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This article discusses the potential of Zebrafish (ZF) (Danio Rerio), as a model for epilepsy research. Epilepsy is a neurological disorder affecting both children and adults, and many aspects of this disease are still poorly understood. In vivo and in vitro models derived from rodents are the most widely used for studying both epilepsy pathophysiology and novel drug treatments. However, researchers have recently obtained several valuable insights into these two fields of investigation by studying ZF. Despite the relatively simple brain structure of these animals, researchers can collect large amounts of data in a much shorter period and at lower costs compared to classical rodent models. This is particularly useful when a large number of candidate antiseizure drugs need to be screened, and ethical issues are minimized. In ZF, seizures have been induced through a variety of chemoconvulsants, primarily pentylenetetrazol (PTZ), kainic acid (KA), and pilocarpine. Furthermore, ZF can be easily genetically modified to test specific aspects of monogenic forms of human epilepsy, as well as to discover potential convulsive phenotypes in monogenic mutants. The article reports on the state-of-the-art and potential new fields of application of ZF research, including its potential role in revealing epileptogenic mechanisms, rather than merely assessing iatrogenic acute seizure modulation. [ABSTRACT FROM AUTHOR]

Zebrafish are powerful animal models for understanding biological processes and the molecular mechanisms involved in different human diseases. Advanced optical techniques based on fluorescence microscopy have become the main imaging method to characterize the development of these organisms at the microscopic level. However, the need for fluorescence probes and the consequent high light doses required to excite fluorophores can affect the biological process under observation including modification of metabolic function or phototoxicity. Here, without using any labels, we propose an implementation of a Mueller-matrix polarimeter into a commercial optical scanning microscope to characterize the polarimetric transformation of zebrafish preserved at different embryonic developmental stages. By combining the full polarimetric measurements with statistical analysis of the Lu and Chipman mathematical decomposition, we demonstrate that it is possible to quantify the structural changes of the biological organization of fixed zebrafish embryos and larvae at the cellular scale. This convenient implementation, with low light intensity requirement and cheap price, coupled with the quantitative nature of Mueller-matrix formalism, can pave the way for a better understanding of developmental biology, in which label-free techniques become a standard tool to study organisms. [ABSTRACT FROM AUTHOR]

Passion fruit-like nano-architectures (NAs) are all-in-one platforms of increasing interest for the translation of metal nanoparticles into clinics. NAs are nature-inspired disassembling inorganic theranostics, which jointly combine most of the appealing behaviors of noble metal nanoparticles with their potential organism excretion. Despite their unique and promising properties, NAs in vivo interactions and potential adverse effects have not yet been investigated. In this study, we employ zebrafish (Danio Rerio) to assess the development toxicity of NAs as well as their uptake and bioaccumulation at different stages of growth. The evaluation of multiple endpoints related to the toxicity clearly indicates that NAs do not induce mortality, developmental defects, or alterations on the hatching rate and behavior of zebrafish. Moreover, the analysis of nanostructures uptake and biodistribution demonstrates that NAs are successfully internalized and present a specific localization. Overall, our results demonstrate that NAs are able to pass through the embryos chorion and accumulate in specific tissues, exhibiting an impressive biocompatibility. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials (CNMs) are increasingly employed in nanomedicine as carriers for intracellular transport of drugs, imaging probes, and therapeutics agents, thanks to their unique optical and physicochemical properties. However, a better understanding about the effects of CNMs on a vertebrate model at the whole animal level is required. In this study, we compare the toxicity of oxidized carbon nano-onions (oxi-CNOs), oxidized carbon nano-horns (oxi-CNHs) and graphene oxide (GO) in zebrafish (Danio rerio). We evaluate the possible effects of these nanomaterials on zebrafish development by assessing different end-points and exposure periods. [ABSTRACT FROM AUTHOR]

Abstract: This review re-evaluates the use of immunological probes to map enkephalinergic, dynorphinergic, and endorphinergic circuits in the CNS of lobe-finned fishes, ray-finned fishes, and cartilaginous fishes in light of the characterization of proenkephalin, prodynorphin, and POMC sequences from representatives of these groups of fish over the past 20years. The use of α-MSH specific antisera is a reliable method for detecting POMC immunopositive cell bodies and fibers. Since α-MSH and β-endorphin are co-localized in the same neurons, these studies also reveal the distribution of endorphinergic networks. Met-enkephalin specific antisera can be used to detect enkephalinergic circuits in the CNS of gnathostomes because of the ubiquitous presence of this pentapeptide in the proenkephalin sequences of gnathostomes. However, the use of leu-enkephalin specific antisera to detect enkephalinergic networks is more problematic. While this immunological probe is appropriate for analyzing enkephalinergic networks in mammals and perhaps teleosts, for the lungfishes and cartilaginous fishes this probe is more likely able to detect dynorphinergic circuits. In this regard, there is a need to re-examine dynorphinergic networks in non-mammalian gnathostomes by using species specific antisera directed against dynorphin end-products. [Copyright &y& Elsevier]

