Simple Maze Research Articles

Homing behaviour of juvenile Australian raspy crickets (Orthoptera: Gryllacrididae)

Abstract. Juvenile gryllacridid Orthoptera, known as raspy crickets, build nests or burrows as soon as they hatch. Both juveniles and adults are central place foragers that search for food at night and return to the same nest each morning. This study examines the homing abilities of juveniles of an undescribed species of gryllacridid from Western Australia. Juveniles were placed in a simple maze, which consisted of two chambers, one containing the nest and the other empty, linked by wide glass tubes to a central chamber containing food. The food was placed in this chamber with a consistent orientation relative to the exit tubes leading to the nest and empty chambers. Juveniles appeared to learn which chamber contained their nest and thereafter ignored the route towards the empty chamber. By exchanging the connecting glass tubes, it could be established that juvenile crickets were not using chemical trails to find their home. The positions of the empty and nest chambers with respect to the central chamber were exchanged and, in a separate manipulation, the spatial configuration of the food in the central chamber was also changed. Both manipulations resulted in a decrease in successful returns to the nest chamber, the former because the nest had been relocated, the latter presumably because the spatial arrangement of items within the food chamber now presented orientation cues, which led to the empty chamber. Furthermore, juveniles were able to estimate distance travelled, despite the absence of chemical or visual cues. Juvenile raspy crickets appear to be able to maintain nest fidelity from a very early age by using spatial landmarks and appear capable of measuring translational displacement intrinsically.

Experimental evidence for spatial learning in cuttlefish (Sepia officinalis).

Laboratory mazes were used to study spatial-learning capabilities in cuttlefish (Sepia offcinalis), using escape for reinforcement. In preliminary observations, cuttlefish in an artificial pond moved actively around the environment and appeared to learn about features of their environment. In laboratory experiments, cuttlefish exited a simple alley maze more quickly with experience and retained the learned information. Similar improvement was not found in open-field mazes or T mazes, perhaps because of motor problems. Cuttlefish learned to exit a maze that required them to find openings in a vertical wall. The wall maze was modified to an arena, and simultaneous discrimination learning and reversal learning were demonstrated. These experiments indicate that cuttlefish improve performance over serial reversals of a simultaneous, visual-spatial discrimination problem.

Acquisition of dominance status affects maze learning in mice

Learning is likely to be costly and thus subject to trade-off with other components of life history. An obvious prediction, therefore, is that investment in learning, and thus learning performance, will vary with individual life history strategy and the reproductive value of the learning outcome. We tested this idea in the context of social dominance in male laboratory mice, using a simple radial maze paradigm to compare the ability of high- and low-ranking male mice to track changing food location. We tested animals in randomly selected pairs before and after establishing aggressive rank relationships to distinguish intrinsic differences in learning ability from those attributable to acquiring high or low rank. There was no difference in learning between later dominants and subordinates prior to establishing rank relationships. After pairing, however, dominants showed a significantly greater percentage of correct responses, with the difference being greatest earlier in a sequence of trials. The percentage of correct responses also increased with the amount of aggression initiated during pairing. The results thus appeared to reflect a state-dependent change in learning associated with the aggressive social relationships formed during pairing.

Repetitive atrial flutter as a complication of the left-sided simple maze procedure

Background. Of 41 patients who had undergone a left-sided simple maze procedure, 4 (9.8%) developed repetitive tachycardia due to atrial flutter, and required radiofrequency catheter ablation. Linear ablation of the right atrial isthmus was effective to treat atrial flutter. Methods. We conducted an electrophysiologic study of atrial flutter and determined its reentry circuit on the atrium. We consider how to reduce atrial flutter after the left-sided simple maze procedure. Results. Common atrial flutter through the right atrial isthmus was induced in all 4 patients, and linear ablation on the right atrial isthmus was effective in 3 of these. An incisional atrial flutter around the right atriotomy was also induced in 2 of 4 patients; both were successfully treated by linear ablation between the right atriotomy and the inferior vena cava. Conclusions. Common atrial flutter through the right atrial isthmus is a risk after the left-sided simple maze procedure. When a left-sided simple maze procedure is performed, sufficient cryoablation on the right atrial isthmus of the arrested heart should be administered to prevent postoperative atrial flutter.

