Duration Of Swimming Research Articles

Efferent modulation of spontaneous lateral line activity during and after zebrafish motor commands.

Accurate sensory processing during movement requires the animal to distinguish between external (exafferent) and self-generated (reafferent) stimuli to maintain sensitivity to biologically relevant cues. The lateral line system in fishes is a mechanosensory organ that experiences reafferent sensory feedback, via detection of fluid motion relative to the body generated during behaviors such as swimming. For the first time in larval zebrafish (Danio rerio), we employed simultaneous recordings of lateral line and motor activity to reveal the activity of afferent neurons arising from endogenous feedback from hindbrain efferent neurons during locomotion. Frequency of spontaneous spiking in posterior lateral line afferent neurons decreased during motor activity and was absent for more than half of swimming trials. Targeted photoablation of efferent neurons abolished the afferent inhibition that was correlated to swimming, indicating that inhibitory efferent neurons are necessary for modulating lateral line sensitivity during locomotion. We monitored calcium activity with Tg(elav13:GCaMP6s) fish and found synchronous activity between putative cholinergic efferent neurons and motor neurons. We examined correlates of motor activity to determine which may best predict the attenuation of afferent activity and therefore what components of the motor signal are translated through the corollary discharge. Swim duration was most strongly correlated to the change in afferent spike frequency. Attenuated spike frequency persisted past the end of the fictive swim bout, suggesting that corollary discharge also affects the glide phase of burst and glide locomotion. The duration of the glide in which spike frequency was attenuated increased with swim duration but decreased with motor frequency. Our results detail a neuromodulatory mechanism in larval zebrafish that adaptively filters self-generated flow stimuli during both the active and passive phases of locomotion.NEW & NOTEWORTHY For the first time in vivo, we quantify the endogenous effect of efferent activity on afferent gain control in a vertebrate hair cell system during and after locomotion. We believe that this pervasive effect has been underestimated when afferent activity of octavolateralis systems is characterized in the current literature. We further identify a refractory period out of phase with efferent control and place this gain mechanism in the context of gliding behavior of freely moving animals.

Excess postexercise oxygen consumption decreases with swimming duration in a labriform fish: Integrating aerobic and anaerobic metabolism across time.

Many vertebrate animals employ anaerobic pathways during high-speed exercise, even if it imposes an energetic cost during postexercise recovery, expressed as excess postexercise oxygen consumption (EPOC). In ectotherms such a fish, the initial anaerobic contribution to exercise is often substantial. Even so, fish may recover from anaerobic pathways as swimming exercise ensues and aerobic metabolism stabilizes, thus total energetic costs of exercise could depend on swimming duration and subsequent physiological recovery. To test this hypothesis, we examined EPOC in striped surfperch (Embiotoca lateralis) that swam at high speeds (3.25 L s-1 ) during randomly ordered 2-, 5-, 10-, and 20-min exercise periods. We found that EPOC was highest after the 2-min period (20.9 mg O2 kg-1 ) and lowest after the 20-min period (13.6 mg O2 kg-1 ), indicating that recovery from anaerobic pathways improved with exercise duration. Remarkably, EPOC for the 2-min period accounted for 72% of the total O2 consumption, whereas EPOC for the 20-min period only accounted for 14%. Thus, the data revealed a striking decline in the total cost of transport from 0.772 to 0.226 mg O2 ·kg-1 ·m-1 during 2- and 20-min periods, respectively. Our study is the first to combine anaerobic and aerobic swimming costs to demonstrate an effect of swimming duration on EPOC in fish. Clarifying the dynamic nature of exercise-related costs is relevant to extrapolating laboratory findings to animals in the wild.