Abstract: PINK1 is a 581 amino acid protein with a serine/threonine kinase domain and an N-terminal mitochondrial targeting motif. The enzyme is expressed in the brain as well as in several tissues such as heart, skeletal muscle, liver, kidney, pancreas and testis. In the present study, we have investigated by Western blot analysis and immunohistochemistry the presence and distribution of PINK1 in the brain, eye and inner ear of mouse during embryonic development. In the brain we detected two PINK1 molecular isoforms of 55kDa and 66kDa. Immunoreactive perikarya first appeared at stage E15 in the diencephalon within the thalamus, the hypothalamus, the periventricular layers of the third ventricle and in the rhombencephalon at level of the pons. Subsequently, new PINK1-positive neurons were found in the midbrain within the floor and the periventricular layers of the ventral wall of the mesencephalic vesicle (stage E17) as well as in the neopallial cortex, the tegmentum of the midbrain and the periventricular region of the caudal part of the rhombencephalon (stage E19). At P0, PINK1-immunoreactive cells appeared in the striatum, the mantle layer and caudal part of the medulla oblongata and the cerebellum. The spatio-temporal expression of PINK1 and its heterogeneous distribution suggest that the enzyme might be involved in neuroregulatory processes during embryogenesis. In the eye, PINK1-immunoreactivity was found in the lens and in the cornea, whereas in the inner ear the enzyme was expressed in the ependymal and subependymal cells of the saccule and in the semicircular canals indicating that PINK1 plays a role in the development of these sensory organs. [Copyright &y& Elsevier]

Abstract: Mouse UBPy (mUBPy) belongs to the family of ubiquitin-specific processing proteases (UBPs). In this study we have investigated the expression of mUBPy in the brain and sensory organs of mouse at different embryonic stages (E9, E11, E13, E15, E17, E19) and during the postnatal stages P0, P1, P2, P4 and P5 using Western blot and immunohistochemistry. mUBPy-immunoreactive cell bodies first appeared at stage E11 in several brain regions, particularly in the walls surrounding the vesicles and the ventricles. Subsequently, at stage E13, new mUBPy-positive cells appeared in the corpus striatum, the caudate nucleus, the thalamus, the epithalamus, the hypothalamus and the pons. At E15 the mUBPy pattern was very similar to that observed at E13, whereas at stage E17 mUBPy-immunoreactivity significantly decreased and a high number of mUBPy-immunoreactive cells was found only to line the third ventricle and within the mantle layer of the fourth ventricle. At E19 and P0, no mUBPy-immunoreactive element was found in the brain. At the postnatal stages P2 and P5, mUBPy-positive cells were detected in all subdivisions of the brain, with high concentrations in several cortex regions. Double labeling with the mUBPy antiserum and antisera against specific cell markers showed that the enzyme is expressed both in neurons and astrocytes. Outside the brain, mUBPy was detected, from stage E11, in the eye, within the lens and the cornea, in the inner ear, at the level of the cochlear and vestibular systems and in the olfactory epithelium. The spatio-temporal expression of mUBPy suggests that the enzyme may be involved in neuroregulatory processes during embryogenesis. [Copyright &y& Elsevier]

Boron/nitrogen, co-doped, carbon nano-onions (BN-CNOs) have recently shown great promise as catalysts for the oxygen reduction reaction, due to the improved electronic properties imparted by the dopant atoms; however, the interactions of BN-CNOs with biological systems have not yet been explored. In this study, we examined the toxicological profiles of BN-CNOs and oxidized BN-CNOs (oxi-BN-CNOs) in vitro in both healthy and cancer cell lines, as well as on the embryonic stages of zebrafish (Danio rerio) in vivo. The cell viabilities of both cell lines cells were not affected after treatment with different concentrations of both doped CNO derivatives. On the other hand, the analysis of BN-CNOs and oxidized BN-CNO interactions with zebrafish embryos did not report any kind of perturbations, in agreement with the in vitro results. Our results show that both doped CNO derivatives possess a high biocompatibility and biosafety in cells and more complex systems. [ABSTRACT FROM AUTHOR]