Postnatal outcomes in term and preterm lambs following fetal growth restriction.

1. Epidemiological evidence indicates that low birthweight increases the risk of a number of adult-onset diseases. It is now apparent that many babies with a low birthweight may have been subjected to a combination of reduced growth rates in utero as well as preterm birth. However, the long-term effects of preterm birth following intra-uterine growth restriction (IUGR) are unknown. Thus, our objectives were: (i) to identify prenatal factors associated with preterm birth in IUGR fetuses; and (ii) to characterize postnatal effects of preterm birth following IUGR. 2. We studied pregnant sheep and their offspring, in which fetal growth was restricted by umbilico-placental embolization during late gestation. Some of these animals were born at term (146 +/- 1 days) and some were born prematurely (139 +/- 1 days). In both groups, we have conducted longitudinal studies of postnatal respiratory function, cardiovascular function and learning ability up to 6-8 weeks of age. 3. Before birth, IUGR fetuses born prematurely (P-IUGR) were more hypoxaemic and acidaemic and had higher haemoglobin concentrations than both control fetuses and IUGR fetuses born at term (T-IUGR). In P-IUGR fetuses, plasma cortisol concentrations increased earlier than in the two other groups. The P-IUGR lambs had lower birthweights than T-IUGR lambs and both groups of IUGR lambs remained lighter than controls for 8 weeks. 4. After birth, P-IUGR lambs were hypoxaemic compared with T-IUGR and control lambs. Pulmonary diffusing capacity (adjusted for lung volume) was significantly lower in both groups of IUGR lambs than in controls, with P-IUGR lambs having lower values than T-IUGR lambs. Lung compliance (adjusted for lung volume), was not different between P-IUGR and control lambs, but values were higher in T-IUGR lambs than in control and P-IUGR lambs. Chest wall compliance (adjusted for lung volume) was higher in both groups of IUGR lambs than in controls. 5. During the 8 week postnatal study period, both groups of IUGR lambs had lower mean arterial pressures than control lambs; this relative hypotension was greatest in P-IUGR lambs. 6. In tests of learning ability, P-IUGR lambs took longer to complete a simple maze task at all ages and, in the second postnatal week, made a greater number of errors compared with controls. In an obstacle course, P-IUGR lambs recorded longer trial durations; they also made more errors than control lambs. 7. We conclude that preterm birth in the presence of late- gestational placental insufficiency and IUGR can result in specific effects on respiratory and cardiovascular development after birth, in addition to the effects of IUGR alone.

Assessment of learning ability and behaviour in low birthweight lambs following intrauterine growth restriction.

The present study used behavioural tasks to assess learning ability and behaviour in postnatal lambs, and to examine the effects of low birthweight (LBW) and age on subsequent performance. It was hypothesized that intrauterine growth restriction (IUGR) and LBW lead to learning and behavioural deficits in the early postnatal period. IUGR and LBW were induced by umbilico-placental embolization from 120 days of gestational age (g.a.) to the onset of labour. Behavioural studies were performed on 6 LBW and 6 control lambs between 2 and 6 weeks after birth. LBW lambs were born at 139+/-1 days g.a. (2.4+/-0.2 kg) and control lambs were born at 149+/-1 days g.a. (4.5+/-0.4 kg). Three tasks were used to assess the learning ability and behaviour of the lambs: a simple maze, an obstacle course, and a T-maze. LBW lambs took longer to complete the simple maze at all ages, and made a greater number of errors at Week 1 of testing compared to control lambs; the total trial duration and number of errors decreased with age for both groups. In the obstacle course, the times taken to complete the first and third trials were used for analysis; a decrease in trial time and the number of errors from Trial 1 to Trial 3 were indications of the lamb's ability to learn how to negotiate the objects within the course. LBW lambs recorded longer trial durations for the first trial at Week 5 of testing, and for the third trial at Week 4. LBW lambs made more errors for the first trial at Week 5 of testing than control lambs. In the T-maze, there was no significant effect of treatment or age. It was concluded that differences between the groups may have been the result of LBW lambs being prematurely born. The value of these tasks in the assessment of learning ability and behaviour in young lambs is discussed.