Effect of Exercise and Partial Sleep Restriction on Body Weight, Depressive-Like Behavior, and Hormonal Changes in Rat

Background: There is growing awareness that healthy sleep is an integral part of the quality of life. Objectives: The aim of this study was to examine the influence of an exercise training protocol and partial sleep restriction (SR) in male Wistar rats. We also assessed the changes in thyroxine (T4) and norepinephrine (NE) hormones. Methods: Rats were randomly housed in four groups including without exercise without SR (Non-Ex-Non-SR), without exercise with SR (Non-Ex-SR), with exercise without SR (Ex-Non-SR), and with exercise with SR (Ex-SR). The rats in the exercise groups ran on a treadmill for four weeks. Also, the columns-in-water model was applied to induce SR for 16 hours per day for a week. Then, the depressive-like behavior was assessed with the forced swimming test (FST) and blood samples were collected to measure the serum levels of T4 and NE hormones. Results: Body weight gain was significantly (P < 0.05) lower in exercise groups. During the SR period, weight losses of 24.83 and 15.50 g occurred in the Non-Ex-SR and Ex-SR groups, respectively. The lowest climbing and swimming durations were observed in the Non-Ex-SR group. For sleep-restricted rats, the plasma concentration of T4 was significantly (P < 0.05) lower and the NE level was higher although statistically insignificant. Conclusions: Taken together, our findings indicated that exercise can reduce the negative effects of sleep restriction. For knowing the negative effects of sleep restriction, we need more basic studies in this area.

Assessment of the tDCS Influence on Stress-Induced Disorders in Rats with Low Stress Sustainability and Endurance

Abstract The aim of study is to analyze the tDCS influence on stress-induced disorders in rats with low stress sustainability and endurance. The animals with a low stress sustainability and endurance were divided into 3 groups: the comparison 1, the comparison 2 and the main. The control group consisted of intact rats. The rats of the comparison group 1 were subjected to orthostatic stress 24 hours after the 1st forced swimming test. The rats of the comparison group 2 and the main one were conducted the 2nd forced swimming test on the 7th day of the experiment, and 24 hours later they were subjected to the orthostatic stress. Rats of the main group got tDCS sessions after the 1st forced swimming test. The development of the orthostatic stress is accompanied by an increase in plasma content the following components: adrenaline by 88.9%, ACTH in 10.5 times, corticosterone by 70.1%, IL-1β by 178.2%, IL-6 in 6.7 times, IL-10 by 37.1% in comparison with intact animals. The usage of tDCS in rats with low stress sustainability and endurance increased the swimming duration by 47.7%. During the OS it was also accompanied by a decrease in plasma content: adrenaline in 1.4 times, ACTH in 8.2 times, corticosterone in 1.4 times, IL-1β in 1.5 times, IL-6 in 2.2 times, IL-10 in 1.2 times, relative to the comparison group 2. The obtained data showed the essential effect of tDCS on stress-related changes in the content of cytokines and hormones of blood.

Regulation of lactate production through p53/β-enolase axis contributes to statin-associated muscle symptoms.

BackgroundStatin-associated muscle symptoms (SAMS) are the major adverse effects of the class of widely used lipid-lowering agents, and the underlying mechanism remains elusive. In this study, we investigated the potential contribution and molecular mechanism of increased lactate production to SAMS in mice.MethodsC57BL/6 J mice were administrated with lovastatin and exercise capacity and blood and muscle lactate levels were measured. A variety of metabolic and molecular experiments were carried out on skeletal muscle cell lines A-204 and C2C12 to confirm the in vivo findings, and to delineate the molecular pathway regulating lactate production by statins.FindingsBlood lactate levels of mice treated with lovastatin increased 23% compared to the control group, which was reproduced in type II predominant glycolytic muscles, accompanied with a 23.1% decrease of maximum swim duration time. The in vitro evidence revealed that statins increased the expression of muscle specific glycolytic enzyme β-enolase through promoting the degradation of basal p53 proteins, resulting in increased of lactate production. Co-administered with dichloroacetate (DCA), a reagent effective in treating lactic acidosis, reverted the elevated lactate levels and the decreased exercise capacity.InterpretationElevated lactate production by statins through the p53/β-enolase axis contributes to SAMS.FundThis work was supported by grants from the Science and Technology Development Fund (FDCT) of Macau (Project codes: 034/2015/A1 and 0013/2019/A1).

