Circular Open Field Research Articles

Organization of spontaneous spatial behaviors under dark conditions is unaffected in adult male and female long-Evans rats after moderate prenatal alcohol exposure.

Prenatal alcohol exposure can produce disruptions in a wide range of cognitive functions, but it is especially detrimental to spatial navigation. In open environments, rodents organize their spatial behaviors around centralized locations, termed home bases, from which they make circuitous and slow locomotor trips (progressions) into the rest of the environment. Open-field behaviors are organized even under darkened test conditions, suggesting a role for self-motion cues (vestibular, motor, etc.). The impact of moderate prenatal alcohol exposure (mPAE) on the organization of spontaneous open-field behaviors under darkened conditions has not been investigated. Here we tested adult female and male rats with mPAE or saccharin control exposure in a circular open field for 30 min in a testing room that was made completely dark. While general locomotion, as measured by reductions in travel distance and increased stop duration, decreased across the test session, the organization of these behaviors, as measured by stop duration, home base establishment, home base stability, progression accuracy, and scaling of peak speeds with progression length, did not differ between mPAE and saccharin control rats. Together, the findings strongly suggest that spontaneous movement organization in relation to self-motion cues remains intact in adult mPAE rats. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Sexually dimorphic organization of open field behavior following moderate prenatal alcohol exposure.

Prenatal alcohol exposure (PAE) can produce deficits in a wide range of cognitive functions but is especially detrimental to behaviors requiring accurate spatial information processing. In open field environments, spatial behavior is organized such that animals establish "home bases" marked by long stops focused around one location. Progressions away from the home base are circuitous and slow, while progressions directed toward the home base are non-circuitous and fast. The impact of PAE on the organization of open field behavior has not been experimentally investigated. In the present study, adult female and male rats with moderate PAE or saccharin exposure locomoted a circular high walled open field for 30minutes under lighted conditions. The findings indicate that PAE and sex influence the organization of open field behavior. Consistent with previous literature, PAE rats exhibited greater locomotion in the open field. Novel findings from the current study indicate that PAE and sex also impact open field measures specific to spatial orientation. While all rats established a home base on the periphery of the open field, PAE rats, particularly males, exhibited significantly less clustered home base stopping with smaller changes in heading between stops. PAE also impaired progression measures specific to distance estimation, while sex alone impacted progression measures specific to direction estimation. These findings support the conclusion that adult male rats have an increased susceptibility to the effects of PAE on the organization of open field behavior.

Sodium bicarbonate cotransporter NBCn1/Slc4a7 affects locomotor activity and hearing in mice

Despite a widespread expression pattern in the central nervous system, the role of the sodium bicarbonate cotransporter NBCn1/Slc4a7 has not been investigated for locomotor activity, emotion and cognition. Here, we addressed the behavioral consequences of NBCn1 knockout and evaluated hearing and vision that are reportedly impaired in an earlier line of NBCn1 knockout mice and may contribute to behavioral changes. In a circular open field, the knockout mice traveled a shorter distance, especially in the periphery of the chamber, than wildtype littermates. The knockout mice also traveled a shorter total distance in a home cage-like open field. Rearing and grooming behaviors were reduced. The knockout and control mice displayed similar time spent and number of open and closed arms in the elevated plus maze test, indicating negligible change in anxiety. In the Morris water maze test, both groups of mice learned the location of an escape platform within comparable time on the training trials and showed similar platform identification on the probe trial. The knockout mice maintained normal visual responses in the optokinetic drum and produced evoked potentials in response to light stimuli. However, these mice failed to produce auditory evoked potentials. qPCR revealed a robust expression of an alternatively transcribed NBCn1 variant in the knockout mouse retina. These results indicate that NBCn1 deletion leads to reduced locomotor activity in mice by affecting their exploratory behaviors or emotionality. The deletion also causes hearing loss, but its effect on vision varies between different lines of knockout mice.

Adopting a circular open-field layout in designing flexible manufacturing systems

ABSTRACT A new circular open field layout composed of a vehicle-based material handling system and multiple circular loops is proposed. The suggested layout offers more flexibility for high-mix low-volume production systems compared to other layouts as it maximizes the number of equidistant machines. A novel approach that integrates experimental design with computational modelling and statistical analysis was followed to study the proposed system. Forty experimental scenarios were generated using Face Centred Composite Design (FCCD) to numerically investigate the effect of layout, production quantity, variety and complexity on minimum production cost. To determine the minimum production cost in each experiment, a linear programming (LP) optimization model was formulated with layout dependent machine distance algorithm. The model solves for the optimum location of the machines and machine cell formations that minimizes the production cost. It considers material handling costs, alternative process routing, operations sequence, lot splitting, and machine costs. Furthermore, the cost was modeled using regression analysis to provide a quick estimate without the need to run computational intensive numerical models. Results reveal the effectiveness of the proposed layout with cost savings reaching 35% compared to traditional open field layout when product variety and complexity are increased.

