Methods for one-photon fluorescent imaging of calcium dynamics can capture the activity of hundreds of neurons across large fields of view at a low equipment complexity and cost. In contrast to ...two-photon methods, however, one-photon methods suffer from higher levels of crosstalk from neuropil, resulting in a decreased signal-to-noise ratio and artifactual correlations of neural activity. We address this problem by engineering cell-body-targeted variants of the fluorescent calcium indicators GCaMP6f and GCaMP7f. We screened fusions of GCaMP to natural, as well as artificial, peptides and identified fusions that localized GCaMP to within 50 μm of the cell body of neurons in mice and larval zebrafish. One-photon imaging of soma-targeted GCaMP in dense neural circuits reported fewer artifactual spikes from neuropil, an increased signal-to-noise ratio, and decreased artifactual correlation across neurons. Thus, soma-targeting of fluorescent calcium indicators facilitates usage of simple, powerful, one-photon methods for imaging neural calcium dynamics.
•One-photon calcium imaging of brain activity can suffer from neuropil crosstalk•Targeting GCaMPs to the cell body reduces neuropil crosstalk•One-photon imaging of somatic GCaMP reduces artifactual spikes and correlations•Somatic GCaMPs can be used in multiple species, such as mice and zebrafish
One-photon fluorescent imaging of calcium signals can capture the activity of hundreds of neurons across large fields of view but suffers from crosstalk from neuropil. Shemesh et al. engineer cell-body-targeted variants of fluorescent calcium indicators and show in mice and zebrafish that artifactual spikes and correlations are greatly reduced.
In the present work, an experimental study is presented aimed at assessing the chronic toxicity of three imidazole-based ionic liquids, i.e. imidazole (IM), 1-methylimidazole (1MIM), ...1-ethyl-3-methyl-imidazolium chloride (1E3MIM), and 1-butyl-3-methyl-imidazolium chloride (1B3MIM), generally considered as environmentally friendly surrogates of traditional industrial solvents. In this study Daphnia magna was used as test organism due to its wide application in the ecotoxicological literature of ionic liquids, monitoring both the cumulative survival of exposed organisms, and their reproductive parameters. The intracellular oxidative stress of daphnids was also assessed through the determination of Reactive Oxygen Species (ROS) and Catalase activity (CAT). The chronic toxicity of their oxidized by-products (BPs), generated by advanced oxidation treatment with UV254/H2O2, was finally evaluated. Four generations of BPs were considered, each formed at reaction times higher than those required for the complete removal of the parent compounds. Results indicate that IM and 1MIM have a moderate chronic toxicity, which mainly affects reproductive parameters. On the contrary, 1E3MIM and 1B3MIM showed significantly higher chronic toxicity effects resulting in a significant increase in the mortality of exposed organisms compared to the controls. UV/H2O2 treatment of the compounds did not always reduce the observed effects, since the generated BPs have, in some cases, higher chronic toxicity than their corresponding parent compounds. Chronic toxic effects remained significant up to the fourth generation of BPs in the cases of 1E3MIM and 1B3MIM, whereas they were found to be negligible from the second generation of BPs in the case of IM and 1MIM. The results of oxidative stress measurements confirmed the previous findings, suggesting a potential risk for the aquatic ecosystem induced by the mentioned compounds and their BPs.
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•Ionic Liquids are Contaminants on Horizon with toxicity mechanism poorly understood UV-C/H2O2 are efficient treatment for their removal from aqueous matrices•Treated solutions showed residual toxicity due to the photo-generated byproducts.•Treated and untreated solutions affected survival and reproduction of Daphnia Magna.•Longer treatment times are required to reduce the chronic toxicity of the solutions.
It has been established that children with Autism Spectrum Disorders (ASD) are affected by oxidative stress, the origin of which is still under investigation. In the present work, we evaluated ...inflammatory and pro-oxidant soluble signature in non-syndromic ASD and age-matched typically developing (TD) control children.