Effect of electroacupuncture at "Shenmen"(HT7) and "Sanyinjiao"(SP6) on energy metabolism in paraventricular nucleus of hypothalamus of insomnia rats

To observe the effect of electroacupuncture(EA) at "Shenmen"(HT7) and "Sanyinjiao"(SP6)on energy metabolism in paraventricular nucleus (PVN) of hypothalamus in insomnia rats, so as to explore its mechanism underlying improvement of insomnia. A total of 66 SD rats (half male and half female) were randomized into 3 groups：normal control, model and EA groups(n＝22 per group). The insomnia model was established by binding the rat for at least 4 h (step increase of 30 min per day), once daily for 15 days. EA (5 Hz /25 Hz, 0.5－1.0 mA) was applied to unilateral HT7 and SP6 for 15 min, once daily for 5 days. The rats' spontaneous activities during day and night were recorded by using the ClockLab Data Collection and Analysis System, and the duration of exhausted swimming was detected by using load-bearing endurance swimming test. The expression of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) of PVN tissue was assayed by Western blot, and the contents of acetyl coenzyme A (Ac-CoA) and Na＋-K＋adenosine triphosphatase (Na＋-K＋-ATPase) in the PVN tissue, and corticosterone (CORT) in plasma were assayed by ELISA. Changes of the ultrastructure of PVN cells were observed by transmission electron microscope. After modeling, the rats' daytime and nocturnal locomotor activities were significantly increased and decreased, respectively (P<0.05), and the duration of exhausted swimming was considerably shortened in the model group compared with that of the normal control group (P<0.05). The expression level of AMPK protein in the PVN was obviously up-regulated (P<0.05), and the contents of Ac-CoA and Na＋-K＋-ATPase in PVN and CORT in plasma were markedly decreased in the model control group relevant to the normal group (P<0.05). After EA intervention, the increased daytime locomotion and the decreased nocturnal activities, the shortened duration of exhausted swimming, the up-regulated expression of AMPK, and the decreased Ac-CoA, Na＋-K＋-ATPase and CORT contents were all reversed in the EA treated rats relevant to those of the insomnia rats (all P<0.05). Moreover, ultrastructural observation showed mitochondrial swelling and disappearance of partial ribosomes in the plasma of PVN cells in the model group, while in the EA group, only mild swelling of some mitochondria was found, being with basically normal nuclear membrane, mitochondria, rough endoplasmic reticulum, Golgi complex and ribosomes. EA at HT7 and SP6 has a positive effect in improving insomnia and insomnia-induced fatigue in insomnia rats, which may be associated with its effects in restraining the expression of AMPK protein, and up-regulating the contents of Ac-CoA and Na＋-K＋-ATPase in PVN and CORT in plasma.

Effect of moxibustion on inflammatory cytokine levels in hippocampus and hypothalamus in rats with fatigue

To investigate the effect of moxibustion of "Zusanli "(ST36) on levels of inflammatory cytokines in the hippocampus and hypothalamus regions of rats with fatigue, so as to reveal its anti-fatigue mechanism. Twenty-four male Sprague-Dawley rats were randomly divided into normal control, fatigue model, and moxibustion groups, with 8 rats in each group. The fatigue model was established by chronic weight-loaded exhaustive swimming. During modeling, the rats in the moxibustion group were given moxibustion (3 moxa cones, about 8 min in duration) at bilateral ST36, once every other day for 11 times in total. The duration of exhausted swimming was observed, and ELISA was used to measure the contents of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon gamma (IFN-γ) in the hippocampus and hypothalamus tissues. The duration of exhausted swimming was obviously prolonged on day 14 and 21 after moxibustion intervention relevant to the model group (P<0.05, P<0.01). The contents of IL-1β， IL-6 and TNF-α in the hippocampus were significantly increased in the model group than in the normal group (P<0.01), and that of hippocampal IL-6 was considerably decreased in the moxibustion group than in the model group (P<0.05). The content of hippocampal IFN-γ was significantly lower in the model group than in the normal group (P<0.05) and was increased mildly after moxibustion (P>0.05). No significantly changes were found in the levels of hypothalamic IL-1β， IL-6, TNF-α and IFN-γ after modeling and moxibustion (P>0.05), and in the levels of hippocampal IL-1β， TNF-α and IFN-γ after moxibustion (P>0.05)．. Moxibustion can significantly down-regulate hippocampal IL-6 content in fatigue rats, which maybe contribute to its effect in alleviating fatigue. Further studies need being conducted to identify this conclusion.