Using Circular Open Field Thigmotaxis to Test Fermented Plant Extracts as Rat Repellents

We investigated the efficacy of five fermented plant extracts (kaffir lime, noni, garlic, chili and mint) as rat repellents, using circular open field thigmotaxis. Plants were fermented for 1, 3 and 5 days. Rats (Rattus rattus) were exposed to fermented plant extracts placed in the core zone (central area) of a circular open field. Rat behaviors in the field were observed for one hour and movements within the outer, middle and core zones of the field were recorded. Rats showed anxiety and aversion to the circular open field’s core zone. The average time (in minutes) that rats spent in the three zones was compared using a one-way ANOVA. Rats showed the highest aversion responses to noni and kaffir lime extracts. Calculation of thigmotactic ratios revealed that fermented noni and kaffir lime had higher scores than any of the other plants. Our results show that noni and kaffir lime could be used in rat repellent products, which would be low cost and environmental friendly.

Spontaneous locomotor activity of drosophila subobscura under controlled laboratory conditions

The aim of this research was to examine the temporal patterns of spontaneous locomotor activity in Drosophila subobscura virgin females and males from isofemale lines collected from beech and oak forests and maintained in controlled laboratory conditions for five full-sib inbreeding generations. The flies were monitored in a circular open field arena for 30 min in the morning (8:00 AM, 9:00 AM, 10:00 AM, 11:00 AM). The distance travelled and the mobility of the flies decreased along with the registration time, whereby the slowest decreasing was observed at 8:00 AM. Females showed a greater range of variability in both parameters compared to males. In addition, there was a greater range of variability in the locomotor activities of flies from the oak forest compared to the beech. These findings could be attributed to their specific genetic background.

Modeling Drosophila Positional Preferences in Open Field Arenas with Directional Persistence and Wall Attraction

In open field arenas, Drosophila adults exhibit a preference for arena boundaries over internal walls and open regions. Herein, we investigate the nature of this preference using phenomenological modeling of locomotion to determine whether local arena features and constraints on movement alone are sufficient to drive positional preferences within open field arenas of different shapes and with different internal features. Our model has two components: directional persistence and local wall force. In regions far away from walls, the trajectory is entirely characterized by a directional persistence probability, , for each movement defined by the step size, , and the turn angle, . In close proximity to walls, motion is computed from and a local attractive force which depends on the distance between the fly and points on the walls. The directional persistence probability was obtained experimentally from trajectories of wild type Drosophila in a circular open field arena and the wall force was computed to minimize the difference between the radial distributions from the model and Drosophila in the same circular arena. The two-component model for fly movement was challenged by comparing the positional preferences from the two-component model to wild type Drosophila in a variety of open field arenas. In most arenas there was a strong concordance between the two-component model and Drosophila. In more complex arenas, the model exhibits similar trends, but some significant differences were found. These differences suggest that there are emergent features within these complex arenas that have significance for the fly, such as potential shelter. Hence, the two-component model is an important step in defining how Drosophila interact with their environment.

The influence of static magnetic field (50 mT) on development and motor behaviour of Tenebrio (Insecta, Coleoptera)

Purpose: There is considerable concern about potential effects associated with exposure to magnetic fields on organisms. Therefore, duration of pupa-adult development and motor behaviour of adults were analyzed in Tenebrio obscursus and T. molitor after exposure to static magnetic field (50 mT).Material and methods: The experimental groups were: Control (kept 5 m from the magnets), groups which pupae and adults were placed closer to the North pole, or closer to the South pole of magnetic dipole. The pupae were exposed to the magnetic field until the moment of adult eclosion. The pupa-adult development dynamics were recorded daily. Subsequently, behaviour (distance travelled, average speed and immobility) of adults exposed to the magnetic field was monitored in a circular open field arena.Results: Static magnetic field did not affect pupa-adult developmental dynamic of examined Tenebrio species. Exposure to magnetic field did not significantly change motor behaviour of T. obscurus adults. The changes in the motor behaviour of T. molitor induced by static magnetic field were opposite in two experimental groups developed closer to the North pole or closer to the South pole of magnetic dipole.Conclusion: Static magnetic field (50 mT) did not affect on pupa-adult development dynamic of two examined Tenebrio species, but modulated their motor behaviour.

