Comparison of exploratory behavior of male and female woodlice (Armadillidium vulgare)

There are several studies in the literature showing that male and female rats explore novel environments and exhibit different exploration patterns when submitted to different apparatuses. In general, female rats spend more time moving and exploring the apparatuses than males do. A previous study showed that male woodlice (Armadillidium vulgare) explore novel environments in a very similar way to male rats (Rattus norvegicus) when tested in apparatuses analogous to the open-field test and light/dark box. Since that study was conducted only with male rats and woodlice, and since they exhibited very similar patterns of behavior, the present experiment aimed at investigating whether male and female woodlice explore novel environments with different behavioral patterns. Female and male woodlice were tested in the open-field and in the dry/moist box. Results obtained in the open-field test showed that both males and females remained longer in the corners than along the walls and avoided staying in the center. However, females remained longer along the walls and less in the corners. In the dry/moist box, there were no significant differences between the sexes: both females and males remained significantly longer in the moist compartment.

Confusion and countermeasures of the non-conditioned anxiety test in rodent laboratory animals / 中华行为医学与脑科学杂志

Anxiety is a major mood disorder, and the high morbidity, co-morbidity and disability of anxiety disorders seriously affect people's quality of life, so the importance and urgency of research on anxiety cannot be overstated. Animal models are the main carriers for studying the mechanism of disease occurrence and development, drug efficacy evaluation and drug development.Unconditioned anxiety model is a common anxiety model.Elevated plus maze test, open field test and light-dark box test are widely accepted paradigms for the detection of unconditioned anxiety.This kind of behavioral paradigm based on environmental exposure takes advantage of the conflict between curiosity and fear of the unfamiliar environment to simulate and detect the anxiety of animals.However, the validity of these behavioral paradigms for evaluating anxiety in animals is questionable.In this paper, we discuss the concept of anxiety, the definition of anxiety behavior in the behavioral test of unconditioned anxiety, and the factors to be considered in the test of unconditioned anxiety behavior.On this basis, new solutions were proposed to the contradictions and blind spots in order to improve the test paradigm of anxiety behavior and provide a more reliable animal model for the evaluation of anxiety.This paper presents a new approach to address the contradictions and blind spots of this paradigm.

Effect of Ocimum sanctum leaf extract in animal models of anxiety

Background: Anxiety is one of the most prominent psychiatry disorders related to common stress. Approximately two-thirds of anxious patients respond to currently available treatments but the magnitude of problem is still disappointing. Ocimum sanctum (OS), a perennial shrub grown in India, has anti-stress activity. Yet, there is a paucity of data regarding this. Aims and Objectives: This study aims to evaluate the anti-anxiolytic effect of OS leaf extract (OSLE) in Swiss albino mice. Materials and Methods: Elevated plus maze (EPM) and open field test are standardized tests done for screening anxiolytic effects of drugs. The animals were grouped and the tests were conducted and the results were compared with the standard drug diazepam. Results: There was significant increase in the time spent in open arm and number of open arm entries in the diazepam group and group receiving OSLE at dose of 100 mg/kg and 200 mg/kg in EPM test. Furthermore, in the open field test, there was significant increase in the number of square crossed and rearing in the diazepam group and OSLE at dose of 100 mg/kg and 200 mg/kg. Conclusion: OSLE shows significant anxiolytic effect in EPM and open field test models in Swiss albino mice. This can be further studied to open up new possibilities for new drug development for anxiety.