Behavioural alterations induced by the anxiolytic pollutant oxazepam are reversible after depuration in a freshwater fish

Anthropogenic pharmaceutical pollutants have been detected in nature across the globe, and recent work has shown negative effects of pharmaceuticals on the health and welfare of many animals. However, whether alterations can be reversed has been poorly investigated, although such studies are essential to assess the effects of high-peak exposure events in waterways where pharmaceutical concentrations are usually low. In this study, we investigated the effects of two concentrations (environmentally relevant 1 μg L−1 and high 100 μg L−1) of oxazepam, an anxiolytic commonly detected in aquatic environments, and whether behavioural alterations are reversible after depuration. Specifically, we measured daytime and night-time swimming activity and daytime behaviours related to boldness (foraging, sheltering and routine swimming activity) using the freshwater burbot (Lota lota). We found that both swimming activity and boldness were affected by oxazepam. Fish exposed to the higher level had a higher burst swimming duration (i.e., fast swimming bouts), both in the daytime and night-time trials. Further, fish exposed to the lower oxazepam level spent less time sheltering than control- and high-level exposed fish, but there was no difference between the control and high oxazepam treatments. For routine swimming activity, quantified in the boldness trials, and for latency to forage, there were no treatment effects. When retesting the fish after depuration, the detected behavioural alterations were no longer present. Since the magnitude of these effects were not consistent across endpoints, our study suggests that oxazepam might not be a great concern for this particular, stress tolerant, species, highlighting the importance of evaluating species-specific effects of pharmaceuticals. The observation that the effects we did find were reversible after depuration is encouraging, and indicates that rapid restoration of behaviours after removal from oxazepam contamination is possible.

PH Level of Swimming Pool, Athlete Behavior, and Dental Erosion at Swimmer Surabaya

Dental erosion potentially occurs in swimmer due to exposure to chlorine substances.The purpose of this research was to analyzed level of pH and behaviors related to incidence of dental erosion in swimmers. This research was analytical research with cross sectional design. The research undertaken in KONI Surabaya swimming pool with 33 samples. The process of data retrieval is done by filling questioner and dental examination by dentist. The variable of research was dental erosion, level of pH, swimming frequency, swimming duration, and time being swimmers. The results showed that the variables that have correlation with the incidence of dental erosion were time being swimmers (p = 0,050) and swimming frequency (p=0,032). Athletes can consume water or vegetable after do swim to reduce the acid levels in mouth because water and vegetable can neutralize the acid. In addition, athletes are advised to visit the dentist to get more benefits associated with dental erosion.

INFLUENCE OF PATRINIA SCABIOSIFOLIA ON THE RESISTANCE OF MICE TO WHOLE-BODY VIBRATION

The aim of the study was to evaluate the effectiveness of P. scabiosifolia in correcting the physiological and psychosomatic state of mice exposed to acute and prolonged whole-body vibration. The effect of a 40% water-alcohol tincture from the roots of P. scabiosifolia was investigated in CD-1 mice under the influence of whole-body vibration induced by a shaker or exposure to road transportation. Emotional, exploratory-oriented and motor behavioral components were observed in the open field. Physical performance was evaluated by the duration of swimming until fatigue with a 7% weight attached to the tail root. Metabolic indices were serum corticosterone, glycogen, lactate and adenosine triphosphate of the liver and skeletal muscle. The orally administered drug at a dose of 5 ml/kg optimized the behavioral reactions of the animals, increased their exercise performance, improved hormonal status, and energy metabolism in liver and skeletal muscle and tissues under the influence of whole-body vibration. The P. scabiosifolia tincture possesses a vibroprotectiveeffect and can be recommended for the prevention and treatment of neurophysiological disorders caused by whole-body vibration, in combination with basic therapy.

