Schizophrenia is severe neuropsychiatric disease, which is commonly accompanied not only by positive or negative symptoms, but also by cognitive impairment. To study neuronal mechanisms underlying cognitive distortions and mechanisms underlying schizophrenia, animal pharmacological models of cognitive symptoms are commonly used. Between various cognitive impairments in schizophrenia patients, disturbed time perception has often been reported. Here, we examined temporal and spatial cognition in a modified Carousel maze task in the animal model of schizophrenia induced by non-competitive NMDA-receptor antagonists MK-801. Male Long-Evans rats (n = 18) first learned to avoid the aversive sector on a rotating arena in both dark and light intervals. We verified that during dark, rats used temporal cues, while during light they relied predominantly on spatial cues. We demonstrated that the timing strategy depends on the stable rotation speed of the arena and on the repositioning clues such as aversive stimuli. During testing (both in light and dark intervals), half of the rats received MK-801 and the control half received saline solution. We observed dose-dependent disruptions of both temporal and spatial cognition. Namely, both doses of MK-801 (0.1 and 0.12 mg/kg) significantly impaired timing strategy in the dark and increased locomotor activity. MK-801 dose 0.1 mg/kg, but not 0.12, also impaired spatial avoidance strategy in light. We found that the timing strategy is more sensitive to NMDA antagonist MK-801 than the spatial strategy. To conclude, a modified version of the Carousel maze is a useful and sensitive tool for detecting timing impairments in the MK-801 induced rodent model of schizophrenia.
- MeSH
- antagonisté excitačních aminokyselin aplikace a dávkování farmakologie MeSH
- bludiště - učení účinky léků MeSH
- chování zvířat účinky léků MeSH
- dizocilpinmaleát aplikace a dávkování farmakologie MeSH
- kognitivní dysfunkce chemicky indukované patofyziologie MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- potkani Long-Evans MeSH
- schizofrenie chemicky indukované MeSH
- učení vyhýbat se účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Neural components enabling flexible cognition and behavior are well-established, and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. However, dense projections from the ventral hippocampus (vHPC) alter the functioning of the medial PFC (mPFC). Dysfunctional hippocampo-prefrontal connectivity negatively affects the integrity of flexible cognition, especially in patients with schizophrenia. In this study, we aimed to test the role of the vHPC and mPFC in a place avoidance task on a rotating arena using two spatial flexibility task variants - reversal learning and set-shifting. To achieve this, we inactivated each of these structures in adult male Long-Evans rats by performing bilateral local muscimol (a GABAA receptor agonist) injections. A significantly disrupted performance was observed in reversal learning in the vHPC-inactivated, but not in the mPFC-inactivated rats. These results confirm the notion that the vHPC participates in some forms of behavioral flexibility, especially when spatial cues are needed. It seems, rather unexpectedly, that the mPFC is not taxed in these flexibility tasks on a rotating arena.
- MeSH
- hipokampus účinky léků fyziologie MeSH
- krysa rodu rattus MeSH
- muscimol farmakologie MeSH
- pozornost účinky léků fyziologie MeSH
- prefrontální mozková kůra účinky léků fyziologie MeSH
- prostorové vidění účinky léků fyziologie MeSH
- receptory GABA-A - agonisté farmakologie MeSH
- reverzní učení účinky léků fyziologie MeSH
- učení vyhýbat se účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Neural components enabling flexible cognition and behavior are well-established, and depend mostly on proper intercommunication within the prefrontal cortex (PFC) and striatum. However, dense projections from the ventral hippocampus (vHPC) alter the functioning of the medial PFC (mPFC). Dysfunctional hippocampo-prefrontal connectivity negatively affects the integrity of flexible cognition, especially in patients with schizophrenia. In this study, we aimed to test the role of the vHPC and mPFC in a place avoidance task on a rotating arena using two spatial flexibility task variants - reversal learning and set-shifting. To achieve this, we inactivated each of these structures in adult male Long-Evans rats by performing bilateral local muscimol (a GABAA receptor agonist) injections. A significantly disrupted performance was observed in reversal learning in the vHPC-inactivated, but not in the mPFC-inactivated rats. These results confirm the notion that the vHPC participates in some forms of behavioral flexibility, especially when spatial cues are needed. It seems, rather unexpectedly, that the mPFC is not taxed in these flexibility tasks on a rotating arena.