Behavioral characterization of ayahuasca treatment on Wistar rats in the open field test

Abstract Ayahuasca (AYA) is a psychedelic beverage with therapeutic potential for many mood and anxiety disorders. Although there are some preclinical studies, no published reports have tested the behavioral effects of AYA gavage in animal models. This investigation aimed to characterize the behavior of Wistar rats after acute ingestion of AYA for 40 min in the open field test (OFT). The sample consisted of three experimental groups treated with different dosages of AYA (125, 250, or 500 mg kg-1) and a control group. Each group consisted of 10 participants. After gavage, the number of crossings of the OFT grid lines, latency to enter the central area of the device, grooming frequency, and time spent in the central perimeter of the device were immediately evaluated. Analyses were based on one-way ANOVA and a linear-regression mixture model for longitudinal data. AYA intake did not interfere with habituation. The 500 mg kg-1 group showed a decrease in the time spent in the center of the device and in the number of crossings compared to the control group in the last 10 min. These results suggest that gavage with AYA did not interfere with the results, and the behavioral effects were perceived only between 30 and 40 min after gavage. Taken together, the results indicate that three aspects should be considered in OFT studies of AYA acute effects: the moment when the observation starts, the observation period, and the AYA dosage.

Evaluation of subchronic formaldehyde exposure in rats with open field test / Evaluación de la exposición al formaldehído subcrónico en ratas con prueba de campo abierto

SUMMARY: Formaldehyde (FA), which is an indispensable chemical substance in anatomy and pathology, is a very harmful substance for living things. In our study, the purpose was to investigate the changes in behavior of rats exposed to subchronic formaldehyde with open field test. We divided 24 Wistar-Albino rats into 3 groups. The first group (n=8) was identified as the control group, and normal air breathing was ensured. Low-dose FA (mean 1 ppm) was inhaled in the second group, and high-dose FA (mean 10 ppm) was inhaled in the third group. FA exposure was done for 4 hours, 12 weeks, and 5 days a week. The rats were subjected to open field test during the first week and the last week of FA exposure. We observed significant decreases in the number of vertical movements and grooming in rats in the experimental group compared to the control group in the open field test (p 0.05). As a conclusion, we can argue that FA causes changes in the behaviors of rats regardless of dose and duration.

RESUMEN: El formaldehído (FA), una sustancia química indispensable en la anatomía y patología, pero es un elemento sumamente nocivo para todos los seres vivos., El objetivo de nuestro estudio fue investigar los cambios en el comportamiento de ratas expuestas a formaldehído subcrónico con prueba de campo abierto. Utilizamos 24 ratas Wistar-Albino divididas en 3 grupos. El primer grupo (n = 8) se identificó como el grupo de control y se aseguró una respiración normal de aire. En el segundo grupo se inhalaron dosis bajas de FA (media de 1 ppm) y en el tercer grupo se inhalaron dosis altas de FA (media de 10 ppm). La exposición a FA se realizó durante 4 horas, 12 semanas y 5 días a la semana. Las ratas fueron sometidas a una prueba de campo abierto durante la primera semana y la última semana de exposición a FA. Observamos disminuciones significativas en el número de movimientos verticales y acicalamiento en ratas en el grupo experimental en comparación con el grupo control en la prueba de campo abierto (p 0,05). Como conclusión, podemos argumentar que la AF provoca cambios en el comportamiento de las ratas independientemente de la dosis y la duración.

Changes in expression of estrogen receptor α and β associated with anxiety-like behavior of dams in dams-offspring separation of C57BL/6 J mice / 解剖学报

Objective To investigate the effects of dams-offspring separation on anxiety-like behaviors of dams, and if these anxiety-like behaviors of dams are associated with estrogen receptorα(ERα) and β( ERβ)in some brain regions. Methods Thirty C57BL/6 J female mice were divided into three groups, control group (CG, n= 10,non-isolated group), short-term separation group( SG,/i= 10, dams were separated from their offspring for 15 minuts per day from the second day to the tenth day after childbirth ) and long-term separation group ( LG, n = 10, dams were separated from their offspring for 3 hours per day from the second day to the tenth day after childbirth ). Anxiety-like behaviors of dams were evaluated in an open-field (OF) and elevated plus-maze test ( EPM ). The level of ERα- immunoreactive neurons (ERα-IRs) and ERβ-immunoreactive neurons (ERβ-IRs) in three brain regions including medial preoptic area (mPOA), hypothalamic ventromedial nucleus (VMH) and medial amygdaloid nucleus ( MeA) were analyzed. Results In OF, compared to CG group and SG group, LG group had significantly less time in center area, crossing number and total distance(P0.05 ). In EPM, compared to CG group and SG group, LG group had significantly less percentage of time, distance in open arms and total distance(P<0.001 ). Compared to CG group and SG group, LG group had significantly less ERa-IRs and ERβ-IRs in mPOA, VMH, and MeA(P<0.01). Conclusion Dams that are long-termly separated from their offspring may have anxiety-like behavior, and this behavior may be related to the significant reduction of ERa and ERβ in these brain regions.