Maternal swimming pool exposure during pregnancy in relation to birth outcomes and cord blood DNA methylation among private well users

Swimming in pools during pregnancy may expose the fetus to water disinfection by-products (DBP). As yet, our understanding of the impacts on DBPs on the fetus is uncertain. Individuals with public water systems are typically exposed to DBPs through drinking, showering and bathing, whereas among those on private water systems, swimming in pools may be the primary exposure source. We analyzed the effects of maternal swimming on birth outcomes and cord blood epigenetic changes in the New Hampshire Birth Cohort Study, a cohort of pregnant women with households on private water systems. Information about swimming in pools during pregnancy was obtained from 1033 women via questionnaires. Swimming pool use and duration were modeled using linear regression with newborn weight, length, and head circumference (z-scores) and genome wide cord blood DNA methylation as the outcomes and with adjustment for potential confounders. Overall 19.7% of women reported swimming in a pool during pregnancy. Among swimmers, duration of swimming was inversely related to head circumference (−0.02 z-score per 10% increase in duration, P = 0.004). No associations were observed with birth weight, length or DNA methylation modifications. Our findings suggest swimming pool exposure may impact the developing fetus although longer-term studies are needed.

Forced Swim Reliability for Exercise Testing in Rats by a Tethered Swimming Apparatus.

To assess the physical capacity of rats in forced swim tests, the animal should perform a continuous activity (CON) at the surface to avoid apnea. Bobbing movement (BOB), vigorous paddling known as climbing (CLI), and diving activity (DIV) are inadequate swimming patterns known to increase the exercise intensity variability, impairing the test reliability. Thus, the exercise work accomplished and related physiological variables, such as the blood lactate concentration, may be unreproducible in forced swim. This study aimed to verify the exercise work reproducibility in rats with a 30-min test–retest at maximal lactate steady state (MLSS) intensity using a tethered-swimming apparatus that analyzes swimming patterns by the direct measurement of swimming force. Additionally, it was determined the swimming force and duration of CON, BOB, CLI, and DIV at physiologically different exercise-intensities. The swimming force at MLSS (n = 64) was 38 ± 7 gf.Kg-1, while the blood lactate concentration was 4.2 ± 1.6 mmol.L-1. In the test–retest (N = 23), swimming force (36.6 ± 7 gf.Kg-1 vs. 36.4 ± 7 gf.Kg-1) and blood lactate concentration (4.7 ± 1.7 mmol.L-1 vs. 4.2 ± 1.7 mmol.l-1) were similar, but only the swimming force was highly correlated (0.90 and 0.31). Although it was not statistically different, the swimming force for CON tends to be slightly lower than CLI and slightly higher than BOB independently of exercise-intensity. The CON pattern predominates (∼52.8 ± 18%) at intensities below and of MLSS but BOB was the swimming pattern more often observed above MLSS-intensity (52.6 ± 18%). The present study used a tethered swimming apparatus to investigate the reliability of forced swim tests for exercise testing in rats and better understand the swimming patterns when determining the MLSS, but the results can be extended to any study that rely on forced swim for exercise testing and training. The result suggests that, at least at intensities of physiological stability, the exercise work accomplished by rats is reproducible in forced swim, but the blood lactate concentration seems to be affected by other factors, such as the apnea and stress caused by the possibility of drowning, besides the exercise-intensity.

Antidepressant activity of 4-amino-5-(alkyl-, aryl-, heteryl)-1,2,4-triazole-3-thione benzylidene derivatives