- MeSH
- hipokampus účinky léků fyziologie MeSH
- krysa rodu rattus MeSH
- muscimol farmakologie MeSH
- pozornost účinky léků fyziologie MeSH
- prefrontální mozková kůra účinky léků fyziologie MeSH
- prostorové vidění účinky léků fyziologie MeSH
- receptory GABA-A - agonisté farmakologie MeSH
- reverzní učení účinky léků fyziologie MeSH
- učení vyhýbat se účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Memory is related to the function of N-methyl-D-aspartate (NMDA) receptors. Depending on the dose, NMDA receptor antagonists (such as memantine or MK-801) can impair memory and/or cognitive as well as procedural functions, while they also can prevent the long-term toxic effects of over-excitation of these receptors in pathophysiological processes. There is an unresolved question of whether memantine at low doses could exert an acute pro-cognitive activity. A therapeutic dose of memantine was found to improve short-term spatial memory tested in the alternation version of active place avoidance in a Carousel Maze, whereas no data are available on long-term memory in various versions of place avoidance. In an effort to reconcile this issue, rats were administered memantine (5 mg/kg) 30 min before a training session and trained in two different versions of place avoidance. A control group received saline injections. In an active place avoidance task (hereby referred to as Room+Arena-), this place was fixed to distal room cues, whereas cues from the arena were misleading. Performance thus demanded the on-going segregation of information that engages cognitive coordination. Following the Room+Arena- training, rats were trained in another place avoidance task (hereby referred to as Arena+), which requires focusing on substratal and idiothetic cues from the arena. In this version, a to-be-avoided sector rotated along with the arena in darkness that hid the extramaze cues. The rats given memantine avoided better than the control rats in the Room+Arena- task. In the Arena+ task, both groups had problems with acquiring the task. Subsequently, memantine was withdrawn and both groups relearned Room+Arena- avoidance with a new sector position. In this task, no effect of groups was seen. In conclusion, memantine at a therapeutic dose improved performance in a task that required the segregation of spatial stimuli into coherent subsets.
- MeSH
- antagonisté excitačních aminokyselin farmakologie MeSH
- chování zvířat účinky léků MeSH
- krysa rodu rattus MeSH
- memantin farmakologie MeSH
- podněty MeSH
- potkani Wistar MeSH
- prostorová paměť účinky léků MeSH
- receptory N-methyl-D-aspartátu antagonisté a inhibitory MeSH
- učení vyhýbat se účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In this paper, we propose an integrated biologically inspired visual collision avoidance approach that is deployed on a real hexapod walking robot. The proposed approach is based on the Lobula giant movement detector (LGMD), a neural network for looming stimuli detection that can be found in visual pathways of insects, such as locusts. Although a superior performance of the LGMD in the detection of intercepting objects has been shown in many collision avoiding scenarios, its direct integration with motion control is an unexplored topic. In our work, we propose to utilize the LGMD neural network for visual interception detection with a central pattern generator (CPG) for locomotion control of a hexapod walking robot that are combined in the controller based on the long short-term memory (LSTM) recurrent neural network. Moreover, we propose self-supervised learning of the integrated controller to autonomously find a suitable setting of the system using a realistic robotic simulator. Thus, individual neural networks are trained in a simulation to enhance the performance of the controller that is then experimentally verified with a real hexapod walking robot in both collision and interception avoidance scenario and navigation in a cluttered environment.