Neurotoxicity and hematotoxicity of maternal exposure to 1-bromopropane in male offspring rats / 中国职业医学

OBJECTIVE: To observe the neurotoxicity and hematotoxicity of maternal exposure to 1-bromopropane(1-BP) on the offspring rats by the breast-feeding route. Method A total of eight specific pathogen free female rats and their 64 male newborn rats were divided into the control group and the exposure group, with four lactation female rats and their 32 male newborn rats in each group. The female rats in exposure group were intragastrically administered with 700.00 mg/kg body mass of 1-BP during lactation, and the control group was given equal volume of corn oil for 21 days, once a day. The body mass of female rats and their offspring rats were measured during the exposure period. After exposure, the Morris water maze and the open field tests were performed in male offspring. The blood samples of offspring were collected for blood routine and blood biochemical indexes detection. The histopathological examination was performed in the hippocampus in the male offspring. RESULTS: A litter of eight pups in the exposure group began to die one day after the mother rat was exposed to 1-BP, and all rats died on the ninth day after exposure. There was no significant difference in the body mass of female rats between the exposure group and the control group(P>0.05). The body mass of offspring rats in the exposure group was lower than that in the control group at the same time point from the first day to the 21 st day of the female rats exposed to 1-BP(all P<0.05). In the orientation navigation experiment, the escape latency time on the first, the second day and the total distance on the first day in the offspring of the exposure group were significantly prolonged than those in the control group at the same time points(all P<0.05). The number of times of crossing the platform of offspring rats in the exposure group was less than that in the control group in the spatial exploration test(P<0.01). In the open field test, there was not statistical significance of the activity, rest time ratio, total distance, the distance ratio and time ratio in the central region in the offspring between the two groups(all P>0.05). The counts of white blood cells, neutrophils, lymphocytes, and average red blood cell width, platelet ratio and average platelet volume of the offspring of the exposure group decreased(all P<0.05), the serum levels of globulin, total protein, triacylglycerol and total bilirubin decreased(all P<0.05), and the albumin/globulin ratio and serum glucose level increased(all P<0.05), when compared with that of the control group. Histopathological examination results showed that the nerve fibers were loose in the hippocampal dentate gyrus area, and there were necrotic neurons and loss of nerve fibers in the CA1 area of the offspring rats. CONCLUSION: Maternal exposure to 1-BP during lactation can induce neurotoxicity and hematotoxicity to offspring rats. The neurotoxicity mainly caused damage to the central nerve system, which affected the learning and memory function of the offspring rats. The reason may be related to the damage caused by 1-BP on the hippocampal function.

Avaliação neurocomportamental e níveis de acetilcolinesterase cerebral em ratos expostos subcronicamente ao fipronil / Neurobehavioral assessment and brain acetylcholinesterase levels in rats subchronically exposed to fipronil