The current market for antidepressants has a number of limitations, they have a high probability of development of adverse reactions, have low latitude and stability of the therapeutic effect, and also have a long latent period of action. Therefore, it seems obvious that there is a need to create new drugs that improve the quality of life, affect the mood and are safe. An analysis of literary sources has shown that derivatives of 1,2,4-triazole have a pronounced antidepressant effect and drugs such as Trazodone and Alprozalam are widely used in medical practice. The purpose of this work was to study antidepressant effects of 1,2,4-triazole derivatives and to make analysis of the dependence between chemical structure and pharmacological activity. Materials and methods. The search of antidepressants in the series of 1,2,4-triazole derivatives was performed on the basis of the classical model of R.D. Porsolt in the modification of E.V. Schetynin. Each animal was immersed for 6 minutes in a vessel filled with water at a temperature of 27 °C. The duration of active swimming was fixed (vigorous movements of all paws with active movement), passive swimming (weak bends of the paws necessary to support the body to swim) and immobilization (no swimming motions). In addition, the number of active swimming periods of different lengths and the number of very short immobilization periods of up to 6 seconds were counted. The index of depression (ID) was calculated due to the ratio of the very short periods number of immobilization to the total number of active swimming periods. The research results are processed by modern statistical methods of analysis using personal computer, including the standard program package Microsoft Office 2013 (Microsoft Excel) and Statistica ® for Windows 6.0. The average arithmetic mean (M) and standard mean errors (±m) were calculated. The statistical significance of intergroup differences according to the experimental data was established using Student's t-criterion. To study the dependence of the influence of benzylidene derivatives of 4-amino-5-(alkyl-, aryl-, heteryl)-2,4-dihydro-3H-1,2,4-triazole-3-thione on the duration of passive swimming and the duration of immobilization was carried out by correlation analysis. Results. Benzylidene derivatives of 4-amino-5-(alkyl-, aryl-, heteryl)-1,2,4-triazole-3-thione were used as test substances. The index of depression in the use of fluoxetine decreased to 70.92 % (P < 0.05), and with the use of trazodone to 76.95 % (P < 0.05). Compounds 26 and 32 statistically significantly lowered the index of depression to 86.66 and 81.24 %, respectively, which was higher than the activity of the used comparison drugs. The main indicator of rats despair was the duration of immobilization, decreased to 73.53 % (P < 0.05) and trazodone to 79.55 (P < 0.05) when administered with fluoxetine. When applying 1,2,4-triazole derivatives, the duration of immobilization of compound 32 was reduced to 89.53 % (P < 0.05), and compounds 23 to 87.05 % (P < 0.05). Conclusions. The most active compound according to the results of the study was compound 32, which reduced the average duration of immobilization in the experimental group to 89.53 % and had a rather low index of depression (0.34 ± 0.08, P < 0.05).

Egg white hydrolysate improves fatigue due to short-term swimming load test in mice.

We studied the effect of egg white hydrolysate (EWH) on swimming endurance in mice. 7‐week‐old male ddY mice (28–30 g) were divided into three groups and fed an AIN‐93G diet supplemented with casein (n = 8), EWH (n = 7), or egg white protein (EWP, n = 8) for 14 days. From day 11, the mice underwent a swimming test daily with a weight load equivalent to 10% of their body weight, and the lengths of time they swam were recorded. Blood was sampled for testing on the last day of the study. We observed that increases in the swimming duration through day 14 were significantly greater in the EWH group than in the casein group (p = 0.049). As a factor underlying this, the hexanoyl‐lysine level in blood was confirmed to be decreased in the former group (p = 0.013). These findings indicate that consumption of EWH extended the swimming duration and suggest the mechanistic involvement of an antifatigue effect mediated by its antioxidant activity.

Maternal Swimming Pool Exposure during Pregnancy in Relation to Birth Outcomes and Cord Blood DNA Methylation among Private Well Users

Abstract Swimming in pools during pregnancy may expose the fetus to water disinfection by-products (DBP). As yet, our understanding of the impacts on DBPs on the fetus is uncertain. Individuals with public water systems are typically exposed to DBPs through drinking, showering and bathing, whereas among those on private water systems, swimming in pools may be the primary exposure source. We analyzed the effects of maternal swimming on birth outcomes and cord blood epigenetic changes in the New Hampshire Birth Cohort Study, a cohort of pregnant women with households on private water systems. Information about swimming in pools during pregnancy was obtained from 1033 women via questionnaires. Swimming pool use and duration were modeled using linear regression with newborn weight, length, and head circumference (z-scores) and genome wide cord blood DNA methylation as the outcomes and with adjustment for potential confounders. Overall 19.7% of women reported swimming in a pool during pregnancy. Among swimmers, duration of swimming was inversely related to head circumference (−0.02 z-score per 10% increase in duration, P = 0.004). No associations were observed with birth weight, length or DNA methylation modifications. Our findings suggest swimming pool exposure may impact the developing fetus although longer-term studies are needed.