Reference memory, anxiety and estrous cyclicity in C57BL/6NIA mice are affected by age and sex

Age-related changes in learning and memory are common in rodents. However, direct comparisons of the effects of aging on learning and memory in both males and females are lacking. The present study examined whether memory deteriorates with increasing age in C57BL/6NIA mice, and whether age-related changes in learning and memory are similar in both sexes. Male and female mice (five, 17 and 25 months of age) were tested in a battery of behavioral tasks including the Morris water maze (spatial and non-spatial reference memory), simple odor discrimination (olfactory reference memory), plus maze (anxiety/exploration), locomotor activity, and basic reflexes. Five-month-old mice learned the water maze and odor discrimination tasks rapidly. Relative to five-month-old mice, 25-month-old mice exhibited impaired spatial and olfactory reference memory, but intact non-spatial reference memory. The spatial reference memory of 17-month-old mice was also impaired, but less so than 25-month mice. Seventeen-month-old mice exhibited intact non-spatial (visual and olfactory) reference memory. Five and 25-month-old mice had similar levels of plus maze exploration and locomotor activity, whereas 17-month-old mice were more active than both groups and were slightly less exploratory than five-month-old mice. Although sex differences were not observed in the five- and 25-month groups, 17-month-old females exhibited more impaired spatial reference memory and increased anxiety relative to 17-month-old males. Estrous cycling in females deteriorated significantly with increased age; all 25-month-old females had ceased cycling and 80% of 17-month-old females displayed either irregular or absent estrous cycling. This study is the first to directly compare age-related mnemonic decline in male and female mice. The results suggest that: (i) aged mice exhibit significant deficits in spatial and olfactory reference memory relative to young mice, whereas middle-aged mice exhibit only a moderate spatial memory deficit and; (ii) spatial reference memory decline begins at an earlier age in females than in males, a finding that may be related to the cessation of estrous cycling.

Walking through a maze alters the architecture of sleep.

Human and animal studies imply that sleep is a critical period for consolidation of recent memories. Whereas the majority of researchers focussed on the procedural learning, the present human study concerns how storing of spatial information and episodic memory are linked to sleep stages. Two city mazes, a simple and a complex one, were created by means of a computer program. Local aspects of these mazes appeared as street scenes on a TV-screen. Our subjects sat in front of the screen and manoeuvered through the maze by the help of a three-button PC mouse. Thus, each subject took a 'mental walk' through an imaginary city. The task was to find various end-points and to find the way back to the starting point. Subjects of two experimental groups 'walked' through either the simple or complex city maze for eight hours. Afterwards the subjects slept in our laboratory, where their sleep stages could be measured polygraphically. Subjects who had explored the simple maze showed considerable alteration in sleep architecture. They remained significantly longer in sleep Stage 2 than subjects who had explored the complex maze. Moreover, with successful orientation in the simple maze sleep stages occurred aperiodically, whereas walking through the complex maze was associated with sleep stages in accordance with ultradian cycles, as observed in a control group. Compared to subjects of the control group who had experienced neither maze, the subjects of both experimental groups had significantly enhanced EEG sleep spindle activities. Alteration in temporal architecture of sleep and selective prolongation of sleep Stage 2 following spatial orientation point to a functional linkage between cognitive mapping of space and sleep Stage 2 with enhanced EEG spindle activity.