O fipronil é um inseticida de toxicidade seletiva amplamente empregado na agricultura e na medicina veterinária. Porém, há relatos de efeitos neurotóxicos dessa substância, que geram prejuízos para vertebrados. Avaliou-se a atividade locomotora, a coordenação motora e a atividade da enzima acetilcolinesterase cerebral em ratos expostos ao fipronil. Ratos Wistar machos adultos (n=15) receberam fipronil em dose de 30mg/kg, por via oral, durante 15 dias; o grupo controle (n=15) foi tratado com solução fisiológica, por via oral, no mesmo período. No 16° dia de experimentação, os animais foram submetidos aos testes de arena de campo aberto e hole board. No 17° dia, foram anestesiados e eutanasiados, procedendo-se à coleta de órgãos, e posteriormente foi feita a avaliação da AChE cerebral. A exposição ao fipronil não provocou alterações significativas sobre a coordenação motora e a atividade locomotora, porém gerou inibição significativa da atividade da acetilcolinesterase cerebral. Esses achados sugerem que o fipronil pode provocar efeitos neurotóxicos em curto prazo, os quais podem ser exacerbados caso a exposição seja prolongada.(AU)

Fipronil is a selective-toxicity insecticide widely used in agriculture and veterinary medicine. However, there are reports of neurotoxic effects of this substance, causing damages to vertebrates. We evaluated the locomotor activity, motor coordination and the activity of brain acetylcholinesterase in rats exposed to fipronil. Adult male Wistar rats (n= 15) received fipronil at a dose of 30mg/kg orally for 15 days; the Control group (n= 15) was treated with oral solution in the same period. On the 16th day of experimentation, the animals were submitted to the open field arena test and hole-board test. On the 17th day, they were anesthetized and euthanized, and organs were collected, and subsequently brain AChE was evaluated. Exposure to fipronil yielded no significant changes on motor coordination and locomotor activity but caused significant inhibition of brain acetylcholinesterase activity. These findings suggest that fipronil may cause short-term neurotoxic effects, which may be exacerbated if exposure is prolonged.(AU)

Effect of different test indicators and observation periods in contextual fear conditioning test on detection of behavioral efficacy of 5XFAD transgenic mice / 上海交通大学学报（医学版）

Objective • To explore whether different test indicators and observation periods in contextual fear conditioning test affect the detection effectiveness of learning and memory ability of 5XFAD transgenic mice. Methods • Twelve 4-month-old female 5XFAD transgenic progeny mice and 14 4-month-old female LM progeny mice were selected, which were produced by crossing male 5XFAD transgenic mice and female C57BL/6 mice, to conduct open field test and contextual fear conditioning test in succession. Total distance and velocity in open field test and average motion index in the first 60 s of training stage in contextual fear conditioning test of the two groups of mice were used to evaluate the difference of locomotor activity. Besides, the first 180 s, 181-360 s and the first 300 s of testing stage for observation were selected to evaluate the selection effects on percent freeze and activity suppression ratio. Then further investigation was launched to explore the effects of different observation periods on the detection effectiveness of percent freeze and activity suppression ratio. Results • The differences of total distance and total velocity of the two groups of mice in open field test were not statistically significant, however the average motion index in the first 60 s of training stage in contextual fear conditioning test of 5XFAD transgenic mice was significantly higher than that of LM mice (P=0.027). The comparison of percent freeze among the three groups of observation periods of LM mice had significant difference (both P<0.05), while there was no statistical significance in activity suppression ratio. The comparisons of percent freeze and activity suppression ratio among the three groups of observation periods of 5XFAD mice had no significant difference. The differences of percent freeze between 5XFAD mice and LM mice was not statistically significant during the three observation periods. However, the activity suppression ratio of 5XFAD mice was significantly higher than that of LM mice in the first 180 s (P=0.038), in the other two observation periods the difference of activity suppression ratio between the two groups of mice was not statistically significant. Conclusion • The average motion index detected in training stage in contextual fear conditioning test is more sensitive than total distance and total velocity detected in open field test for evaluating locomotor activity of 5XFAD mice. In contextual fear conditioning test, different observation periods have effects on the value of percent freeze provided by single strain of mice, while the value of activity suppression ratio remains unaffected. Activity suppression ratio is more precise than percent freeze to reflect the cognitive deficiency of 5XFAD mice. It is more accurate to select the first 180 s of testing stage for observation.