- MeSH
- chování zvířat fyziologie MeSH
- chůze fyziologie MeSH
- kobylky fyziologie MeSH
- neuronové sítě (počítačové) MeSH
- řízené strojové učení MeSH
- robotika přístrojové vybavení MeSH
- učení vyhýbat se fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of this research was to assess the effect of soil contamination with titanium (Ti) and iron (Fe) at military sites in Ukraine using the avoidance and reproduction tests with Folsomia candida (springtail). The soil used for the tests was sampled in 2017 from Dolyna, Ivano-Frankivsk region, Ukraine from two plots, namely a contaminated and a control site. The sample site is a former military site previously used for tank training. At the control site mainly the concentrations of Ti and Fe were exceeded. The control soil was free from contamination. The avoidance test and reproduction test were conducted with the use of springtail species F. candida. The following nine levels of contamination with heavy metals were established: 1%, 1.5%, 5%, 10%, 15%, 25%, 50%, 75% and 100%. The duration of the avoidance test was 7 days, and that of the reproduction test was 28 days. Overall, the results show that the avoidance and reproduction tests with collembolans have the potential to be used as screening tools in an ecological risk assessment of heavy metals. In the avoidance test, the concentrations from 1.5 to 100% significantly decreased the number of F. candida in the contamination site in comparison to the control site. At the same time, avoidance was not observed in the first concentration (1%). According to the reproduction test, the negative effect on the number of F. candida juveniles was observed beginning at the 10% dose. The half maximal effective concentration (EC50) for the avoidance test was 50.12%, while that for the reproduction test was 22.39%. The contamination with heavy metals at the military areas indicated the short- and long-term toxicity risk on the springtail F. candida.
- MeSH
- členovci účinky léků MeSH
- hodnocení rizik MeSH
- látky znečišťující půdu toxicita MeSH
- ozbrojené síly MeSH
- rozmnožování účinky léků MeSH
- testy toxicity * MeSH
- titan toxicita MeSH
- učení vyhýbat se účinky léků MeSH
- železo toxicita MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Animals that do not provide parental care have to secure the survival of their offspring by ensuring a safe reproductive environment or smart timing tactics. Nocturnal spawning behaviour of many fish species is an example of the latter behaviour in the animal kingdom and is hypothesized to provide a survival advantage to the eggs spawned during the night. In order to test the efficiency of the smart timing tactics in a freshwater fish, a study was carried out of the interaction of the rheophilic spawner (asp Leuciscus aspius) and the predator of its drifting eggs (bleak Alburnus alburnus) using passive telemetry. According to a model based on acquired data, asp laid 63% of its eggs at night, while vision-oriented bleak was present in 92% of the time during the day. This study gives support to the predator avoidance hypothesis, which expects animals to reproduce in a period when the probability of offspring predation is at its lowest.
BACKGROUND: 6-chlorotacrine is a cholinesterase inhibitor showing good inhibitory potential, even better than parent compound tacrine, in vitro. Despite tacrine scaffold is broadly used for design and synthesis of novel compounds with anti-Alzheimer's potential, no in vivo effects have been investigated so far. Thus, basic toxicological and behavioural evaluation has been carried out throughout this study. METHODS: Maximum tolerated dose (MTD) and median lethal dose (LD50) were assessed in BALB/c mice and Wistar rats. Behavioural effects were observed in rats performing the multiple T-maze test, the water maze test and the step-through passive avoidance test. All outcomes were compared with the effects of parent compound - tacrine. RESULTS: The toxicity of 6-chlorotacrine was increased compared to tacrine with MTD 6.0/5.0 mg.kg-1 (i.m., male/female mice), 6.0/5.0 mg.kg-1 (i.p., male/female rats) and LD50 9.0 mg.kg-1 (male rats). At MTD doses, no histopathological changes and blood biochemistry abnormalities were observed except decreased plasma creatinine levels. 6-chlorotacrine showed good effects in the reversal of quinuclidinyl benzilate-induced amnesia. Best results were achieved at the dose of 1.8 mg.kg-1 (20% LD50) in the water maze test; the pro-cognitive effect was stronger than that of tacrine (5.2 mg.kg-1, 20% LD50). Other doses tested (0.9 mg.kg-1 and 2.7 mg.kg-1) showed similar effects as tacrine in the water maze, multiple T-maze and passive avoidance test. CONCLUSION: Observed effects predetermined 6-chlorotacrine as a potent parent compound for the synthesis of novel multifactorial drugs intended to the treatment of Alzheimer's disease. Even though 6- chlorotacrine showed in vivo beneficial effect with no signs of toxicity, further tests on the field of biochemistry and pharmacology are essential to disclose the exact mechanism of action, safety evaluation and the metabolic fate of the compound after the repeated administration.
