The prevention of engram interference, pattern separation, flexibility, cognitive coordination and spatial navigation are usually studied separately at the behavioral level. Impairment in executive functions is often observed in patients suffering from schizophrenia. We have designed a protocol for assessing these functions all together as behavioral separation. This protocol is based on alternated or sequential training in two tasks testing different hippocampal functions (the Morris water maze and active place avoidance), and alternated or sequential training in two similar environments of the active place avoidance task. In Experiment 1, we tested, in adult rats, whether the performance in two different spatial tasks was affected by their order in sequential learning, or by their day-to-day alternation. In Experiment 2, rats learned to solve the active place avoidance task in two environments either alternately or sequentially. We found that rats are able to acquire both tasks and to discriminate both similar contexts without obvious problems regardless of the order or the alternation. We used two groups of rats, controls and a rat model of psychosis induced by a subchronic intraperitoneal application of 0.08mg/kg of dizocilpine (MK-801), a non-competitive antagonist of NMDA receptors. Dizocilpine had no selective effect on parallel/sequential learning of tasks/contexts. However, it caused hyperlocomotion and a significant deficit in learning in the active place avoidance task regardless of the task alternation. Cognitive coordination tested by this task is probably more sensitive to dizocilpine than spatial orientation because no hyperactivity or learning impairment was observed in the Morris water maze.

• Klíčová slova
• Active place avoidance, Context alternation, Dizocilpine, Morris water maze, Schizophrenia, Task alternation,
• MeSH
• analýza rozptylu MeSH
• antagonisté excitačních aminokyselin toxicita   MeSH
• bludiště - učení účinky léků   MeSH
• dizocilpinmaleát toxicita   MeSH
• krysa rodu Rattus MeSH
• lokomoce účinky léků   MeSH
• modely nemocí na zvířatech MeSH
• poruchy učení chemicky indukované   patofyziologie   MeSH
• potkani Long-Evans MeSH
• reakční čas účinky léků   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
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• antagonisté excitačních aminokyselin MeSH
• dizocilpinmaleát MeSH

The active place avoidance task is used in the research of spatial cognition. Rats are trained on a rotating arena to avoid an aversive stimulus delivered in a part of the room while being transported toward it by the arena rotation. The task tests the ability of rats to navigate with respect to distal cues in the room and to ignore confusing cues on the arena. The demand for cue segregation makes the task suitable for studying neural mechanisms responsible for cognitive coordination. An incidental observation made in our laboratory implied that overtrained rats may be able to solve the task without the room-bound cues. The aim of this study was to test this observation. The room-bound cues were hidden by switching off the lights. Rats trained only in darkness did not learn the task at all. Rats that were initially pre-trained in light performed considerably better. In a few exceptional dark sessions they even reached the level of performance observed in light. The rats needed the aversive stimuli to keep off the to-be-avoided sector. Without them, they continued their behavior, but with no spatial relationship to the to-be-avoided sector. We conclude that rats are able to solve the place avoidance task without the room-bound cues, but not as efficiently as in their presence.

• Klíčová slova
• Avoidance behavior, Cognitive coordination, Idiothetic navigation, Spatial behavior,
• MeSH
• elektrický šok MeSH
• plnění a analýza úkolů MeSH
• podněty * MeSH
• potkani Long-Evans MeSH
• prostorové učení * MeSH
• psychologické testy MeSH
• tma MeSH
• učení vyhýbat se * MeSH
• zraková percepce MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A modified model of the arena described by Bures et al. (Bures J, Fenton AA, Kaminsky Y, Zinyuk L. Place cells and place navigation, Proc. Natl. Acad. Sci. USA. 1997a;94:343-350) was applied to the place learning of adult male rats in two different avoidance paradigms. In the passive avoidance task rats exploring a stationary circular arena had to avoid a 60 degrees sector entering of which was punished by mild footshocks. Intramaze as well as extramaze cues could be used for adequate solution of this task. In the active avoidance paradigm rats were trained to avoid a room frame defined sector (e.g. North-East) of a slowly rotating arena the movement of which forced the animals to rely on extramaze cues and to ignore intramaze information. Rats had to find an active solution of the task since otherwise they were passively transported into the room frame defined punished zone. The suitability of these tasks for testing spatial abilities of rats is discussed.

