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At least 19 recordsLinked to original sources

PubMed1988

Maze performance: a direct comparison of food vs. water mazes.

The purpose of these experiments was to evaluate the utility of a water maze for testing performance in nonfood-restricted rats. Water maze performance was compared to performance in a food-rewarded (food) maze. Separate groups of rats were given single daily trials of 34 days in one of two mazes. The path through each maze was identical; in fact, the same maze was used with the exception that the maze was filled with water during water maze testing and left dry during the food maze testing. In the food maze, a chocolate peanut butter chip was placed at the finish. In the water maze an out-of-the-water platform was placed at the finish. The time to reach the finish was measured for each trial. Both free-feeding and food-restricted rats were tested in each maze. Free-feeding rats learned the food maze with great difficulty, requiring more than 30 trials. Food-restricted rats learned the food maze more quickly than did free-feeding rats. Free-feeding rats learned to solve the water maze more quickly than the food maze. Food-restricted rats also learned the water maze more quickly than the food maze and learned both mazes faster than free-feeding rats. Plasma levels of corticosterone, ACTH and prolactin were measured in all rats immediately following completion of the last maze trial. Plasma corticosterone levels were elevated and plasma prolactin levels were decreased in both food-restricted groups as compared to free-feeding rats, demonstrating that food restriction was chronically stressful.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗

PubMed1992

Mice housed in a cage with a maze learn the maze without explicit training.

Mice were housed in a cage with a maze. A water tap was placed at the entrance of the maze. The exit of the maze connected with another cage (home cage). Food was placed in the home cage. Three different multiple mazes (types 1-3) were placed. 1) Mice were housed for 10 h a day in the apparatus and then removed to a normal cage for fasting. One trial per day was carried out after fasting for 13 h. In each trial, a mouse was put at the entrance of the maze and then the number of errors and the time till it reached the home cage was counted. Mice reached a learning criterion at Trial 2. 2) Administering scopolamine (0.125-0.5 mg/kg) 30 min before Trial four disturbed the maze work dose dependently in a type 3 maze, the most complex maze among the three, but did not in type 1 and 2 mazes. 3) Administering scopolamine (0.25-1.0 mg/kg) 30 min before Trial 11 to the mouse of the type 3 maze did not disturb the maze work. These results show that a mouse housed in a cage with a maze learns the maze without explicit training and scopolamine can differentially effect performance based upon the degree of training.

Animals↗

PubMed1996

The influence of open arm ledges and maze experience in the elevated plus-maze.

In Experiment 1, rats were tested in a plus-maze, with or without small ledges on the open arms, after injection with vehicle or chlordiazepoxide (7.5 mg/kg). They were scored either on their first or second exposure to the maze; those scored on trail 2 had received a 5-min undrugged exposure to the maze 24 h earlier. This dose of chlordiazepoxide had a significant anxiolytic effect on trial 1 only in the maze without ledges, and on trial 2 only in the maze with ledges; thus, the presence of ledges differentially affected anxiolytic sensitivity on trials 1 and 2. The results of a factor analysis study (Experiment 2) confirmed that ledges had a differential effect when rats were repeatedly exposed to the maze. Thus, in the maze without ledges, the scores reflecting anxiolytic activity on trial 1 loaded on one factor, whereas the scores from trials 2 and 3 loaded on another independent factor. In the maze with ledges, the scores reflecting anxiolytic activity on trials 1, 2, and 3 loaded on three independent factors. Considering the published evidence and the results of the present study, we suggest that both types of plus-maze may be measuring the same type of anxiety with different sensitivities on trial 1 (e.g., generalised anxiety or fear of open spaces); different types of anxiety on trial 2 (without ledges--phobia/fear of heights; with ledges--not known), and trial 3 in the maze with ledges, yet another type of anxiety. The factor analysis results are also presented for ethological measures on the plus-maze, and for activity and exploration in the holeboard. Based on the factor loadings, a composite measure of anxiety on trial 1 is presented which will increase the sensitivity of the plus-maze to anxiolytic treatments. The measures of motor activity in the plus-maze load on a different factor from those derived from the holeboard, thus cautioning against considering all measures of motor activity as interchangeable.