Behavioral effects of estradiol therapy in ovariectomized rats depend on the age when the treatment is initiated

Clinical studies suggest that aging may affect the neural outcome of estrogen therapy in postmenopausal women. In this study we have assessed whether age influences the behavioral outcome of estradiol therapy in rats. Animals were ovariectomized at 2 or 20 months of age. Immediately after ovariectomy animals were treated for 10 weeks with estradiol valerate or vehicle. Estradiol therapy decreased body weight in both young and older rats compared to animals injected with vehicle. In contrast, estradiol treatment improved object recognition memory and decreased anxiety-like behavior in the circular open field of older but not young rats and decreased depressive-like behavior of young but not older animals. Thus, our findings indicate that age affects the outcome of estradiol therapy in the brain.

The Efficacy of Pure Natural Repellents on Rat Responses Using Circular Open Field

The Efficacy of Pure Natural Repellents on Rat Responses Using Circular Open Field

Hippocampal damage produces retrograde but not anterograde amnesia for a cued location in a spontaneous exploratory task in rats

Performance in several memory tasks is known to be unaffected by hippocampal damage sustained before learning, but is severely disrupted if the same damage occurs after learning. Memories for preferred locations, or home bases, in exploratory tasks can be formed by rats with hippocampal damage, but it is unknown if the memory for a home base survives hippocampal damage. To examine this question, for 30 min each day for five consecutive days, rats explored a circular open field containing one local cue. By Day 5 the rats preferentially went directly to that location, spent the majority of their time at that location, made rapid direct trips to that location when returning from an excursion and so demonstrated that the location was a home base. Memory for the cued location was examined after a 24 h or 14-day interval with the cue removed. In Experiments 1 and 2, control rats and rats with prior N-methyl-D-aspartic acid hippocampal lesions demonstrated memory of the home base location by making direct trips to that location. In Experiment 3, rats that had first explored the open field and cue and then received hippocampal lesions showed no memory for the cued location. The absence of anterograde impairment vs. the presence of retrograde impairment for memory of a spatial home base confirms a role for the hippocampus in the retention of spatial memory acquired during exploration.

Incidental (unreinforced) and reinforced spatial learning in rats with ventral and dorsal lesions of the hippocampus

We investigated whether the ventral and dorsal hippocampus were differentially involved in incidental spatial learning. Rats with ventral and dorsal hippocampal lesions were tested on an unreinforced test of spatial memory that takes advantage of their natural propensity to explore novelty. Rats were presented with two copies of an identical object in a large circular open field arena. Subsequently, the rats were placed back into the open field with one of the objects displaced to an adjacent quadrant of the arena. Sham-operated rats and rats with ventral hippocampal lesions spent more time in the quadrant that contained the displaced object than in the quadrant that contained the non-displaced object, and more time investigating the displaced object than the non-displaced object. Rats with dorsal hippocampal lesions were impaired on both measures. Both sham and ventral hippocampal lesioned rats subsequently learned to retrieve a food pellet in the ends of each arm of a radial maze. Rats with lesions to the dorsal hippocampus showed no significant improvement in the number of errors made across training sessions and made significantly more errors, overall, than rats with ventral hippocampal or sham lesions. The findings suggest that an intact dorsal but not ventral hippocampus is necessary for spatial learning in rats.

Patterns of retrograde amnesia for recent and remote incidental spatial learning in rats

A non-navigational test of incidental spatial learning was used to determine whether hippocampal damage causes temporally-graded retrograde amnesia (TGRA) for allocentric-spatial information. Rats were exposed to two identical objects in a circular open field for 7 min on seven consecutive days. In the 1-3 days after the last day of familiarization, rats received neurotoxic lesions of the hippocampal formation (HPC) or sham lesions. Another two groups received the same lesions 3 weeks after familiarization. The rats were then placed back in the open field with one object displaced, and the time spent in each of the quadrants as well as time spent exploring the objects was recorded. Rats that received HPC lesions 3 weeks but not 1-3 days after familiarization showed evidence of preserved remote spatial memory; however, their remote memory was expressed through different behavior than control rats. Rats with HPC lesions spent more time with the displaced object than with the object that remained in the same place, whereas control rats spent more time in the quadrant where the displaced object used to be. These results suggest that remote spatial memories may be preserved with a sufficiently long familiarization-to-surgery interval before HPC lesions, but that the nature of these memories may differ in quantity and/or quality from those of intact rats.