We analyzed leukocyte gene expression of inflammatory cytokines and inflammation/oxidative-stress related molecules in 21 ASD and 20 TD children. Moreover, in another-comparable-group of non-syndromic ASD (N = 22) and TD (N = 21) children, we analyzed for the first time the protein expression of the four members of the antioxidant enzyme family of peroxiredoxins (Prx) in both erythrocyte membranes and in plasma.
The gene expression of IL6 and of HSP70i, a stress protein, was increased in ASD children. Moreover, gene expression of many inflammatory cytokines and inflammation/oxidative stress-related proteins correlated with clinical features, and appeared to be linked by a complex network of inter-correlations involving the Aryl Hydrocarbon Receptor signaling pathway. In addition, when the study of inter-correlations within the expression pattern of these molecules was extended to include the healthy subjects, the intrinsic physiological relationships of the inflammatory/oxidative stress network emerged. Plasma levels of Prx2 and Prx5 were remarkably increased in ASD compared to healthy controls, while no significant differences were found in red cell Prx levels.
Previous findings reported elevated inflammatory cytokines in the plasma of ASD children, without clearly pointing to the presence of neuro-inflammation. On the other hand, the finding of microglia activation in autoptic specimens was clearly suggesting the presence of neuro-inflammation in ASD. Given the role of peroxiredoxins in the protection of brain cells against oxidative stress, the whole of our results, using peripheral data collected in living patients, support the involvement of neuro-inflammation in ASD, and generate a rational for neuro-inflammation as a possible therapeutic target and for plasma Prx5 as a novel indicator of ASD severity.
The purpose of the present work is to provide a complete overview of possible direct/indirect implications on the quality of aquatic compartments due to the recent SARS-CoV-2 outbreak. With this aim, ...the environmental impacts are mainly related to i) the virus persistence in sewage and wastewaters, and ii) possible fate in aquatic compartments of drugs tested and administered to SARS-CoV-2 infected patients. Because SARS-CoV-2 spread is very recent, and there is a lack of specific studies on this strain, the virus persistence in wastewaters, the parameters influencing the persistence, as well as the detection methodologies are referenced to the general coronaviruses group. However, the present detailed report of up-to-date knowledge on this topic can provide a useful source for further studies focusing on more deepened investigations of SARS-CoV-2 behaviour in the environment. Such a perspective is significant not only for the control of virus diffusion but also represents a crucial point for the identification of produced alteration to the environmental quality.
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•Current COVID-19 spread has important implications on the aquatic compartments.•Coronavirus persistence in wastewater can lead to further infection diffusion route.•Drugs for COVID-19 therapy in wastewater can cause negative environmental impact.
Metal concentrations were measured in plants growing on heavily contaminated tailings from a mine active since about 1800 in San Luis Potosí (Mexico).
Viguiera dentata (Cav.) Spreng.,
Parthenium ...bipinnatifidum (Ort.) Rollins,
Flaveria angustifolia (Cav.) Pers.,
F. trinervia (Spreng.) C. Mohr. and
Sporobolus
indicus (L.) R. Br. were tolerant to high As, Cu, Pb and Zn concentrations. Of those,
S.
indicus excluded heavy metals from its shoots, while
P. bipinnatifidum and
F. angustifolia accumulated them.
V. dentata and
P. bipinnatifidum were accumulators of As, but not hyperaccumulators. It was found that
V. dentata,
P. bipinnatifidum,
F. angustifolia,
F. trinervia and
S.
indicus, could be used to vegetate soils contaminated with As, Cu, Pb and Zn.