Effects of Guilingji on serum metabolites in D-galactose-induced aging in rats / 药学学报

This work investigates the effects of Guilingji (GLJ) on D-galactose-induced aging and changes in serum metabolites by UHPLC-Q exactive orbitrap-MS in rats. The rat model of aging by subcutaneous injection of D-galactose (300 mg·kg-1) was used to analyze the effect of different concentrations of GLJ (37.5, 75, 150 mg·kg-1) on an open field test in aging rats. Rat serum was collected after 8 weeks and subjected to LC-MS to analyze the anti-aging effect of GLJ. Animal experimentation was approved according to the Committee on the Ethics of Animal Experiments of Shanxi University (SXULL2014032). GLJ significantly improved the autonomous activity of rats. Compared with the control group, 23 metabolites in the treated group changed significantly, involving three main pathways. The group that was given GLJ had altered regulation of 4 serum metabolites in two pathways. Our results indicate that GLJ can delay aging behavior in rats; the mechanism of this anti-ageing effect remains to be determined.

Evaluation of anxiolytic properties of BacoMind extract of plant Bacopa monnieri Linn. in comparison with diazepam in rodent model

Background: Anxiety is a state characterized by somatic, emotional, cognitive, and behavioral components, associated with significant disability. The pharmacotherapy for anxiety remains limited for achievable safety and tolerability of the medicines. Benzodiazepines use associated with side effects like psychomotor impairment and addiction liability. Due to the ADRs associated with antianxiety drugs, the drug trials have focused on screening herbal medicines that are reportedly used in the treatment of anxiety and which have minimal side effects.Methods: The anxiolytic activity was examined by using the elevated plus maze (EPM) and open field test (OFT), forty Albino wistar strain rats of both sex of weighing 120 to 200 g were divided into four groups of ten rats each.. Group 1 received vehicle (normal saline); group 2 received diazepam (1 mg/kg); groups 3 and 4 received BacoMind�, 30 and 60 mg/kg oral, respectively.Results: Rats treated with diazepam (1 mg/kg, p.o.) showed significant (p<0.001) increase in the percentage of open arms entries and time spent whereas, in closed arm the number of entries and time spent were significantly (p<0.05) decreased. Intraperitonial administration of BacoMind� extract of plant Bacopa monnieri Linn. exhibited significant (p<0.05) increase in the number of open arm entries and time spent with significant (p<0.05) reduction in number of entries and time spent in the closed arm as compared to group 1. BacoMind� treated rats also produced significant increase in the number of rearings (p<0.05), assisted rearings and number of squares crossed (p<0.01).Conclusions: BacoMind� extract of plant Bacopa monnieri Linn possess significant anxiolytic activity in the rats. It can be a promising anxiolytic agent.

In-Vivo Study on Anxiolytic Effects of Hydroalcoholic Extract of Agaricus blazei Murill

Background: Anxiety involved panic attacks either having or not having social fear, social anxiety disorder, generalized anxiety disorder as well as separation anxiety disorder is known to be marked mental diseases. It is related to high medical cost and a significant load of disease. Agaricus blazei Murill (AbM) is a mushroom and possesses immunemodulating and antimicrobial effects both in-vivo and in-vitro and as well as it has been used to treat cancer, hepatitis, dermatitis, and hyperlipidemia traditionally. Method: In this experiment evaluation of anxiolytic effect of AbM on mice has been done by using Elevated Plus Maze test, open field test and motor co-ordination test by rotarod. Mice (Mus musculus) weighing 22-25 grams, were divided into 4 groups (n=6). Oral administration of hydro-alcoholic extract of AbM was utilized in 2 doses i.e. 136.5 mg/kg and 273 mg/kg. Group, I received vehicle (distilled water 10 ml/kg), p.o. Group II received standard (diazepam 1 mg/kg), i.p. Group III and IV orally received hydro-alcoholic extract of AbM (136.5 mg/kg and 273 mg/kg, respectively). Result: In Elevated Plus Maze test, oral administration of hydro-alcoholic extract of AbM (136.5 mg/kg and 273 mg/kg, respectively) exhibited significant (p<0.01) elevation in the percentage of number of open arm entries (48.0 ± 1.1% and 48.93 ± 2.1% respectively) and time spent in open arm (14.92 ± 1.9% and 84.17 ± 2.4%). Conclusion: Hence it is concluded that hydro-alcoholic extract of AbM can be a new therapeutic agent to treat anxiety.