- MeSH
- bludiště - učení účinky léků MeSH
- cholinesterasové inhibitory chemie farmakologie toxicita MeSH
- myši inbrední BALB C MeSH
- nootropní látky chemie farmakologie toxicita MeSH
- potkani Wistar MeSH
- preklinické hodnocení léčiv MeSH
- takrin analogy a deriváty chemie farmakologie toxicita MeSH
- učení vyhýbat se účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Corticotropin-releasing hormone (CRH) is involved in modification of synaptic transmission and affects spatial discrimination learning, i.e., affects the formation of memory in long-term aspect. Therefore, we have focused on CRH effect on short-term memory. We have used stress task avoidance (maze containing three zones: entrance, aversive, and neutral) and compared the behavior and short-term memory in wild-type mice and mice lacking CRH (CRH KO) experiencing one 120-min session of restraint stress. As control, non-stressed animals were used. As expected, the animals that experienced the stress situation tend to spend less time in the zone in which the restraint chamber was present. The animals spent more time in the neutral zone. There were significant differences in number of freezing bouts in the aversive and entrance zones in CRH KO animals. CRH KO control animals entered the neutral zone much more faster than WT control and spent more time immobile in the neutral zone than WT control. These data give evidence that lacking of CRH itself improves the ability of mice to escape away from potentially dangerous area (i.e., those in which the scent of stressed animal is present).
- MeSH
- hormon uvolňující kortikotropin nedostatek MeSH
- krátkodobá paměť fyziologie MeSH
- myši inbrední C57BL MeSH
- myši kmene 129 MeSH
- myši knockoutované MeSH
- myši MeSH
- psychický stres metabolismus psychologie MeSH
- učení vyhýbat se fyziologie MeSH
- úniková reakce fyziologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Cílem výzkumu bylo zmapovat vybrané faktory chování ovlivňujícího zdraví u dětí a mládeže v Pardubickém a Královéhradeckém kraji, které tvoří východočeský region. Respondenty se stalo celkem 664 žáků a studentů vybraných základních a středních škol. Výzkum byl realizován formou kvantitativního sběru dat, technikou dotazníku vlastní konstrukce se škálovými otázkami. Dotazník rizikového chování v dospívání mapuje rizikové faktory životního stylu dětí a mládeže. Jedná se konkrétně o kategorie záškoláctví a neplnění školních povinností, závislostní chování, agresivní chování včetně sebepoškozování, rizikové chování v oblasti reprodukčního zdraví a rizikové chování spojené s užíváním počítače a internetu. Příspěvek představuje výsledky vybraných kategorií rizikového chování včetně vzájemných vazeb. Výsledky ukázaly signifikantní souvislost mezi jednotlivými zkoumanými jevy u výzkumného souboru. Zajímavostí je rovněž stírání genderových rozdílů. Z hlediska pohlaví se ukázaly rozdíly pouze v agresivním chování a času stráveném na počítači či internetu. Obojí se jeví ve zvýšené míře u chlapců. Věk respondentů měl souvislost pouze se záškoláctvím, které v souvislosti s narůstajícím věkem klesá.
The aim of the study was to examine selected factors of health-related behaviour in children and youth in the Pardubice and Hradec Králové regions (which constitute East Bohemia). The participants were 664 pupils and were students of selected elementary and secondary schools. The research was carried out by means of quantitative data collection, using a questionnaire of our own design which included scale questions. The questionnaire of risk behaviour in adolescence investigates the risk factors of lifestyle in children and youth, i.e. specifically the category of truancy, neglecting school duties, addictive behaviour, aggressive behaviour including self-harm, reproductive health-related risk behaviour, and computer and internet use-related risk behaviour. The contribution presents results concerning the selected categories of risk behaviour, including their interrelations. The results demonstrate the significant relations among the individual examined phenomena in the research group. Low gender differences are also interesting. In terms of gender, there were differences only in aggressive behaviour and the time spent using a computer or the internet. Male pupils scored higher in both the mentioned variables. Respondents’ age was only related to truancy, which decreased as their age increased.