Cognitive Dysfunctions Induced by Scopolamine Are Reduced by Systemic or Intrahippocampal Mineralocorticoid Receptor Blockade

Central cholinergic blockade with scopolamine (SCOP) produces profound cognitive impairments in human and animal subjects. We hypothesized that cognitive deficits induced by cholinergic blockade originate partly from its ability to enhance reactivity to the environment, an effect that would be ameliorated by prior mineralocorticoid receptor (MR) blockade, because MR antagonists reduce reactivity to novelty. In the present study, we investigated whether or not systemic or intrahippocampal infusions of the MR antagonist spironolactone (SPIRO) would affect SCOP-induced cognitive impairments in a water maze task. Adult male Lister hooded rats (350–450 g) served as subjects. In Experiment 1, rats were administered SPIRO (0 or 100 mg/kg IP) followed 10 min later by SCOP (0, 0.5, or 2.0 mg/kg IP; n = 10/group). In Experiment 2, groups of rats implanted with hippocampal cannulae received central infusions of SPIRO (50 ng/μl; 3 μl in total) 10 min prior to SCOP injection (2.0 mg/kg IP; n = 6/group). Behavioural testing started 15 min after SCOP administration and consisted of a simple water maze task in which animals were required to locate a submerged platform using spatial cues. The testing regime consisted of two phases: a) acquisition, and b) retention, 24 h later. Peripheral, but not central, injections of SPIRO enhanced water maze performance during acquisition in SCOP-treated rats, as shown by shorter latencies and shorter distances travelled to locate the hidden platform. Both peripheral and central SPIRO administration reduced the long-term retention deficits in performance in the SCOP-treated animals. These data are in general agreement with a growing body of research suggesting that corticosteroid hormones interact with central cholinergic systems to affect both physiological and behavioural responses. MR blockade may reduce an animal's reactivity to the environment and enable it to selectively filter out extraneous stimuli that it would otherwise react to, thus impairing performance.

Application of a neural network based classifier system to AGV obstacle avoidance

This paper describes the application of a neural network based classifier system to the control of a simulated autonomous guided vehicle (AGV) in a simple obstacle avoidance task. A mechanism for concurrent exploration and exploitation of a maze environment based on Kohonen feature maps is proposed and its implementation in a hybrid learning system is described. Two variations of the underlying connectionist path structure are presented and their performance analyzed in a simple simulated maze environment.

Effects of ovariectomy upon performance of a maze learning paradigm in the adult female rat.

To determine what effect ovariectomy and the accompanying sudden loss of circulating gonadal hormones has on spatial learning performance in the adult rat, two groups of rats were tested on the Lashley III simple alley maze following surgery. Ovariectomized animals were compared with a control group of animals that underwent laparotomy at the same time. The ovariectomized group evidenced superior performance on the maze task, as measured by latency to reach goal (running times) and error scores. It is suggested that this finding provides further evidence for the role of gonadal steroid hormones in the manipulation of functions related to learning and memory, especially in the hippocampus.

Characteristics on Swarm Intelligence Generated in Multi-Robot System. Space Coverage Behavior and its Application.

This paper deals with two fundamental evaluation of characteristics of swarm intelligence in multi-robot system. One is related to swarm intelligence emerged as an ability of space coverage behavior. The other is that as an ability of solving a simple maze. In general, a certain ability emerged only in multi-robot system is called ‘swarm intelligence’ and the multi-robot system is expected to consist of many robots with simple mechanical function and small intelligence. With respect to space coverage behavior generated by many robots equipped with locomotion function and obstacle avoidance intelligence, we investigate the characteristics of space coverage ratio with respect to two parameters; one is population size of multi-robot system and the other is diameter size of a single robot. We show that the effect of population size on the space coverage behavior is greater than the ratio of the population size increase, and that the effect of robot diameter is minor in the case of large population size of multi-robot system. In using the multi-robot system for the task to find the route in simple maze the multi-robot system can solve simple maze problem and we evaluate the ability of accomplishment of the task.

Using self-organising feature maps for the control of artificial organisms

Variations on the standard Kohonen feature map can enable an ordering of the map state space by using only a limited subset of the complete input vector. Also it is possible to employ merely a local adaptation procedure to order the map, rather than having to rely on global variables and objectives. Such variations have been included as part of a hybrid learning system (HLS) which has arisen out of a genetic-based classifier system. In this paper a description of the modified feature map is given, which constitutes the HLSs long term memory, and results on the control of a simple maze running task are presented, thereby demonstrating the value of goal related feedback within the overall network.