A comparative analysis of anxiolytic activity of Arnica montana and alprazolam in rats using open field test

Background: Anxiety affects around 7.3% of the total population worldwide. Benzodiazepines are preferred anxiolytic agents and are still frequently used in spite of the side effect profile including muscle relaxation, memory disturbances, sedation, physical dependence. Arnica montana, a traditional herb is known to possess significant anxiolytic effect at the dose of 100mg/kg. In this study, Arnica montana has been compared for the first time with alprazolam, a most commonly used anxiolytic drug.Methods: Forced swim test was used to induce anxiety. Anxiolytic action of study drugs which were given orally, was evaluated using Open field test (OFT) in healthy wistar rats of either sex. Behavior of rats, locomotion and number of squares crossed was recorded. Rats were divided into four groups with eight rats in each group. Study groups were Group I Control; Group II Alprazolam 0.08mg/kg; Group III Arnica montana extract (AME) 100mg/kg; Group IV AME + Alprazolam group 100mg/kg+0.08mg/kg. Statistical analysis was done using ANOVA followed by Tukey抯 test (p<0.05).Results: Increase in frequency of rearing was significant (p<0.05) in AME group and highly significant (p<0.001) in Alprazolam and combination group in comparison to control. Decrease in frequency of grooming was highly significant (p<0.001) in Alprazolam and combination group. AME also showed significant (p<0.05) decrease in grooming activity.Conclusions: Arnica montana extract showed anxiolytic activity and can be used as an add on drug after further studies and validation in the treatment of anxiety disorders.

Measurement and analysis of the behavioral changes of Rncat congenital cataract mice / 中国比较医学杂志

Objective To measure and analyze the behavioral changes of Rncat congenital cataract mice. Methods Normal BALB/c mice and KM mice were used as control group,and inbred and random mated Rncat congenital cataract mice were used as experimental group. Behavioral tests, including the open field test, coat-hanger test, forced swimming test,and tail suspension test,were conducted on the mice. Results Compared with the inbred Rncat congenital cataract mice,the residence time in the open field test,the immobility time in the forced swimming test and tail suspension test of the BALB/c mice, randomly-mated Rncat congenital cataract mice and KM mice were significantly different. Conclusions There are certain differences in behavioral performance between the Rncat congenital cataract mice and the other mice. Our findings may provide a useful reference for future researchers.

Protein Kinase C Activity and Delayed Recovery of Sleep-Wake Cycle in Mouse Model of Bipolar Disorder

OBJECTIVE: Previous studies reported the delayed recovery group after circadian rhythm disruption in mice showed higher quinpiroleinduced locomotor activity. This study aimed to compare not only Protein Kinase C (PKC) activities in frontal, striatal, hippocampus and cerebellum, but also relative PKC activity ratios among brain regions according to recovery of circadian rhythm. METHODS: The circadian rhythm disruption protocol was applied to eight-week-old twenty male Institute Cancer Research mice. The circadian rhythm recovery patterns were collected through motor activities measured by Mlog system. Depressive and manic proneness were examined by forced swim test and quinpirole-induced open field test respectively. Enzyme-linked immunosorbent assay was employed to measure PKC activities. RESULTS: The delayed recovery group presented greater locomotor activities than the early recovery group (p=0.033). The delayed recovery group had significantly lower frontal PKC activity than the other (p=0.041). The former showed lower frontal/cerebellar PKC activity ratio (p=0.047) but higher striatal/frontal (p=0.038) and hippocampal/frontal (p=0.007) PKC activities ratios than the latter. CONCLUSION: These findings support potential mechanism of delayed recovery after circadian disruption in bipolar animal model could be an alteration of relative PKC activities among mood regulation related brain regions. It is required to investigate the PKC downstream signaling related to the delayed recovery pattern.