• MeSH
• elektrický šok MeSH
• krysa rodu Rattus MeSH
• paměť fyziologie   MeSH
• podněty MeSH
• potkani Long-Evans MeSH
• rotace MeSH
• učení vyhýbat se * MeSH
• vnímání prostoru fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Dry arenas are a convenient tool for assessing the spatial navigation abilities of rodents. In this paper, mice must avoid a punished sector of a dry arena from which they are expelled by a puff of compressed air. The position of the punished sector is defined relative to the coordinate system of the room. In a stable environment the mice can use both extramaze and intramaze landmarks to orient themselves accurately. However, when the shock area is defined by extramaze landmarks, continuous rotation of the arena at 1 rpm makes it impossible to solve the avoidance task using arena-based cues or idiothesis. The avoidance can only be solved by paying attention to extramaze cues. Our protocol tested spatial abilities on stable and rotating arenas. The acquisition of the task was manifested under both conditions by a significant improvement of performance within the first session (short-term memory component) and at the beginning of the 24-h delayed second session (long-term memory component).

• MeSH
• bludiště - učení fyziologie   MeSH
• chování zvířat fyziologie   MeSH
• mozek fyziologie   MeSH
• myši MeSH
• neuropsychologické testy * MeSH
• orientace fyziologie   MeSH
• paměť fyziologie   MeSH
• psychomotorický výkon fyziologie   MeSH
• učení vyhýbat se fyziologie   MeSH
• vnímání prostoru fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

This paper assesses the contribution of hippocampus to the spatial orientation of Long-Evans rats in a new place avoidance task. The animals learn to avoid a mild footshock in a segment of a rotating arena. Since the punished region is defined in the coordinate system of the stationary room the subject is forced to move away from the prohibited segment even if it is immobile. After bilateral injection of tetrodotoxin (5 ng in 1 microl of saline) into the dorsal hippocampus rats were not able to avoid the punished place while a similar injection of saline did not affect performance. The results suggest the task is suitable for assessing the hippocampus-dependent spatial abilities of laboratory rodents.

• MeSH
• hipokampus účinky léků   fyziologie   MeSH
• katetrizační ablace metody   MeSH
• krysa rodu Rattus MeSH
• orientace účinky léků   fyziologie   MeSH
• potkani Long-Evans MeSH
• tetrodotoxin farmakologie   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
• Názvy látek
• tetrodotoxin MeSH

The active place avoidance task is used for testing cognitive abilities in rats. A rat, placed on a rotating circular arena, should avoid an unmarked sector defined with respect to stable extra-arena cues. We hypothesized that the inertial stimuli generated by the arena rotation may contribute to the performance in the task. These stimuli provide permanent information to the rat concerning changes in its position with respect to the extra-arena cues, it means to the reference frame in which the to-be-avoided sector is defined. To test the hypothesis, we trained one group of rats on a stable arena while extra-arena cues rotated around the arena. This eliminated the inertial stimuli generated by the arena rotation while preserving other aspects of the task. Six out of seven rats from this group did not learn this modified task. The remaining rat learned it equally well as rats from a control group learned the standard active place avoidance task. After six days of training, we changed the tasks between the groups. The control rats solved the modified task as well as the standard task. We conclude that the inertial stimuli generated by the arena rotation are important for acquisition of the active place avoidance task but not for performance once the task has been mastered. We suggest that rats must perceive the distal extra-arena cues as stable in order to associate the position of the to-be-avoided sector with these cues.

• MeSH
• analýza rozptylu MeSH
• kognice fyziologie   MeSH
• krysa rodu Rattus MeSH
• orientace fyziologie   MeSH
• podněty MeSH
• potkani Long-Evans MeSH
• prostorové chování fyziologie   MeSH
• rotace MeSH
• učení vyhýbat se fyziologie   MeSH
• vnímání prostoru 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.

• Klíčová slova
• Carousel maze, Cognitive coordination, Memantine, Rats, Spatial place avoidance,
• 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
• Názvy látek
• antagonisté excitačních aminokyselin MeSH
• memantin MeSH
• receptory N-methyl-D-aspartátu MeSH

Neurotransmitter substrate of spatial cognition belongs to current topics in behavioral neuroscience. The present study examined the effects of serotonin depletion with p-chlorophenylalanine on learning of rats in active place avoidance, a spatial task requiring allothetic mapping and cognitive coordination and highly dependent upon hippocampus. Serotonin depletion transiently increased locomotor activity in response to footshocks, but it did not change the avoidance efficiency measured by three spatial parameters. These results suggest that serotonin neurotransmission is not crucial for cognitive coordination and allothetic learning, i.e. the processes, which are crucial for active place avoidance performance.