Ambrosia
artemisifolia could be used to remediate soils contaminated with Zn,
S. amplexicaulis those with Cu and
F. angustifolia and
F. trinervia those with As, as they have a strong capacity to accumulate those metals.
Olive mill residues, due to their low biodegradability and high amounts of phytotoxic compounds, are difficult to treat by means of conventional biological processes. In recent years several ...pretreatments of these by-products have been developed to increase their anaerobic biodegradability and to exploit them for biogas production. However, these processes are often expensive and hard to carry out. In this paper an effective and easy-to-manage pretreatment, based on the use of hydrogen peroxide under alkaline conditions without the addition of catalysts, is proposed. Many experiments were carried out on wet olive mill wastes in order to evaluate the influence of pH and peroxide dosage on process performance. Polyphenols abatements of about 72% were observed. The kinetic analysis of experimental results allowed us to investigate the reaction mechanisms and to optimize the operating procedures. This permitted to reduce the peroxide dosage without the occurrence of a remarkable performance reduction. By means of batch digestion tests, conducted in a pilot scale plant without co-substrates addition, it was verified a negligible biogas production detectable on raw olive mill waste, while a COD reduction about of 77% and a high methane yield of approximately 0.328 LCH4/gCODremoved were obtained on pretreated waste.
•A process with H2O2 in alkaline conditions without catalysts it was developed.•Samples of wet olive mill waste produced by a two phase decanter have been treated.•The mechanisms and the reaction kinetics of oxidation process have been identified.•The process improves the anaerobic treatability of wet olive mill wastes.•A methane yield of 0.328 LCH4/gCODremoved was obtained on pre-treated waste.
Imidazole-based compounds are used as reagents for the manufacturing of other compounds including imidazolium-based ionic liquids, which have been recently proposed as a green alternative to ...conventional solvents. Since some imidazole-based compounds have been demonstrated to be harmful to aquatic organisms, the removal of imidazole, 1-methylimidazole, 1-ethyl-3-methyl-imidazolium chloride and 1-butyl-3-methyl-imidazolium chloride from aqueous solutions was attempted by biological oxidation, direct UV254 photolysis, and UV254/H2O2 process at pH 5.5 and 8.5. Results showed that UV254/H2O2 treatment is an effective tool for the removal of the selected compounds at both pHs. In fact, the kinetic constants of the reaction between the photogenerated HO radicals and the four target compounds, estimated by means of both numerical and competition kinetic method, range between 2.32·109 M−1 s−1 and 5.52 ·109 M−1 s−1. Moreover, an ecotoxicity assessment of the contaminated water before and after initial treatment without further processing was assessed by using two living aquatic organisms: Raphidocelis subcapitata and Daphnia magna. The results of this assessment not only corresponded closely to previous findings (in terms of EC50 values) reported in the literature, but also indicated that, in some cases, UV254/H2O2 oxidation by-products could be even more toxic than parent compounds.
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•UV/H2O2 process was used to remove imidazole-based compounds in aqueous solutions.•The kinetic constants for HO attack on imidazole and its derivatives were estimated.•The ecotoxicity evolution was monitored during the chemical process.•An ecotoxicity increase was observed during the treatment of alkylimidazolium salts.
Learning valence-based responses to favorable and unfavorable options requires judgments of the relative value of the options, a process necessary for species survival. We found, using engineered ...mice, that circuit connectivity and function of the striosome compartment of the striatum are critical for this type of learning. Calcium imaging during valence-based learning exhibited a selective correlation between learning and striosomal but not matrix signals. This striosomal activity encoded discrimination learning and was correlated with task engagement, which, in turn, could be regulated by chemogenetic excitation and inhibition. Striosomal function during discrimination learning was disturbed with aging and severely so in a mouse model of Huntington’s disease. Anatomical and functional connectivity of parvalbumin-positive, putative fast-spiking interneurons (FSIs) to striatal projection neurons was enhanced in striosomes compared with matrix in mice that learned. Computational modeling of these findings suggests that FSIs can modulate the striosomal signal-to-noise ratio, crucial for discrimination and learning.