Reliability and validity of free software for the analysis of locomotor activity in mice / 영남의대학술지

BACKGROUND: Kinovea software that tracking semi-automatically the motion in video screen has been used to study motion-related tasks in several studies. However, the validation of this software in open field test to assess locomotor activity have not been studied yet. Therefore, this study aimed to examine the reliability and validity of this software in analyzing locomotor activities.METHODS: Thirty male Institute Cancer Research mice were subjected in this study. The results examined by this software and the classical method were compared. Test-retest reliability and inter-rater reliability were analyzed with Pearson's correlation coefficient and intraclass correlation coefficient (ICC). The validity of this software was analyzed with Pearson's correlation coefficient.RESULTS: This software showed good test-retest reliability (ICC=0.997, 95% confidence interval [CI]=0.975–0.994, p < 0.001). This software also showed good inter-rater reliability (ICC=0.987, 95% CI=0.973–0.994, p < 0.001). Furthermore, in three analyses for the validity of this software, there were significant correlations between two methods (Pearson's correlation coefficient=0.928–0.972, p < 0.001). In addition, this software showed good reliability and validity in the analysis locomotor activity according to time interval.CONCLUSION: This study showed that this software in analyzing drug-induced locomotor activity has good reliability and validity. This software can be effectively used in animal study using the analysis of locomotor activity.

Effects of Chaihu Shugan San on Autonomic Behaviors and Spatial Learning- memory Abilities of Rats Treated with Stress for Different Time / 广州中医药大学学报

Objective To observe the effects of stress treatment for different time on autonomic behaviors and spatial learning-memory abilities of rats and to investigate the therapeutic efficacy of Chaihu Shugan San(CSS). Methods Seventy-five 8-week-old Wistar rats were randomly divided into blank control group, model control group, and low-, middle-, and high- dose CSS groups, 15 rats in each group. Chronic multi-stress model was set up. The rat body weight in various groups was measured. The autonomic behaviors of rats were observed by open field test, and the abilities of spatial learning-memory of rats were examined by Morris water maze test. Results (1)On modeling day 20, 30, the model control group had lighter body weight than the blank control group (P 0.05). (2)Open field test results showed as follows:Compared with the blank control group, the total distance and central-area distance were shortened (P 0.05). Conclusion The chronic stress may decrease the excitability, reduce autonomic behaviors, and injure spatial learning and memory abilities of rats, the effect being positively correlated with the modeling time. And CSS has an effect on improving the above indexes, in particular the middle-and high-dose of CSS.

Comparison of the behavior characteristics in SHR, WKY and SD rat models of attention deficit/hyperactivity disorder / 中国实验动物学报

Objective To compare the differences in behavior characteristics among SHR, WKY and SD rat models of attention deficit/hyperactivity disorder (ADHD), and explore an ideal control model of SHR rats.Methods Using open field test to analyze the rat movement distance, speed, wearing numbers and the number of grooming to evaluate the spontaneous movement in SHR, WKY and SD rats.Using the Morris water maze to test the learning and memory ability among the three rat groups.Results The result of open field test showed that the SHR rats had significantly increased (P< 0.01) total amount of exercise, average speed and wearing numbers than WKY and SD rats.Compared with the WKY rats, SD rats had a significantly higher movement distance (P< 0.01), slightly higher movement speed and wearing number (P< 0.05).In the Morris water maze hidden platform period test, the SD rats had a significantly longer latency than the SHR rats (P< 0.05).SD rats showed longer latency distance on the first, third and fourth days of training, as compared with the SHR rats (P< 0.05 or P< 0.01).Compared with the WKY group, SD rats showed a shorter latency distance in each training time (P< 0.05 or P< 0.01).In the probe trial period, the SD rats showed shorter time and distance ratio to the target quadrant than SHR rats (P< 0.05), while significantly longer than the WKY rats (P< 0.05 or P< 0.01).Conclusions There are significant behavioral differences between SHR and WKY rats, showing certain disadvantages in comparison of the two types of rats.To add SD rats as a control group for SHR rats can improve the comparability of behavior characteristics of SHR rats, and to get more objective evaluation of the behavior characteristics of SHR rats.

