A novel small-animal locomotor activity recording device for biological clock research

The rodent running-wheel recording apparatus is a reliable approach for studying cir-cadian rhythm.This study demonstrated how to construct a simple and intelligent running-wheel recording system.The running wheel was attached to the cage's base,whereas the Hall sensor was attached to the cage's cover.Then,the RJ25 adaptor relayed the running signal to the main control board.Finally,the main control board was connected to the USB port of the computer with the USB connection.Data were collected using the online-accessible,self-created software Magturning.Through Magturning,generated data were saved and exported in real time.Afterward,the device was validated by collecting data on the locomotor activities of mice under dif-ferent light conditions.In conclusion,this new device can record circadian activity of rodents.Our device is appropriate for interdisciplinary investigations related to biological clock research.

Differential Effects of Valproic Acid on Immobility Responses and Locomotor Activity in Female and Male Rats

Valproic acid (VPA) is used in the treatment of epilepsy and behavioral disorders. However, the exposure to VPA during pregnancy increases the risk of having offspring with autism spectrum disorder (ASD). Reports indicate that men are more likely to suffer ASD than women who were exposed to VPA prenatally. Few studies have related the sex differences and behavioral changes in the ASD rat model. Our aim was to determinate whether male and female Wistar rats whose mothers were exposed to either VPA (600 mg/kg;animal model for ASD) or saline (0.9%) i.p. at 12.5 day of gestation, have different effects on immobility induce by clamping (IC), dorsal immobility (DI), catalepsy, locomotor activity, stereotypes, and analgesia (tail flick). For this purpose, we made four groups (n = 8). Group: A) saline male rats, B) saline female rats, C) VPA male rats and D) VPA female rats. At 35 (prepubertal age), 56 (postpubertal age) and 180 days, we tested the behaviors previously mentioned. Finding that VPA has the same effect on IC, catalepsy, and analgesia in male and female rats, the time of these tests was increased. However, VPA only has an effect on DI in males but not in female rats. On the contrary, there is hyperactivity and an increase of stereotypes in female but not in male rats. Thereby, VPA has an effect on the three immobility responses tested (IC, DI and catalepsy), locomotor activity and analgesia but in a differential way on DI, stereotypes and locomotor activity between male and female rats.

Locomotor activity and anxiety status, but not spatial working memory,are affected in mice after brief exposure to cuprizone

Chronic long-term exposure to cuprizone causes severe brain demyelination in mice,which leads to changes in locomotion,working memory and anxiety.These findings suggest the importance of intact myelin for these behaviors.This study aimed to investigate the possible behavioral changes in mice with mild oligodendrocyte/myelin damage that parallels the white matter changes seen in the brains of patients with psychiatric disporders.We used the cuprizonetreated mouse model to test both tissue changes and behavioral functions（locomotor activity,anxiety status,and spatial working memory）.The results showed that mice given cuprizone in their diet for 7 days had no significant myelin breakdown as evaluated by immunohistochemical staining for myelin basic protein,while the number of mature oligodendrocytes was reduced.The number and length of Caspr protein clusters,a structural marker of the node of Ranvier,did not change.The locomotor activity of the cuprizonetreated mice increased whereas their anxiety levels were lower than in normal controls;spatial working memory,however,did not change.These results,for the first time,link emotion-related behavior with mild white matter damage in cuprizone-treated mice.

Effect of intensity and duration of anthropic noises on European mink locomotor activity and fecal cortisol metabolite levels

Human activities involving noise emission can affect wild animals.European mink was exposed to road noise and human voice playbacks to analyze how sound intensity level and duration of both noises altered the time that individuals were active and if their fecal cortisol metabolite(FCM)levels varied.A Hierarchical Analysis Cluster was performed to establish 2 mink groups with respect to both noise source type:short duration/low intensity(SL)and long duration/high intensity(LH).We performed general linear mixed models to evaluate the variation in locomotor activity duration(s)and FCM(nanogram per gram)levels,respectively.The results showed both road noise and human voices decreased locomotor activity duration in SL more sharply compared with LH,and human voices were the triggers that induced the most pronounced response to both exposure conditions.FCM(ng/g)levels increased in SL compared with LH during road noise while the opposite happened during human voices.Differences based on sex and age of individuals were observed.In conclusion,noise characteristics given by the sound type determined the variations in locomotor activity duration while noise exposure level determined the variations in FCM(ng/g)levels.Attention should be paid to noisy activities(e.g.,recreational activities for visitors in protected natural areas)and loud groups of people to conserve wildlife,especially noise sensitive species.