Animals↗

PubMed2001

Effects of central noradrenaline depletion by the selective neurotoxin DSP-4 on the behaviour of the isolated rat in the elevated plus maze and water maze.

RATIONALE: Social isolation of the rat from weaning influences behaviour following central noradrenaline (NA) depletion by the selective neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4). OBJECTIVES: The study characterised the effects of DSP-4 on the behaviour of isolates in the elevated plus maze and water maze. METHODS: Male Lister hooded rats were reared singly or in groups after weaning. Two weeks postweaning, the rats were injected with DSP-4 (25 mg/kg, i.p.) or saline. From week 4, rats were tested in the plus maze and in the water maze. RESULTS: DSP-4 significantly reduced cortical and hippocampal NA but had no effect on hypothalamic NA. Isolation rearing alone had no significant effects on behaviour in the elevated plus maze but enhanced retention of platform placement in the water maze as measured by increased entries to the platform annulus during the probe test. DSP-4 in group-reared rats increased activity in the open arms and increased general activity in the elevated plus maze with no effect on water maze performance. DSP-4-treated isolates spent less time in the open arms and were hypoactive in the plus maze compared to group-reared DSP-4-treated rats, and had impaired retention of spatial memory in the water maze compared to isolate controls. CONCLUSIONS: DSP-4 treatment had an 'anxiolytic' effect in group-reared rats in the elevated plus maze. In the water maze, isolation rearing enhanced retention of spatial information, an effect normalised by NA depletion. The results demonstrate the importance of noradrenergic function in the regulation of responsiveness to environmental cues.

Animals↗

PubMed2005

Analysis of behavioral asymmetries in the elevated plus-maze and in the T-maze.

When studying functional asymmetries in normal laboratory rats, several behavioral tests have been applied and proven their utility, including turning in rotometers or open-fields, handedness in paw usage, T-maze alternation, and others. Here, we analyzed male Wistar rats in two tests, namely the elevated plus-maze and the T-maze. In these tests, behavioral asymmetries are rather likely to occur, since the animals have to show several types of turns towards the left or right when ambulating through these environments. In a first study using the plus-maze, we provide detailed data on (A) the types of turns which the animals showed when changing their direction within arms (i.e., 180 degrees turns), and (B) the types of turns when proceeding from one arm to an adjacent one (i.e., 90 degrees turns). With respect to asymmetry, we found moderate biases in favor of the right. On the 1st day of plus-maze testing, there was a trend for more rightward turns within arms. On the 2nd day of testing, there was a trend for turns towards the right when alternating between arms of the plus-maze. In a 2nd study, we asked for asymmetries in the plus-maze in animals, which had been treated acutely with the psychostimulatory amphetamine analogue 3,4-methylene-dioxymethamphetamine (MDMA). Psychostimulants drugs, especially amphetamine, have repeatedly been used before in work on functional asymmetry, since they can enhance or reveal asymmetries in normal rats. MDMA had dose-dependent effects on activity, which affected turns within arms, and turns between arms; however, there was only sparse evidence with respect to asymmetry. Interestingly, and if at all, asymmetry was in favor of the right. Finally, we present data for behavior in the T-maze, where we used a spontaneous test version, that is, the animals could explore the maze but had no task to solve. Asymmetries were measured as turns within the start arm (180 degrees), and as left- or rightward turns between arms (90 degrees ) at the T-point of the maze. In both measures, we again obtained evidence for asymmetries in favor of the right. This work supports previous studies showing that the T-maze is suitable to analyze behavioral asymmetries in rats. In addition, it provides new evidence with respect to the elevated plus-maze, indicating that this standard tool of anxiety research may also be useful in research on behavioral asymmetries and their underlying brain mechanisms. Behavioral biases in favor of the right, as shown here, have often been reported before, especially with Wistar rats. Such biases should be taken into account, since they can serve as an approach to study brain/behavior relationships, and since they may affect the outcome of physiological manipulations or behavioral trainings.