Effects of rat sex differences and lighting on locomotor exploration of a circular open field with free-standing central corners and without peripheral walls

A typical open field consists of a square enclosure, bounded by four straight walls joined by identical corners. For decades behavioral researchers have used the open center and more sheltered perimeter of such fields to examine the effects of drugs, sex differences, and illumination on the behavioral expression of fear and anxiety. The present study “reversed” the relative security of the center and periphery of a circular field to re-examine the functional relation of open field behavior to experience, sex differences and lighting. Across six daily exposures, males in both the light and dark rapidly increased their preference for the center. Females in the light developed a similar pattern, though more slowly; females in the dark continued to spend the great majority of their time in the open periphery, including the edge of the field. The behavior of all groups, but especially the dark females, strongly supports the continued importance of environmental assessment in open field behavior.

CA1 ischemic injury does not affect the ability of Mongolian gerbils to solve response, direction, or place problems

Open field and T-maze paradigms are used to test the effects of hippocampal lesions on spatial memory in rodents. Place cells in the dorsal CA1 region of the hippocampus are known to be responsible for the formation of global place maps, while CA3 neurons respond to changes in local contexts. It is proposed here that when dorsal CA1 is selectively destroyed, gerbils will be unable to solve direction and place problems while context-dependent representations of relative maze positions should be spared since CA3 cells are left intact. Twenty female Mongolian gerbils were subjected to 5 min of forebrain ischemia, and, along with 20 controls, were subsequently tested on a response, direction or one of two types of open field place problems. Locomotion in a circular open field was recorded as a measure of hyperactivity. Gerbils with damage restricted to dorsal CA1 were hyperactive compared to controls, but were not impaired on place, direction, or response tasks. Because gerbils solved these tasks in the absence of dorsal CA1, maze tasks which have traditionally been labeled “place” or “direction” tasks may actually be testing the animal's ability to discriminate between two relative contexts, without the need for a global place map. Our findings support recent reports that different hippocampal subfields control different aspects of spatial learning and memory. Specifically, the context-dependent representations in CA3 appear to support the learning of the “place” and, likely, “direction” solutions in current and previous open field and T-maze tasks.

Analysis of the Trajectory of Drosophila melanogaster in a Circular Open Field Arena

BackgroundObtaining a complete phenotypic characterization of a freely moving organism is a difficult task, yet such a description is desired in many neuroethological studies. Many metrics currently used in the literature to describe locomotor and exploratory behavior are typically based on average quantities or subjectively chosen spatial and temporal thresholds. All of these measures are relatively coarse-grained in the time domain. It is advantageous, however, to employ metrics based on the entire trajectory that an organism takes while exploring its environment.Methodology/Principal FindingsTo characterize the locomotor behavior of Drosophila melanogaster, we used a video tracking system to record the trajectory of a single fly walking in a circular open field arena. The fly was tracked for two hours. Here, we present techniques with which to analyze the motion of the fly in this paradigm, and we discuss the methods of calculation. The measures we introduce are based on spatial and temporal probability distributions and utilize the entire time-series trajectory of the fly, thus emphasizing the dynamic nature of locomotor behavior. Marginal and joint probability distributions of speed, position, segment duration, path curvature, and reorientation angle are examined and related to the observed behavior.Conclusions/SignificanceThe measures discussed in this paper provide a detailed profile of the behavior of a single fly and highlight the interaction of the fly with the environment. Such measures may serve as useful tools in any behavioral study in which the movement of a fly is an important variable and can be incorporated easily into many setups, facilitating high-throughput phenotypic characterization.

Odour–place paired-associate learning and limbic thalamus: Comparison of anterior, lateral and medial thalamic lesions

Several subregions in the limbic thalamus have been suggested as the key locus for diencephalic amnesia, including the anterior thalamic nuclei, intralaminar nuclei and mediodorsal nuclei. There is, however, no consensus as to a single critical site and recent research has suggested instead that different thalamic areas may contribute to diencephalic amnesia in subtly different ways. This study compared the effects of lesions to anterior (AT), lateral (LT) and posteromedial (MT) aggregates of thalamic nuclei on Gilbert and Kesner's [Gilbert, PE, Kesner, RP. Role of the rodent hippocampus in paired-associate learning involving associations between a stimulus and a spatial location. Behav Neurosci 2002;116(1):63–71; Gilbert, PE, Kesner, RP. Localization of function within the dorsal hippocampus: the role of the CA3 subregion in paired-associate learning. Behav Neurosci 2003;117(6):1385–94] paired-associate task, in which rats were postoperatively trained to form an arbitrary association between odours and spatial locations in a circular open field. Both AT and LT lesions, but not MT lesions, severely impaired odour–place paired-associate learning. Probe trials revealed that the rats were not using specific location information after acquisition training. All groups were able to learn non-associative odour and place discrimination tasks quickly, with only the AT group showing delayed acquisition. This study provides the first direct comparison of different thalamic lesions on paired-associate learning and new evidence on the importance of the LT region in learning and memory. The results support the notion that injury to both the AT and LT subregions of the thalamus may each be major contributors to diencephalic amnesia. There is need for traditional models of memory function to take greater account of the contributions of thalamic nuclei.