Faster and more efficient swimming: energy consumption of murine spermatozoa under sperm competition†.

ATP supply is essential for sperm performance and increases in ATP content coevolve with enhanced sperm swimming velocity as a response to sperm competition in rodents. ATP content is the balance between production and consumption but, although ATP production has received much attention, little is known about ATP consumption. The rate of ATP consumption is crucial for the propagation of the flagellar wave, becoming a main determinant of the time and distance sperm could move before exhausting their reserves. A high yield in distance per unit of ATP consumed (efficiency) could provide advantages in sperm competition. We characterized sperm ATP consumption rate in a group of mouse species with different sperm competition levels to understand its impact on swimming velocity, duration, and yield of sperm ATP reserves. Interspecific comparisons revealed that sperm of species with higher sperm competition levels had high ATP consumption rates and faster swimming velocity. Moreover, sperm that consumed ATP at a faster rate swam more efficiently, since they were able to cover more distance per unit of ATP consumed. Our results suggest that by coupling the advantages of higher ATP turnover rates to increased efficiency of ATP expenditure, sperm would respond to increasingly competitive environments while maintaining a positive ATP balance.

Antifatigue action of the 5-(furan-2-yl, 2-metylfuran-3-yl)-4-amino-1,2,4-triazole-3-thione alkyl derivatives

Body fatigue has many definitions but in general it can be described as a feeling of heaviness which occurs at the initiation or support physical or mental activities related to work at their normal abilities. Fatigue can be divided into physical and mental fatigue.&#x0D; Fatigue therapy problem is directed to find effective drugs, which affect the mechanisms of fatigue development and are aimed at restoring the cell functions, in particular, increase enzymes activity of the antioxidant defense system. Thus, pharmaceutical and medical practice is more interested in the tools that can help to improve the body's physical abilities and also to postpone fatigue or accelerate the recovery period of the body, but have fewer side effects.&#x0D; In our opinion these future drugs could be the 1,2,4-triazole derivatives which have low toxicity and wide spectrum of pharmacological action.&#x0D; Thus, the objective of our research was to investigate the antifatigue action of 1,2,4-triazole derivatives, as well as establish the patterns between the chemical structure and pharmacological action.&#x0D; The research was carried out on a group of white non-linear rats weighing 163-214. The study of antifatigue activity has been used forced immersion method in water with a load of 10% of the rats weight.&#x0D; Among the alkyl derivatives of 5-(2-methylfuran-3-yl)-4-amino-4H-1,2,4-triazole-3-thiones (2a–g) the most expressive antifatigue action had the 3-octylthio-5-(2-methylfuran-3-yl)-4-amino-1,2,4-triazole (2f). Its application had led to the increasing of the forced swimming duration in comparison with the control group to 15.79%.&#x0D; It should be noted that the 2-methylfuran-3-yl administration to the С5 carbon atom leads to a slight increasing of the antifatigue actions at studied 1,2,4-triazole derivatives.&#x0D; After analyzing the data, we have established some patterns of dependings on the chemical structure of the antifatigue action of the synthesized compounds. For further in-depth research it is recommended to study the compound 1d, which by its antifatigue effect exceeds the referent Riboxinum.

Does experimental cortisol elevation mediate risk-taking and antipredator behaviour in a wild teleost fish?