• MeSH
• antagonisté serotoninu farmakologie   MeSH
• fenklonin farmakologie   MeSH
• kognice účinky léků   fyziologie   MeSH
• krysa rodu Rattus MeSH
• pohybová aktivita účinky léků   fyziologie   MeSH
• potkani Long-Evans MeSH
• serotonin metabolismus   MeSH
• učení vyhýbat se účinky léků   fyziologie   MeSH
• vnímání prostoru 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
• Názvy látek
• antagonisté serotoninu MeSH
• fenklonin MeSH
• serotonin MeSH

It is well known that communication between the medial prefrontal cortex (mPFC) and the ventral hippocampus (vHPC) is critical for various cognitive and behavioral functions. However, the exact role of these structures in spatial coordination remains to be clarified. Here we sought to determine the involvement of the mPFC and the vHPC in the spatial retrieval of a previously learned active place avoidance task in adult male Long-Evans rats, using a combination of unilateral and bilateral local muscimol inactivations. Moreover, we tested the role of the vHPC-mPFC pathway by performing combined ipsilateral and contralateral inactivations. Our results showed not only bilateral inactivations of either structure, but also the combined inactivations impaired the retrieval of spatial memory, whereas unilateral one-structure inactivations did not yield any effect. Remarkably, muscimol injections in combined groups exerted similar deficits, regardless of whether the inactivations were contralateral or ipsilateral. These findings confirm the importance of these structures in spatial cognition and emphasize the importance of the intact functioning of the vHPC-mPFC pathway.

• Klíčová slova
• active place avoidance, hippocampo-prefrontal pathway, muscimol, rotating arena, spatial memory,
• MeSH
• hipokampus * MeSH
• krysa rodu Rattus MeSH
• muscimol farmakologie   MeSH
• potkani Long-Evans MeSH
• prefrontální mozková kůra MeSH
• prostorová paměť * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• muscimol MeSH

Animal navigation to hidden goals (place navigation) ranks among the most intensively studied types of behaviour because it requires brain representations of environments in the form of cognitive maps, demonstrated to depend on hippocampal function. Intact function of muscarinic receptors in the brain was originally assumed to be crucial for place navigation, however, recent studies using non-spatial pretraining demonstrated that animals with central blockade of muscarinic acetylcholine receptors can also learn and retrieve spatial memory engrams. In the present study we addressed whether navigation in the active allothetic place avoidance (AAPA) task, which requires animals to separate spatial stimuli into coherent representations and navigate according to the representation relevant for the task, is dependent on intact muscarinic receptors in the brain. We studied the effect of three doses of scopolamine (0.5, 1.0 and 2.0mg/kg) administered 20 min prior to training on the retention of the AAPA and re-acquisition of the AAPA in a new environment. The dose of 2.0mg/kg was found to impair both AAPA retention and re-acquisition of the AAPA in a new environment, whereas the 1.0mg/kg dose only impaired the reinforced retention of AAPA. It is concluded that, unlike navigation in classic paradigms, efficient orientation in the AAPA task is critically dependent on muscarinic receptors in the brain.

• MeSH
• analýza rozptylu MeSH
• antagonisté muskarinových receptorů aplikace a dávkování   MeSH
• bludiště - učení účinky léků   MeSH
• časové faktory MeSH
• chování zvířat účinky léků   MeSH
• krysa rodu Rattus MeSH
• pohybová aktivita účinky léků   MeSH
• potkani Long-Evans MeSH
• prostorové chování účinky léků   MeSH
• retence (psychologie) účinky léků   MeSH
• rozpomínání účinky léků   MeSH
• rozvrh dávkování léků MeSH
• skopolamin aplikace a dávkování   MeSH
• učení vyhýbat se účinky léků   MeSH
• vnímání prostoru účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• antagonisté muskarinových receptorů MeSH
• skopolamin MeSH