Anterior perirhinal cortex kindling produces long‐lasting effects on anxiety and object recognition memory

Temporal lobe epilepsy (TLE) is frequently accompanied by memory impairments and, although their bases are unknown, most research has focused on the hippocampus. The present study investigated the importance of another medial temporal lobe structure, the perirhinal cortex (Prh), in changes in memory in TLE using kindling as a model. Rats were kindled twice daily with anterior Prh stimulation until three fully generalized seizures were evoked. Beginning 7 days later and on successive days, rats were tested in an elevated plus maze, a large circular open field, an open field object exploration task and a delayed-match-to-place task in a water maze in order to assess anxiety-related and exploratory behaviour, object recognition memory and spatial cognition. Kindling increased anxiety-related behaviour in both the elevated plus and open field mazes and disrupted spontaneous object recognition but spared all other behaviours tested. These results are consistent with other findings indicating a greater role for the Prh in object memory and emotional behaviour than in spatial memory and contrast with the selective disruption of spatial memory produced by dorsal hippocampal kindling. The site-selectivity of the behavioural disruptions produced by kindling indicates that such effects are probably mediated by changes particular to the site of seizure initiation rather than to changes in the characteristic circuitry activated by limbic seizure generalization. Further investigation of the behavioural effects of Prh kindling may be useful for studying the mechanisms of mnemonic and affective dysfunction associated with TLE and offer insights into bases for variability in such dysfunction across patients.

Effects of nonsaponin fraction of red ginseng on learning deficits in aged rats

Previously we reported that oral application of red ginseng significantly ameliorated learning deficits in aged rats and young rats with hippocampal lesions. In the present study, we investigated the effects of the nonsaponin fraction of red ginseng on learning deficits in aged rats in behavioral studies and those on long-term potentiation (LTP) in the hippocampal CA3 subfield in young rats in electrophysiological studies. In the behavioral studies, three groups of rats [aged rats with and without oral administration of the nonsaponin fraction of red ginseng and young rats] were tested with the three types of spatial-learning task [distance movement task (DMT), random-reward place search task (RRPST), and place-learning task (PLT)] in a circular open field. The results in the DMT and RRPST indicated that motivational and motor activity was not significantly different among the three groups of rats. However, performance of the aged rats without nonsaponin was significantly impaired in the PLT when compared with the young rats. Treatment with nonsaponin significantly ameliorated deficits in place-navigation learning in the aged rats in the PLT. In the electrophysiological studies, effects of nonsaponin on the LTP in the CA3 subfield of the hippocampal slices were investigated in vitro. Pretreatment with nonsaponin significantly augmented the increase in population spike amplitudes in the CA3 subfield after LTP induction. These results suggest that the nonsaponin fraction of red ginseng contains important substances to improve learning and memory in aged rats and that this amelioration by nonsaponin might be attributed partly to augmentation of LTP in the CA3 subfield.

Riluzole restores motor activity in rats with post-traumatic peripheral neuropathy

Riluzole is a presynaptic inhibitor of glutamate release with neuroprotective properties. In order to evaluate the effects of riluzole on motor activity in post-traumatic peripheral neuropathy (PTPN), the sciatic nerve of Wistar male rats was exposed monolaterally and subjected to crushing for one min by a surgical forceps. Animals received an intraperitoneal treatment with riluzole (2, 4 or 8 mg/kg per day), diclofenac (5, 10 or 20 mg/kg) or with vehicle for 3 days. Motor activity and coordination was evaluated in a circular open field and in the rotorod test. The treatment with riluzole stimulated ambulation in PTPN rats and improved their motor performance and coordination. The effect of treatment with riluzole on locomotor activity was greater than that of treatment with diclofenac and was dose-dependent. Furthermore, in contrast to vehicle- and diclofenac-treated rats, animals treated with riluzole showed a long-lasting improvement of locomotor activity as it was assessed 7 days after the end of treatment. These findings suggest that riluzole may improve motor performance in PTPN, and this does not depend on its antinociceptive activity. Its neuroprotective properties are possibly involved in this effect.