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•Striosomal, not matrix, striatal activity is shaped with valence-based learning•Striosomal, not matrix, DREADD manipulation opposingly modulates task engagement•Striosome-selective circuit decline occurs during aging and in mouse model of HD•Interneuron-striosome connectivity modulates SNR, and this increases with learning
Friedman et al. find that specialized regions of the striatum, a key part of the brain’s movement and motivation control system, are essential for learning about the values of good and bad outcomes of decisions. The learning signals in striosomes scale according to subjective value and are vulnerable to decline with aging and in neurodegenerative disorders.
In light of recent studies suggesting that amphetamine (AMPH) increases electrically evoked dopamine release (DAo), we examined discrepancies between these findings and literature that has ...demonstrated AMPH-induced decreases in DAo. The current study has expanded the inventory of AMPH actions by defining two separate mechanisms of AMPH effects on DAo at high and low doses, one dopamine transporter (DAT) independent and one DAT dependent, respectively. AMPH concentrations were measured via microdialysis in rat nucleus accumbens after intraperitoneal injections of 1 and 10 mg/kg and yielded values of ∼10 and 200 nM, respectively. Subsequently, voltammetry in brain slices was used to examine the effects of low (10 nM), moderate (100 nM), and high (10 μM) concentrations of AMPH across a range of frequency stimulations (one pulse; five pulses, 20 Hz; 24 pulses, 60 Hz). We discovered biphasic, concentration-dependent effects in WT mice, in which AMPH increased DAo at low concentrations and decreased DAo at high concentrations across all stimulation types. However, in slices from DAT-KO mice, DAo was decreased by all concentrations of AMPH, demonstrating that AMPH-induced increases in DAo are DAT dependent, whereas the decreases at high concentrations are DAT independent. We propose that low AMPH concentrations are insufficient to disrupt vesicular sequestration, and therefore AMPH acts solely as a DAT inhibitor to increase DAo. When AMPH concentrations are high, the added mechanism of vesicular depletion leads to reduced DAo. The biphasic mechanisms observed here confirm and extend the traditional actions of AMPH, but do not support mechanisms involving increased exocytotic release.
Cerium (Ce, CeCl3) and Erbium (Er, ErCl3) are increasingly used in many electronic devices facilitating the alteration of their biogeochemical cycles (e.g. e-waste). Previous surveys stated that ...their environmental concentrations due to natural or anthropogenic events can reach up to 161 μg/L in ore mine effluent for Ce with a mean water concentration of 0.79 μg/L, and 11.9 μg/L for Er in ore mine effluents with a mean water concentration of 0.004 μg/L. Their potential effects onto aquatic organisms are still relatively unexplored. In this study, long-term multigenerational effects on Daphnia magna were assessed using various exposure times (3, 7, 14, and 21 days) in three generations (F0, F1 and F2). Each generation was exposed to environmental concentrations of Ce and Er (0.54 and 0.43 μg/L, respectively – mean values) and effects included organisms' size, parental reproduction, and survival, determination of reactive oxygen species (ROS), enzymatic activity (superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST)), gene expression of ATP-binding cassette (ABC) transporter, and uptake.
Results evidenced that chronic multi-generational exposure of daphnids to Ce and Er reduced survival, growth and reproduction, decreasing ROS, SOD and CAT from F0 to F2. Ce reduced the number of generated offsprings after each generation, while Er delayed the time of offsprings emergence, but not their number. ROS, SOD, CAT and GST evidenced that Er is slightly more toxic than Ce. Up- and downregulation of genes was limited, but Ce and Er activated the ABC transporters. Uptake of Ce and Er decreased through exposure time and generations.
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•Toxicity of Ce and Er to D. magna chronic multigenerational test was evaluated.•Long-term generational exposure evidenced toxic effects with uptake events.•Ce reduced generated offsprings in F0-2, while Er delayed offsprings emergence.•Ce and Er rendered organisms more susceptible to oxidative stress.•ATP binding cassette showed an uptake-ejection equilibrium for Ce and Er in F0-2.
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