Strain differences of mice in learning of swimming behavior and effect of hemicholinium and vasopressin. Observation by a simple water maze apparatus

In order to determine the strain differences in learning of swimming behavior and to study the influence of vasopressin or its derivatives on hemicholinium-3-induced impairment of water maze learning in mice, we designed a new apparatus using water maze which has three panels in small fish breeding water bath (L60 x W30 x H36 cm). In the first swimming, six strains of adult male mice, ICR, ddY, ddN, C3H/He, BALB/C and C57BL were subjected to learn swimming behavior twice a day for 6 d in a straight course. Only ICR, ddN, C57BL and BALB/C strain mice were chosen for the next experiment. In the second swimming, mice (ICR, ddN, C57BL, BALB/C) were swum in the water maze apparatus. Scopolamine-induced impairment of water maze learning was produced only in ICR, BALB/C mice, but not in C57BL and ddN strain, which was recovered by physostigmine. Amnesia was not obtained by intracerebroventricular injection (i.c.v.) of cycloheximide and AlCl3 in mice (ICR). Hemicholinium-induced amnesia was improved by vasopressin and desmopressin. Lysine-vasopressin and oxytocin were without affecting hemicholinium-induced amnesia. Pretreatment with a vasopressin antagonist, ([1-(beta-mercapto-beta,beta-cyclopenta-methylene propionic acid), 2-(o-methyl)tyrosine arginine]-vasopressin) resulted in a reversible effect on the improvement of hemicholinium-induced amnesia by vasopressin. Of four different strain mice, ICR mice were the most preferable to the presently used test. They were also more responsive to hemicholinium and vasopressin than the other strains. These results suggest that the simple water maze apparatus may be useful for a pre-examination of nootropics or a study of learning of swimming behavior in mice.

Is Geomagnetic Sensitivity Real? Replication of the Walker-Bitterman Magnetic Conditioning Experiment in Honey Bees

Although the presence of geomagnetic sensitivity has been suspected for a long time in a variety of marine and terrestrial animals, many responses reported in the literature have been based on extensive statistical analysis of orientation results or rely on obscure behavioral activities (like cetacean strandings or honey bee waggle dances.) None of these reports have yet approached the level of clarity and simplicity displayed in experiments with the magnetotactic bacteria, which is the best example of geomagnetic sensitivity in any living organism. Furthermore, claims of magnetic effects on living organisms pervade the literature of biomagnetism, but many have failed subsequent attempts at replication. We need to develop simple and easily replicated experiments for marine and terrestrial animals which can be modified to answer basic questions concerning the psychophysics of any geomagnetic sensory system which might be present. In this paper, we report the first replication of the Walker-Bitterman magnetic anomaly conditioning experiment in honey bees, as well as one of our attempts to slightly alter their basic protocol. We also report our attempts to condition honey bees to magnetic direction in simple maze experiments, and the initial results of a pulse-remagnetization experiment designed to test the ferromagnetic transduction hypothesis. We conclude honey bees are sensitive to the geomagnetic field, that the signal processing for it is more complex than previously thought, and that a ferromagnetic transducer is compatible with all known behavioral data.

Undernutrition during suckling and latent learning ability of rehabilitated adult male rats

The present report investigates the effects of early undernutrition on the latent learning ability of rehabilitated adult male rats in a simple maze task. Rats were undernourished during suckling by feeding their dams an 8% casein diet. Well-nourished dams received a 25% casein diet during the same period. Rats were weaned at 21 days of age and nutritionally rehabilitated until they became adults, when behavioral task was conducted. Under a nonappetitive condition, rats were exposed either to an open field or to a maze apparatus. They were thereafter deprived of water and tested in the maze apparatus. Both well-nourished and undernourished rats that had been previously exposed to the maze performed better than those exposed to the open field. Nutritional treatment had no effect on performance of either the latent learning or of the open-field groups. These results suggest that rehabilitated adult rats are able to learn about the environment when no immediate reinforcement is involved. The discrepancy between our findings and results reported by others may be due to differences in task complexity and/or perhaps to the fact that nutritional rehabilitation also plays a role in reversing some of the deleterious effects of early undernutrition on learning ability of rats.