Increased locomotor activity in estrogen-treated ovariectomized rats is associated with nucleus accumbens dopamine and is not reduced by dietary sodium deprivation

Estrogens are well known to increase locomotor activity in laboratory rodents;however,the underlying mechanism remains unclear.We used voluntary wheel running by female rats as an index of locomotor behavior to investigate this issue.We first determined whether the estrogen-induced increase in locomotion was susceptible to inhibition by a physiological challenge,and next whether it was associated with dopaminergic activation in the central reward area,nucleus accumbens.Ovariectomized rats were given estradiol or the oil vehicle and housed in cages with or without running wheels.All rats were given regular rodent chow for 1 week,a sodium-deficient diet for the next week,and then were returned to a regular diet for another week.At the end of the last week,all rats were killed,brains were extracted and dopamine levels in the nucleus accumbens were measured.As expected,estradiol treatment increased distance run.Surprisingly,dietary sodium deprivation further increased running,but this appeared to be related to experience with wheel running,rather than to sodium deprivation,per se.Dopamine was greater in the nucleus accumbens of estradiol-treated rats that ran compared to all other groups.Thus,the estrogen-induced increase in locomotion is a robust phenomenon that is not inhibited by a body sodium challenge and is associated with elevated levels of dopamine in reward pathways.These findings raise the possibility that the estrogen-induced increase in locomotor activity,which occurs during a hormonal milieu conducive to reproduction,may reflect mate-seeking behavior and,thereby,maximize reproductive success.

CDK5-mediated phosphorylation of CP190 may regulate locomotor activity in adult female Drosophila

The three-dimensional organization of the genome plays a crucial role in regulating gene expression patterns in metazoans（Ong and Corces,2014）.The nuclear architectural proteins are known to facilitate the formation of topological domains within the genome through mediating inter-and intra-chromosomal interactions.In vertebrate,CCCTC-binding factor（CTCF）is the main architectural protein that mediates long-range chromosomal interactions among its DNA binding sites through a process that is stabilized by cohesin （Parelho et al., 2008; Wendt et al., 2008）.

The effects of inactivated SARS-CoV-2 vaccination and subsequent infection of pregnant mice on the behaviors of offspring

The mass inoculation of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)vaccines to induce herd immunity is one of the most effective measures we can deploy in the fight against coronavirus disease 2019(COVID-19).Pregnant women are prone to a higher risk of COVID-19,and maternal infection is a risk fac-tor for a range of neurological disorders leading to abnormal behavior in adulthood.However,there are limited clinical data to support whether vaccination or infection post-immunization in pregnant women can affect the behavioral cognition of fetuses in adulthood.In this study,human angiotensin-converting enzyme 2 pregnant mice(F0 generation)were immunized with CoronaVac and then infected with SARS-CoV-2.Subsequently,we analyzed the behavioral cognition of their adult offspring(F1 gen-eration)using the open-field test and Morris water maze test.The adult F1 generation did not exhibit any impairments in spontaneous locomotor activity or spatial refer-ence memory.

Knockout of cryptochrome 1 disturbs the locomotor circadian rhythm and development of Plutella xylostella

Cryptochrome 1(CRY1)functions as a light-responsive photoreceptor,which is crucial for circadian rhythms.The identity and function of CRY1 in Plutella xylostella remain unknown.In this study,cryl was cloned and identified in P xylostella.Then,a cry1-knockout strain(Cry1-KO)of P xylostella with a 2-bp deletion was established from the strain Geneva 88(G88)using the CRISPR/Cas9 technology.No daily temporal os-cillation of cryl was observed in G88 and Cry1-KO,and cryl mean daily transcription of Cry1-KO was lower than that of G88.Both G88 and Cry1-KO demonstrated rhythmic locomotion under the light/dark condition with Cryl-KO being more active than G88 in the daytime,whereas Cry1-KO completely lost rhythmicity under constant darkness.The developmental period of pre-adult of Cry1-KO was longer than that of G88;the lifespan of the Cry1-KO male adult was shorter than that of G88;the fecundity of Cry1-KO was lower than that of G88;and Cry1-KO showed lower intrinsic rate of increase(r),net repro-duction rate(Ro),finite increase rate(a),and longer mean generation time(T)than G88.Our results indicate that cryl is involved in the regulation of locomotor circadian rhythm and development in P xylostella,providing a potential target gene for controlling the pest and a basis for further investigation on circadian rhythms in lepidopterans.

神经损伤是轮胎橡胶衍生污染物6PPDQ引起虹鳟急性毒性的重要原因

N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine quinone(6PPDQ)has attracted significant attention due to its highly acute lethality to sensitive salmonids.However,studies investigating the mechanisms underlying its acute toxicity have been lacking.In this work,we demonstrated the sensitivity of rainbow trout to 6PPDQ-induced mortality.Moribund trout exhibited significantly higher brain concentrations of 6PPDQ compared to surviving trout.In an in vitro model using human brain microvascular endothelial cells,6PPDQ can penetrate the blood–brain barrier and enhance blood–brain barrier permeability without compromising cell viability.The time spent in the top of the tank increased with rising6PPDQ concentrations,as indicated by locomotion behavior tests.Furthermore,6PPDQ influenced neurotransmitter levels and m RNA expression of neurotransmission-related genes in the brain and exhibited strong binding affinity to target neurotransmission-related proteins using computational simulations.The integrated biomarker response value associated with neurotoxicity showed a positive linear correlation with trout mortality.These findings significantly contribute to filling the knowledge gap between neurological impairments and apical outcomes,including behavioral effects and mortality,induced by6PPDQ.