The aim of this article is to highlight the potential role of the locus-coeruleus–noradrenergic (LC-NA) system in neurodevelopmental disorders (NdDs). The LC is the main brain noradrenergic nucleus, key in the regulation of arousal, attention, and stress response, and its early maturation and sensitivity to perinatal damage make it an interesting target for translational research. Clinical data shows the involvement of the LC-NA system in several NdDs, suggesting a pathogenetic role in the development of such disorders. In this context, a new neuroimaging tool, LC Magnetic Resonance Imaging (MRI), has been developed to visualize the LC in vivo and assess its integrity, which could be a valuable tool for exploring morphological alterations in NdD in vivo in humans. New animal models may be used to test the contribution of the LC-NA system to the pathogenic pathways of NdD and to evaluate the efficacy of NA-targeting drugs. In this narrative review, we provide an overview of how the LC-NA system may represent a common pathophysiological and pathogenic mechanism in NdD and a reliable target for symptomatic and disease-modifying drugs. Further research is needed to fully understand the interplay between the LC-NA system and NdD. [ABSTRACT FROM AUTHOR]

Plasmonic nanoparticles are increasingly employed in several fields, thanks to their unique, promising properties. In particular, these particles exhibit a surface plasmon resonance combined with outstanding absorption and scattering properties. They are also easy to synthesize and functionalize, making them ideal for nanotechnology applications. However, the physicochemical properties of these nanoparticles can make them potentially toxic, even if their bulk metallic forms are almost inert. In this review, we aim to provide a more comprehensive understanding of the potential adverse effects of plasmonic nanoparticles in zebrafish (Danio rerio) during both development and adulthood, focusing our attention on the most common materials used, i.e., gold and silver. [ABSTRACT FROM AUTHOR]

Graphene-like (GL) layers, a new graphene-related material (GRM), possess peculiar chemical, colloidal, optical and transport properties. Considering the very recent promising application of GL layers in biomedical and bioelectronic fields, it is of utmost importance to investigate the toxicological profile of these nanomaterials. This study represents an important first report of a complete in vivo toxicity assessment of GL layers on embryonic zebrafish (Danio rerio). Our results show that GL layers do not lead to any perturbations in the different biological parameters evaluated, indicating their good biocompatibility on a vertebrate model. The new insight into the biosafety of GL layers will expand their applications in nanomedicine. [ABSTRACT FROM AUTHOR]

Calcium carbonate nanoparticles (CaCO 3 NPs) derived from CO 2 are evaluated in terms of toxicological profile both in vitro (cells) and in vivo (zebrafish). The toxicity in cells is investigated as cell viability, while in zebrafish using different biological parameters (i.e. survival). • CaCO 3 NPs are purely cubic calcite with a narrow particle size distribution. • CaCO 3 NPs do not affect the cell viability of normal (NIH 3T3) and cancer (MCF7) cells. • High concentrations of CaCO 3 NPs exhibit no genotoxicity against NIH 3T3 and MCF7 cells. • CaCO 3 NPs have no developmental toxicity to zebrafish embryos. Calcium carbonate nanoparticles (CaCO 3 NPs) derived from CO 2 are promising materials for different industrial applications. It is imperative to understand their toxicological profile in biological systems as the human and environmental exposures to CaCO 3 NPs increases with growing production. Here, we analyse the cytotoxicity of CaCO 3 NPs synthesized from a CaO slurry on two cell lines, and in vivo on zebrafish (Danio Rerio). Our results demonstrate the CaCO 3 NPs in vitro safety as they do not cause cell death or genotoxicity. Moreover, zebrafish treated with CaCO 3 NPs develop without any abnormalities, confirming the safety and biocompatibility of this nanomaterial. [ABSTRACT FROM AUTHOR]