Evidence that serotonin mediates non-cholinergic neocortical low voltage fast activity, non-cholinergic hippocampal rhythmical slow activity and contributes to intelligent behavior

Previous research has shown that low voltage fast activity (LVFA) in the neocortex and rhythmical slow activity (RSA) in the hippocampus can result from activity in either of two ascending pathways. Activity in neurons in the basal forebrain may produce atropine-sensitive (presumably cholinergic) LVFA and RSA during both Type 1 behavior (e.g., head movement, walking) and Type 2 behavior (e.g., waking immobility, face-washing, tremor). Activity in an aminergic pathway may produce atropine-resistant LVFA and RSA during Type 1 behavior only. The role of 5-hydroxytryptamine (5-HT) in this pathway was studied in rats treated with p-chlorophenylalanine (PCPA;500mg/kg/day × 3, i.p.). Amine levels were measured by high pressure liquid chromatography with electrochemical detection. Brain slow wave and multi-unit activity was assessed by inspection and by a procedure of filtering and integration. PCPA treatment alone had little effect on LVFA or RSA, but following PCPA and atropine (50 mg/kg) together, both LVFA and RSA were attenuated or eliminated. Thus, atropine-resistant LVFA and RSA may be dependent on 5-HT transmission. A combination of PCPA and atropine produced a very severe deficit in performance in a simple water maze. Rats treated with this drug combination may provide an animal model of human global dementia.

History of the BALB/c family.

The BALB/c sublines discussed in this book all originated from a stock of albino mice maintained by Halsey Bagg at Memorial Hospital in New York City. The origin of this stock is obscure. Bagg first acquired these mice from an Ohio dealer around 1913 (Strong 1936) and used them first in his master’s thesis project at Columbia University carried out under the direction of Dr. J. McKeen Cattell. Halsey Bagg studied the abilities of mice and rats to learn a rather simple maze problem, he concluded that mice were much more active than rats and very suitable for behavioral studies. He used two stocks of mice, a yellow strain and the white strain — the latter were destined to be known as Bagg Albinos. Bagg found marked differences in the learning ability of the two kinds of mice to solve the maze problem. By 1916 Halsey Bagg had made filial matings of the albinos for 7 generations. He continued the work at New York University and maintained the albino mouse colony. Halsey Bagg must also have claimed that they were inbred, but after acquiring these mice in 1920 Leonell Strong found some kind of evidence to the contrary (Strong 1978). About this time many of the mouse geneticists in the U.S. were intent upon inbreeding mice. Mice were rapidly emerging as the premier species in experimental cancer research.

Early rearing conditions and within-group behavioral variability

Rats were maintained in enriched or isolated conditions for periods ranging from 10 to 51 days postweaning in four experiments. Animals were subsequently run in a simple maze in acquisition and extinction trials. A measure of variability, the coefficient of variation, showed a tendency for enriched groups to be more homogeneous in their performance, especially after 30 days differential rearing, a finding analogous to some of those in the differential rearing-brain changes literature. Some additional material suggests that these findings may have some generality.

Learning impairment in the radial-arm maze following prolonged cannabis treatment in rats.

Chronic oral administration of cannabis extract to rats (daily delta 9-tetrahydrocannabinol dose 20 mg/kg) was examined in three experiments for its residual effect on radial-arm maze learning following a 1-month drug-free period. Learning a simple eight-arm maze was significantly impaired in rats treated for either 6 months (Experiment I) or 3 months (Experiment II) with the drug. In Experiment III, animals that received the extract for 3 months exhibited significant learning deficits on a much more difficult 12-arm radial maze. The results demonstrate that the deleterious effects of cannabis on radial-arm maze learning are probably due to a tendency toward increased vigilance and perseveration, possibly combined with an impaired utilization of spatial cues.