The hypothalamic-pituitary-interrenal (HPI) axis is centrally implicated in stressor mitigation in teleost fishes. Sustained HPI axis activation can be detrimental to the physiological functioning of an organism and can result in fitness-related trade-offs. Predator-induced mortality is known to be higher in stressed fish than in unstressed conspecifics, suggesting a role for the HPI axis in mediating fish behaviour. However, the underlying specific mechanism(s) for this phenomenon is(are) unknown. The purpose of the current study was to address how the HPI axis influences risk-taking, and antipredator behaviours in a wild teleost, the pumpkinseed sunfish (Lepomis gibbosus). Here, individual juvenile pumpkinseed were implanted either with cocoa butter as a sham control or with a biologically-relevant concentration of cortisol. Forty-eight hours post-implantation, fish were assessed for behavioural metrics associated with boldness and risk taking in three sequential behavioural tests: (i) a predation-risk test, (ii) an exploration tendency test, and (iii) a shoaling tendency test, with test order randomized among different trials. Cortisol treatment had no influence on antipredator, exploratory, or shoaling behaviours. However, post-attack swimming duration (in predation-risk test) and exploratory activity (in Z-maze exploration test) were significantly affected by body mass. Collectively, our results indicate that cortisol may not have a role in mediating sociability, boldness, and risk-taking behaviours in pumpkinseed sunfish, at least under the current laboratory conditions. However, cortisol may nonetheless play a role in mediating predator-prey interactions in fishes in more natural environmental settings that were not considered here.

A semi-automatic and quantitative method to evaluate behavioral photosensitivity in animals based on the optomotor response (OMR).

ABSTRACTThe optomotor response (OMR) is a locomotor behavior of animals that is induced by moving repetitive visual stimuli. This characteristic helps animals particularly when stabilizing and maintaining position in schools and herds. Here, we developed a simple but sensitive method for quantifying the OMR using medaka (Oryzias latipes) as a model. This method, which simply requires video-recorded behavior, free tracking software, and a generic spreadsheet program, enables the evaluation of spectral sensitivity by researchers with little knowledge about the behavioral characteristics of the test animal or of the OMR. Based on a manual method, we reported previously that wild-type and red-colorblind medaka exhibited an OMR up to λ=830 and 740 nm, respectively. However, the present method, which quantifies the OMR according to three parameters (starting time, duration, and total distance of swimming) that are calculated based on a series of x–y coordinates of the moving fish, supported that conclusion and further indicated that both strains perceive light at even longer wavelengths. This low-cost, quantitative, and semi-automatic method would widen the opportunities to unveil behavioral photosensitivity in animals of interest.This article has an associated First Person interview with the first author of the paper.

Effects of 8 Weeks of Plyometric Exercise on Certain Physiological Parameters and Performance of Swimmers

In this study, it is aimed to review the effects of 8 week plyometric exercises on certain physiological parameters and freestyle swimming performance of swimmers of age 10-11 who practice swimming with a licence in city of Van. Study group has been created by 24 male volunteer swimmers who practice swimming with a licence in city of Van. 24 volunteer athletes aged 10-11, who are licenced swimmers for two years and who exercise regularly 5 days a week have been selected for the study. The athletes are randomly divided into experimental and control groups of 12. Throughout the study, in addition to swimming exercises, experimental group is scheduled to 3 days a week plyometric exercise program. Control group is not given any additional exercise except from the swimming exercises. It is seen that the obtained data does not show normal distribution and non-parametric tests of Mann Whitney U and Wilcoxon Test are used for data analysis. Significance level is taken as p&lt;0,05. As per obtained data, pretest and post test data of male swimmers of experimental group show that horizontal and vertical leaps, anaerobic power, 30m sprint, hand grip right and left, 25 and 50 m freestyle swimming parameters showed statistical significant difference; whereas for control group, weight, height, body mass index, anaerobic power and right and left hand grip force parameters showed statistical significant difference (p&lt;0,05). When the pretest and posttests of experimental and control groups are compared, only vertical leap parameter showed significant difference in favor of the experimental group (p&lt;0,05) and for the other parameters, no statistical significant difference is seen (p&gt;0,05). As a result, it is seen that the 8 week plyometric exercise has a significant effect on vertical leap and even though not statistically significant, it is pondered that it has a positive effect on freestyle swimming duration of experimental group, compared to that of control group.