• The conjugate is effective in enhancing the solubility of CNOs in aqueous media. • CNO:HA-DMPE do not affect the cell viability of both cell lines tested. • CNO:HA-DMPE localize in cancer cells overexpressing CD44. • CNO:HA-DMPE present a high biocompatibility in zebrafish. • CNO:HA-DMPE accumulate in larvae in the digestive tract. Carbon nano-onions (CNOs) are promising materials for biomedical applications due to their low cytotoxicity and excellent biocompatibility. Supramolecular functionalization with biocompatible polymers is an effective strategy to develop engineered drug carriers for targeted delivery applications. In this study, we report the use of a hyaluronic acid-phospholipid (HA-DMPE) conjugate to target CD44 overexpressing cancer cells, while enhancing solubility of the nanoconstruct. Non-covalently functionalized CNOs with HA-DMPE show excellent in vitro cell viability in human breast carcinoma cells overexpressing CD44 and are uptaken to a greater extent compared to human ovarian carcinoma cells with an undetectable amount of CD44. In addition, they possess high in vivo biocompatibility in zebrafish (Danio Rerio) during the different stages of development and they prevalently localize in the digestive tract of the zebrafish larvae. [ABSTRACT FROM AUTHOR]

Plasmonic nanostructures capable of converting light to heat have found wide applications, thus giving rise to the field of thermoplasmonics. Among them, the use of gold-based plasmonic structures in near-infrared (NIR) spectral regions has catalyzed substantial research efforts due to the potential impact in clinical therapy applications. However, the photon scattering effect scaling with the square of the nanoparticle volume leads to high scattering and then low absorption efficiency. This limit has hindered the exploitation of gold nanoparticles, especially in NIR II regions above 1000 nm. Here, we make a step forward for overcoming this limitation by introducing hyperbolic metamaterial nanoparticles that are made of multi-layered gold/dielectric nanodisks and exhibit >70% absorption efficiency in the NIR II and III regions. Their high light-to-heat conversion is demonstrated by a much larger temperature increase than that of gold nanodisks with the same amount of gold. Efficient in vitro hyperthermia of living cells with negligible cytotoxicity shows the potential of our platform for versatile bio-medical applications. [ABSTRACT FROM AUTHOR]

Abstract: Stimulation emission depletion (STED) microscopy breaks the spatial resolution limit of conventional light microscopy while retaining its major advantages, such as working under physiological conditions. These properties make STED microscopy a perfect tool for investigating dynamic sub-cellular processes in living organisms. However, up to now, the massive dissemination of STED microscopy has been hindered by the complexity and cost of its implementation. Gated CW-STED (gCW-STED) substantially helps solve this problem without sacrificing spatial resolution. Here, we describe a versatile gCW-STED microscope able to speedily image the specimen, at a resolution below 50nm, with light intensities comparable to the more complicated all-pulsed STED system. We show this ability on calibration samples as well as on biological samples. [Copyright &y& Elsevier]

Hormonal changes in humans during spaceflight have been demonstrated but the underlying mechanisms are still unknown. To clarify this point thyroid and testis/epididymis, both regulated by anterior pituitary gland, have been analyzed on long-term space-exposed male C57BL/10 mice, either wild type or pleiotrophin transgenic, overexpressing osteoblast stimulating factor-1. Glands were submitted to morphological and functional analysis. In thyroids, volumetric ratios between thyrocytes and colloid were measured. cAMP production in 10-7M and 10-8M thyrotropin-treated samples was studied. Thyrotropin receptor and caveolin-1 were quantitized by immunoblotting and localized by immunofluorescence. In space-exposed animals, both basal and thyrotropin-stimulated cAMP production were always higher. Also, the structure of thyroid follicles appeared more organized, while thyrotropin receptor and caveolin-1 were overexpressed. Unlike the control samples, in the space samples thyrotropin receptor and caveolin-1 were both observed at the intracellular junctions, suggesting their interaction in specific cell membrane microdomains. In testes, immunofluorescent reaction for 3β- steroid dehydrogenase was performed and the relative expressions of hormone receptors and interleukin-1β were quantified by RT-PCR. Epididymal sperm number was counted. In space-exposed animals, the presence of 3β and 17β steroid dehydrogenase was reduced. Also, the expression of androgen and follicle stimulating hormone receptors increased while lutenizing hormone receptor levels were not affected. The interleukin 1 β expression was upregulated. The tubular architecture was altered and the sperm cell number was significantly reduced in spaceflight mouse epididymis (approx. 290% vs. laboratory and ground controls), indicating that the space environment may lead to degenerative changes in seminiferous tubules. Space-induced changes of structure and function of thyroid and testis/epididymis could be responsible for variations of hormone levels in human during space missions. More research, hopefully a reflight of MDS, would be needed to establish whether the space environment acts directly on the peripheral glands or induces changes in the hypotalamus-pituitary-glandular axis. [ABSTRACT FROM AUTHOR]