increased experiment preparation efficiency and standardized the cutting of egg strands customizable to user needs. A downstream system of 3-D printed devices was also prototyped to address inefficiencies in handling of egg strand sections for processing and packaging into existing cryopreservation straw platforms. Time studies were conducted comparing manual methods (i.e., no specialized equipment) with open hardware to demonstrate utility of the devices and to encourage community members to design and prototype new devices to address recurrent and novel problems in other aquatic animals that produce egg strands. Improvements in design could further increase efficiency, standardization, and reproducibility, and extend the application of these devices to other research communities, such as shrimp or salamander spermatophores, sea anemone body part (e.g., pedal lacerate) cryopreservation, or study areas such as vitrification.
PubMed: 38020540
DOI: 10.1016/j.ohx.2023.e00476 -
Pharmaceuticals (Basel, Switzerland) Nov 2023Cancer is a major disease that threatens human health all over the world. Intervention and prevention in premalignant processes are successful ways to prevent cancer...
Cancer is a major disease that threatens human health all over the world. Intervention and prevention in premalignant processes are successful ways to prevent cancer from striking. On the other hand, the marine ecosystem is a treasure storehouse of promising bioactive metabolites. The use of such marine products can be optimized by selecting a suitable nanocarrier. Therefore, -obtusane, previously isolated from , was investigated for its potential anticancer effects toward cervical cancer through a series of in vitro assays in HeLa cells using the MTT assay method. Additionally, the sesquiterpene was encapsulated within a liposomal formulation (size = 130.8 ± 50.3, PDI = 0.462, zeta potential -12.3 ± 2.3), and the antiproliferative potential of -obtusane was investigated against the human cervical cancer cell line HeLa before and after encapsulation with liposomes. -obtusane exhibited a potent effect against the HeLa cell line, while the formulated molecule with liposomes increased the in vitro antiproliferative activity. Additionally, cell cycle arrest analysis, as well as the apoptosis assay, performed via FITC-Annexin-V/propidium iodide double staining (flow cytofluorimetry), were carried out. The pharmacological network enabled us to deliver further insights into the mechanism of -obtusane, suggesting that STAT3 might be targeted by the compound. Moreover, molecular docking showed a comparable binding score of the isolated compound towards the STAT3 SH2 domain. The targets possess an anticancer effect through the endometrial cancer pathway, regulation of DNA templated transcription, and nitric oxide synthase, as mentioned by the KEGG and ShinyGo 7.1 databases.
PubMed: 38004443
DOI: 10.3390/ph16111578 -
Scientific Reports Nov 2023The presynaptic release apparatus can be specialized to enable specific synaptic functions. Habituation is the diminishing of a physiological response to a frequently...
The presynaptic release apparatus can be specialized to enable specific synaptic functions. Habituation is the diminishing of a physiological response to a frequently repeated stimulus and in Aplysia, habituation to touch is mediated by a decrease in transmitter release from the sensory neurons that respond to touch even after modest rates of action potential firing. This synaptic depression is not common among Aplysia synaptic connections suggesting the presence of a release apparatus specialized for this depression. We found that specific splice forms of ApCa2, the calcium channel required for transmitter release, are preferentially used in sensory neurons, consistent with a specialized release apparatus. However, we were not able to find a specific ApCa2 splice uniquely required for synaptic depression. The C-terminus of ApCa2 alpha1 subunit retains conserved binding to Aplysia rab-3 interacting molecule (ApRIM) and ApRIM-binding protein (ApRBP) and the C-terminus is required for full synaptic expression of ApCa2. We also identified a splice form of ApRIM that did not interact with the ApCav2 alpha 1 subunit, but it was not preferentially used in sensory neurons.
Topics: Animals; Calcium Channels; Aplysia; Sensory Receptor Cells; Protein Isoforms; Action Potentials; Synaptic Transmission; Synapses; Calcium
PubMed: 37980443
DOI: 10.1038/s41598-023-47573-z -
Virology Jan 2024Two recent studies documented the genome of a novel, extremely large (35.9 kb), nidovirus in RNA sequence databases from the marine neural model Aplysia californica....
Two recent studies documented the genome of a novel, extremely large (35.9 kb), nidovirus in RNA sequence databases from the marine neural model Aplysia californica. The goal of the present study was to document the distribution and transcriptional dynamics of this virus, Aplysia abyssovirus 1 (AAbV), in maricultured and wild animals. We confirmed previous findings that AAbV RNA is widespread and reaches extraordinary levels in apparently healthy animals. Transmission electron microscopy identified viral replication factories in ciliated gill epithelial cells but not in neurons where viral RNA is most highly expressed. Viral transcripts do not exhibit evidence of discontinuous RNA synthesis as in coronaviruses but are consistent with production of a single leaderless subgenomic RNA, as in the Gill-associated virus of Penaeus monodon. Splicing patterns in chronically infected adults suggested high levels of defective genomes, possibly explaining the lack of obvious disease signs in high viral load animals.
Topics: Animals; Aplysia; Nidovirales; RNA, Viral; Microscopy, Electron, Transmission
PubMed: 37951086
DOI: 10.1016/j.virol.2023.109890 -
Frontiers in Behavioral Neuroscience 2023The transcription factor CCAAT/enhancer binding protein () is expressed as an immediate early gene in the cAMP responsive element binding protein (CREB) mediated gene...
The transcription factor CCAAT/enhancer binding protein () is expressed as an immediate early gene in the cAMP responsive element binding protein (CREB) mediated gene cascade, and it has essential functions in the synaptic consolidation of memory following a learning event. Synaptic consolidation primarily involves morphological changes at neuronal synapses, which are facilitated through the reorganization of the actin and microtubular cytoarchitecture of the cell. During early nervous system development, the transmembrane synaptic protein teneurin acts directly upon neuronal presynaptic microtubules and postsynaptic spectrin-based cytoskeletons to facilitate the creation of new synapses. It is reasonable to hypothesize that may also be linked to learning-induced synaptic changes and is a potential candidate to be a later gene expressed in the CREB-mediated gene cascade downstream of . To assess the role of and in learning and memory in the marine snail , young (age 7-8 months) and aged (age 13-15 months; aging stage AII) siblings of Aplysia were trained in an operant conditioning paradigm-learning food is inedible (LFI)-over 2 days, during which they learned to modify the feeding reflex. Aged had enhanced performance of the LFI task on the second day than younger siblings although far more aged animals were excluded from the analysis because of the initial failure in learning to recognize the inedible probe. After 2 days of training, mRNA and mRNA were quantified in selected neurons of the buccal ganglia, the locus of neural circuits in LFI. expression was elevated in aged compared to young siblings regardless of training. expression was significantly higher in untrained aged animals than in untrained young siblings but decreased in trained aged animals compared to untrained aged animals. Elevated levels of and mRNA before training may have contributed to the enhancement of LFI performance in the aged animals that successfully learned.
PubMed: 37936650
DOI: 10.3389/fnbeh.2023.1221794