Effect of maternal separation stress on behavior of neonatal rd mice / 中国比较医学杂志

Objective To evaluate the effect of maternal separation stress on the behavior of neonatal rd mice.Methods Neonatal rd mice were divided into maternal separation (MS) group (n=9) and control group (n=9).MS-stress was induced in the MS group by 4-hour-separation per day for 28 days.Open field test,elevated plus maze test,forced swim test and tail suspension test were used to evaluate the anxiety-like and depression-like behavior of the neonatal rd mice.Results The stay time and distance travelled of MS group in the central zone were 0.88％ and 28.17±5.65 cm,respectively,significantly shorter than that of the control group (2.61％,109.9±9.79 cm.P =0.04,P =0.001).Compared with the control group,the stay time in open arms of the MS group was significantly decreased (P<0.01),while the immobility time in forced swim test and tail suspension test of the MS group were 126.5±10.22 s and 21.56±6.83 s,significantly longer than that of the control group (77.75±16.83 s,P =0.02,7.37±3.22 s,P =0.03).Conclutions The 28-day maternal separation stress can significantly increase the anxiety-like and depression-like behavior in neonatal rd mice.

Study on the correlation between the copy number of mitochondrial DNA of peripheral blood leukocytes in traumatic brain injury and the degree of neurologic impairment in rats / 中华行为医学与脑科学杂志

Objective To explore the correlation between the changes of mitochondrial DNA (mtDNA) copy number of peripheral blood leukocytes and the degree of neurological impairment after traumatic brain injury (TBI).Methods A total of 40 Sprague Dawley rats were randomly divided into 4 groups:control group (n=10),mild TBI group (n=10),moderate TBI group (n=10) and severe TBI group (n=10).The cortical impact injury method to construct TBI rat model of different damage degree.The neurological score (mNSS,screen test,open field test) after TBI 24 h,48 h,72 h was performed and the orbital venous plexus blood genomic DNA was extracted.The real-time PCR method to measure the relative mitochondrial DNA copy number.After the experiment,the rats were euthanized,and the brain tissue was stained with hematoxylin-eosin staining(HE).Results There were significant differences in the HE staining findings of brain tissue pathology (P＜ 0.05).Each group of rats with brain injury after peripheral blood mtDNA copy number in 24 h (9.63±3.62,P＜0.05) and 48 h (9.80±3.58,P＜0.05) increased,began to decline at 72 h (4.97±2.68,P＜0.05).The rats mNSS scores were related with the mtDNA copy number after TBI 24 h (r=0.578,P＜0.05) and 48 h (r=0.559,P＜0.05),and not related to TBI 72 h (r=0.487,P＞0.05).The rats screen test scores were related with the mtDNA copy number after TBI 24 h (r=0.573,P＜0.05) and 48 h (r =0.501,P＜0.05),and not related to TBI 72 h (r=0.273,P＞0.05).The rats level scores of open field test were negatively correlated with the mtDNA copy number after TBI24 h (r=-0.662,P＜0.05) and 48 h (r=-0.507,P＜0.05),and not negatively correlated to TBI 72 h (r=-0.410,P＞0.05).The rats vertical scores of open field test were negatively correlated with the mtDNA copy number after TBI 24 h (r=-0.662,P＜0.05)and 48 h (r =-0.607,P＜ 0.05),and not negatively correlated to TBI 72 h (r =-0.141,P＞ 0.05).Conclusion TBI is related with the copy of early peripheral white blood cell number and mtDNA of rat nerve function damage,and mtDNA copy number of peripheral white blood cell may become a clinical evaluation of TBI neural function damage degree of a potential biomarker.