Glutamate Elicits Therapeutic Responses in Light-Induced Sleep-Deprived Zebrafish, Danio rerio

Sleep deprivation disrupts most neurotransmitters, which can lead to adverse behavioural changes and other psychiatric illnesses. Many neurotransmitter systems, including dopamine (DA), serotonin (5-HT), norepinephrine (N.E.) and GABA, have been implicated in the pathophysiology of mood disorders. The precise significance of sleep deprivation (S.D.) changes in the neurotransmitter levels and the mechanism underlying behavioural alterations is unknown. According to research, sleep deprivation (S.D.) has a major effect on an individual’s quality of life and ability to perform essential physiological functions. As a result, we wanted to confirm the levels of neurotransmitters and behavioural modifications in zebrafish after 24, 48, and 72 hours of sleep deprivation and glutamate treatment on the sleep-deprived groups. The T-maze test was used to assess learning and memory alterations in zebrafish. We used the Novel Tank Test (NTT) and Light and Dark Test (LDT) to examine the anxiety-like behaviour. The spectrofluorimetric method was used to determine the quantities of DA, 5-HT, N.E. and GABA. From this study, it is evident that 72h sleep-deprived fish had a loss of learning and memory via T-maze test and also the anxiety levels were very high in the sleep-deprived group than the other groups. The groups that received glutamate after sleep deprivation showed betterment in the behavioural response. Also, the levels of neurotransmitters were increased in the glutamate treated groups than the sleep-deprived groups. Our findings indicate that sleep loss dramatically impairs behavioural responses and disrupts most neurotransmitter concentrations. When sleep-deprived fish were given glutamate, their behaviour and neurotransmitter levels were nearly identical to those of the control group. This study will have a greater impact on sleep deprivation therapy and pave the way for using the neurotransmitters as external therapeutic agents in treating sleep deprivation and other behavioural changes related to sleep deprivation.It has been suggested that zebrafish is an excellent testing subject for loss of sleep on cognition and that it may also be an efficient model for unravelling the pathways that underpin learning and memory formation.

Model tests of a 10 MW semi-submersible floating wind turbine under waves and wind using hybrid method to integrate the rotor thrust and moments

This paper describes the results of a wave tank test campaign of a 1/49 scaled SATH 10MW INNWIND floating platform. The Software-in-the-Loop (SiL) hybrid method was used to include the wind turbine thrust and the in-plane rotor moments My – Mz. Experimental results are compared with a numerical model developed in OpenFAST of the floating wind turbine. The tank test campaign was carried out in the scaled model tested at the Deep Ocean Basin from the Lir National Ocean TF at Cork, Ireland. This floating substructure design was adapted by Saitec to support the 10MW INNWIND wind turbine within the ARCWIND project with the aim of withstanding the environmental conditions of the European Atlantic Area region. CENER provided the wind turbine controller specially designed for the SATH 10MW configuration. A description of the experimental set up, force actuator configuration and the numeric aerodynamic parameters are provided in this work. The most relevant experimental results under wind and wave loading are showed in time series and frequency domain. The influence of the submerged geometry variations in the pitch natural frequency is discussed. The paper shows the simulation of a case with rated wind speed, where the tilted geometry for the computation of the hydrostatic and hydrodynamic properties of the submerged substructure is considered. This case provides a better agreement of the pitch natural frequency with the experiments, than a equivalent simulation using the undisplaced geometry mesh for the computation of the hydrodynamic and hydrostatic properties.

Social Stress Increases Anxiety-Like Behavior Equally in Male and Female Zebrafish

Zebrafish anxiety-like behavior was assessed in the novel tank test after the formation of dominant-subordinate hierarchies. Ten pairs of animals were subjected to dyadic interactions for 5 days, and compared with control animals. After this period, a clear dominance hierarchy was established across all dyads, irrespective of sex. Social status affected parameters of anxiety-like behavior in the novel tank test, with subordinate males and females displaying more bottom-dwelling, absolute turn angle, and freezing than dominant animals and controls. The results suggest that subordinate male and female zebrafish show higher anxiety-like behavior, which together with previous literature suggests that subordination stress is conserved across vertebrates.

Micronized curcumin causes hyperlocomotion in zebrafish larvae

Zebrafish larvae have been widely used in neuroscience and drug research and development. In the larval stage, zebrafish present a broad behavioral repertoire and physiological responses similar to adults. Curcumin (CUR), a major component of Curcuma longa L. (Zingiberaceae), has demonstrated the ability to modulate several neurobiological processes relevant to mental disorders in animal models. However, the low bioavailability of this compound can compromise its in vivo biological potential. Interestingly, it has been shown that micronization can increase the biological effects of several compounds. Thus, in this study, we compared the effects of acute exposure for 30 minutes to the following solutions: water (control), 0.1% DMSO (vehicle), 1 μM CUR, or 1 μM micronized curcumin (MC) in zebrafish larvae 7 days post-fertilization (dpf). We analyzed locomotor activity (open tank test), anxiety (light/dark test), and avoidance behavior (aversive stimulus test). Moreover, we evaluated parameters of oxidative status (thiobarbituric acid reactive substances and non-protein thiols levels). MC increased the total distance traveled and absolute turn angle in the open tank test. There were no significant differences in the other behavioral or neurochemical outcomes. The increase in locomotion induced by MC may be associated with a stimulant effect on the central nervous system, which was evidenced by the micronization process.