Daily activity rhythms, chronotypes, and risk-taking behavior in the signal crayfish

Consistent inter-individual differences in daily activity rhythms(i.e.,chronotypes)can have ecological consequences in determining access to food resources and avoidance of predators.The most common measure to characterize chronotypes in animals as well as humans is the onset of activity(i.e.,early or late chronotypes).However,daily activity rhythms may also differ in the relative amount of activity displayed at particular time periods.Moreover,chronotypes may also be linked to other consistent inter-individual differences in behavior(i.e.,personality),such as the propensity to take risks.Here,we used the signal crayfish Pacifastacus leniusculusto test the presence of chronotypes and risk-taking personality traits and a potential behavioral syndrome between these traits.We first exposed crayfish to 5 days of light-darkness to measure daily activity rhythms and then we applied a visual predator-simulating stimulus in 2 different contexts(neutral and food).Our results showed consistent(i.e.,across 5 days)inter-individual differences in the relative nocturnal activity displayed in the early and middle,but not in the late part of darkness hours.Moreover,while crayfish displayed inter-individual differences in risk-taking behavior,these were not found to be consistent across 2 contexts.Therefore,we were not able to formally test a behavioral syndrome between these 2 traits.In conclusion,our study provides the first evidence of chronotypes in the relative amount of activity displayed at particular time periods.This could be a valuable information for applied ecological aspects related to the signal crayfish,which is a major invasive species of freshwater ecosystems.

An Efficient and Reliable Assay for Investigating the Effects of Hypoxia/Anoxia on Drosophila

Stroke is a leading cause of death worldwide. Up to one thousand potential drugs or interventions have been developed to treat stroke, out of which;60 have gone on to clinical trials. However, none of them has been successful. New insights into the molecular and cellular mechanisms of ischemia-induced injury are needed for discovering new therapeutic targets. Recently, Drosophila has been used to uncover new hypoxia-related genes. In this study, we describe an efficient and reliable assay with a sophisticated apparatus for studying the effects of oxygen deprivation on flies. Using this assay, wild-type flies were exposed to an anoxic environment for varying lengths of time, then the cumulative death rate and mobility recovery were systematically analyzed. We found that anoxia for over one hour caused lethality. The cumulative death rate on day 5 after anoxia was linearly and positively correlatedwith the duration of anoxia, and reached 50% when the duration was 2.5 h–3 h. We also found that the mobility recovery in normoxia was slow, as the climbing ability remained largely unchanged 4 h–6 h after 2.5-h of anoxia.We suggest that 2.5 h–3 h of anoxia and 4 h–6 h of recovery before mobility analysis are appropriate for future use of the anoxia assay.

Drosophila melanogaster as a model system of aluminum toxicity and aging

The aim of this study was to investigate the toxic effects of aluminum （A1） on the model organism-Drosophila melanogaster. The study is especially concerned with the effects of aluminum on the fruit fly＇s development, life span, and circadian rhythm in rest and activity. Flies were exposed to aluminum in concentrations from 40 to 280 mg/kg in rearing media or the flies were raised on control medium. Moreover, the life span of insects exposed to aluminum containing 40, 120, or 240 mg/kg of A1 in the medium, only during their larval development, during the whole life cycle and only in their adult life was tested. To check if aluminum and aging cause changes in D. melanogaster behavior, the locomotor activity of flies at different ages was recorded. Results showed that aluminum is toxic in concentrations above 160 mg/kg in the rearing medium. Depending on A1 concentration and time of exposure, the life span of the flies was shortened. At intermediate concentrations （120 mg/kg）, however, A1 had a stimulating effect on males increasing their life span and level of locomotor activity. At higher concentration the aluminum exposure increased or decreased the level of locomotor activity ofD. melanogaster depending on age of flies. In addition, in the oldest insects reared on aluminum supplemented media and in mid-aged flies reared on the highest concentration of A1 the daily rhythm of activity was disrupted.

Disruption of dopamine D1 receptor phosphorylation at serine 421 attenuates cocaine-induced behaviors in mice

Dopamine D1 receptors（D1Rs） play a key role in cocaine addiction, and multiple protein kinases such as GRKs, PKA, and PKC are involved in their phosphorylation. Recently, we reported that protein kinase D1 phosphorylates the D1 R at S421 and promotes its membrane localization. Moreover, this phosphorylation of S421 is required for cocaineinduced behaviors in rats. In the present study, we generated transgenic mice over-expressing S421A-D1 R in the forebrain. These transgenic mice showed reduced phospho-D1R（S421） and its membrane localization, and reduced downstream ERK1/2 activation in the striatum. Importantly, acute and chronic cocaine-induced locomotor hyperactivity and conditioned place preference were significantly attenuated in these mice. These findings provide in vivo evidence for the critical role of S421 phosphorylation of the D1 R in its membrane localization and in cocaine-induced behaviors. Thus, S421 on the D1 R represents a potential pharmacotherapeutic target for cocaine addiction and other drug-abuse disorders.