Novel oil skimmer using bubble barrier and water jet suction — Prototype design and its tank test

This paper presents a new and innovative oil skimming device, which combines a bubble barrier and awater jet suction. The basic design philosophy of this device is based on the following two principles: (1) no oil-water separation on the water surface, and (2) no damming nor enclosure of oil by solid elements. By adoptingthese two principles, the device can have a very simple structure, light weight, which is quite different frommany conventional oil skimmers, can solve many problems that the conventional oil skimmers suffers from,such as poor responsibility to the high viscosity oil or low maneuverability of the vessel trailing the skimmer withhigh water flow resistance. The author prototyped an experimental model and conducted experiments toconfirm the effectiveness of these principles. It was found that the combination of the bubble barrier and thehigh-pressure water jet suction was effective for oil recovery to give a future vision of the oil recovery system.

Slamming Events of a Planing Hull and Wedge Water Entry Experiment: Comparisons and Insights on Fluid-Structure Interaction

Both towing tank experiments and wedge drop experiments are used to experimentally study slamming events on planning craft. The work presented in this paper shows a unique comparison between these two experiments. The first experiment was a towing tank test of a rigid hull in waves conducted at the U.S. Naval Academy. The second experiment was a series of free-falling water entry tests on a wedge conducted at Virginia Tech. In this paper, comparisons are drawn between the two experiments by using non-dimensional analysis and isolating similar slamming events. The non-dimensional impact velocities are chosen to be identical.

Non-micronized and micronized curcumin do not prevent the behavioral and neurochemical effects induced by acute stress in zebrafish

Curcumin, a polyphenol extracted from the rhizome of Curcuma longa L. (Zingiberaceae), presents neuroprotective properties and can modulate neuronal pathways related to mental disorders. However, curcumin has low bioavailability, which can compromise its use. The micronization process can reduce the mean particle diameter and improve this compound bioavailability and therapeutic potential. In this study, we compared the behavioral (in the open tank test, OTT) and neurochemical (thiobarbituric acid reactive substances (TBARS) and non-protein thiols (NPSH) levels) effects of non-micronized curcumin (CUR, 10 mg/kg, i.p.) and micronized curcumin (MC, 10 mg/kg, i.p.) in adult zebrafish subjected to 90-minute acute restraint stress (ARS). ARS increased the time spent in the central area and the number of crossings and decreased the immobility time of the animals. These results suggest an increase in locomotor activity and a decrease in thigmotaxis behavior in the OTT. Furthermore, ARS also induced oxidative damage by increasing TBARS and decreasing NPSH levels. ARS-induced behavioral and biochemical effects were not blocked by any curcumin preparation. Therefore, we suppose that curcumin does not have anti-stress effects on the ARS in zebrafish.

KLC4 shapes axon arbors during development and mediates adult behavior

Development of elaborate and polarized neuronal morphology requires precisely regulated transport of cellular cargos by motor proteins such as kinesin-1. Kinesin-1 has numerous cellular cargos which must be delivered to unique neuronal compartments. The process by which this motor selectively transports and delivers cargo to regulate neuronal morphogenesis is poorly understood. Our work implicates one kinesin light chain subunit, KLC4, as an essential regulator of axon branching and arborization pattern of sensory neurons during development. Using several live imaging approaches in klc4 mutant zebrafish, we show that KLC4 is required for stabilization of nascent axon branches and for proper microtubule (MT) dynamics. Furthermore, KLC4 is required for the contact repulsion necessary for tiling of peripheral axon arbors: in klc4 mutants, peripheral axons showed abnormal fasciculation, a behavior characteristic of central axons, suggesting that KLC4 patterns axonal compartments and helps define axon identity. Finally, we find that klc4 mutant adults show anxiety-like behavior in a novel tank test, implicating klc4 as a novel gene involved in stress response circuits.

Calocybe indicia extract modifies GABA and Serotonin levels to Alleviate anxiety in experimental adult Zebrafish models

Zebrafish (Danio rerio) was used as a model to study anxiety due to its physiological homology to humans. The pathophysiology of anxiety, even though still unclear, has been extensively studied in Zebrafish. Anxiety was induced by withdrawal after exposure to 0.5% ethanol, which proved to be anxiogenic, validated through the novel tank test. The light/dark test revealed that exposure to 0.5% ethanol had anxiolytic effects. The milky mushroom, Calocybe indica was used to treat anxiety since its anti-hypertensive effects have already been reported. Biochemical parameters such as GABA and MAO (A&B) were measured before and after treatment with different concentrations of C. indica and standard anxiolytic drug, Fluoxetine to compare and confirm the anxiolytic effect. The GABA content was found to be 119.9±1.99 mmoles/g tissue weight after treatment with 50 µg C. indica which was comparable to the normal group values (100±4.12). MAO (A&B) activity decreased which in turn increased serotonin levels with 25µg of C. indica. 25µg and 100µg concentration of the extract of C. indica was found to be optimum in reducing the level of anxiety.

An Interactive Numerical-Experimental Approach for Predicting the Vortex Induced Motion of Floating Production Systems

The Vortex Induced Motion (VIM) phenomenon is one of the well-known and important behavior experienced by all Floating Production Systems (FPSs) in operation under the effect of uniform current. In this phenomenon, under the effect of the formed vortices around the FPS hull, the platform oscillates primarily in a direction perpendicular to the flow resulting in a significant fatigue damage to the risers and the station keeping mooring system. Scale towing tank test has been the standard industry tool for predicting the VIM response, but it has its own limitations and has showed to significantly overpredict the VIM response when compared to the field measurements. In this paper, an interactive numerical-experimental approach has been developed to more accurately predict the VIM response and avoid the shortcomings of the model tests to bridge the gap between the model test predictions and the field measurements. Numerical and experimental data are presented to demonstrate the application and advantages of the proposed approach