Analysis of Variance↗

PubMedDate not supplied

Maze learning in rats: a comparison of performance in two water mazes in progeny prenatally exposed to different doses of phenytoin.

Pregnant Sprague-Dawley CD rats were administered phenytoin by gavage on days 7-18 of gestation in doses of 0, 100, 150 and 200 mg/kg. At 46-53 days of age rat offspring in each litter were divided with half tested in a Biel water maze and half in a new, more complex water maze. On the first test day all rats were tested in a straight channel. On subsequent days rats received 5 trials in the Biel maze or 6 trials in the new maze in path A, followed by 6 trials in path B (in which the start and goal positions were reversed). Analyses showed that phenytoin increased offspring mortality shortly after birth at the highest dose, but did not affect growth at any dose. Phenytoin had no effects on straight channel swimming performance. Analyses of maze performance showed that both mazes differentiated phenytoin offspring from controls, but that the new, more complex maze distinguished the groups more definitively. Maze errors also showed a clear dose-response relationship in the new maze, while no such distinctions were seen in the Biel maze. It was concluded that the new maze design may offer significant gains over the Biel maze in terms of detection sensitivity to prenatally induced CNS injury.

Animals↗

PubMed1995

[Three simple maze tests employing mice housed in maze apparatuses].

This report deals with three different maze methods using spontaneous learning behavior. Forty-eight mice housed in an apparatus with a multiple maze mastered the maze task on the 5th day after the start of housing. Then they were divided into four groups, and two of the groups were treated with AF64A (3.5 nmol, i.c.v.) or trimethyltin (TMT, 3 mg/kg, p.o.), and the other two groups were treated with the vehicle as the respective control. Seven days after the treatment, their memory retrieval was tested. Subsequently, the same mice were housed in the apparatus with a T-maze. After the finish of the experiment using the T-maze, they were housed in the apparatus with an eight arm radial maze. The control groups mastered the T-maze task with a 3-sec delay on the 4th day after the start of housing and the radial maze task on the 10th day after the start of housing. Both the treatments lowered the performance in all maze tasks. These results show that the mice housed in the apparatus with maze learned to negotiate the maze spontaneously, and the apparatuses are useful for estimating memory in mice with little effort.

Animals↗

PubMed2005

Prenatal stress produces more behavioral alterations than maternal separation in the elevated plus-maze and in the elevated T-maze.

Prenatal stress and maternal separation are used in a large number of studies on early adversity consequences and present some similarities in their effects. The present work investigates the behavioral effects of these two procedures on two models of anxiety: the elevated plus-maze and the elevated T-maze. During pregnancy, female rats were submitted to uncontrollable electric foot shock sessions every other day or kept undisturbed. After delivery, litters from undisturbed dams were submitted to either 180-min daily periods of maternal separations from the 3-14th postnatal days or maintained with the dams all the time. Litters from the stressed dams were left undisturbed from the 3-14th postnatal days. Only males were tested. In adulthood, rats were tested in the elevated T-maze or in the elevated plus-maze. In the latter procedure half the subjects were submitted to a 60-min period of restraint immediately before being tested. The following measures were taken in the elevated plus-maze: frequency and time spent in entries into the arms, stretching, rearing, grooming and head dipping. In the T-maze measures of avoidance and escape latencies were used. Our data indicated that prenatal stress had more pronounced anxiogenic effects than maternal separation, as judged by reduced exploration of the open arms of the elevated plus-maze, but mainly after the restraint stress, and increase in avoidance latencies in the elevated T-maze. The other measures not directly involved in the elevated plus-maze arm exploration yielded similar results. Our data indicate that prenatal stress causes more anxiogenic effects in adulthood than maternal separation but, in the elevated plus-maze, these anxiogenic effects are better seen immediately after an acute stress.

Animals↗

PubMed1982

Effects of chlordiazepoxide and imipramine on maze patrolling within two different maze configurations by psychogenetically selected lines of rats.

Male rats of two lines of rats psychogenetically selected and bred for extremes in performance in shuttle box avoidance received an acute IP injection of chlordiazepoxide (CDP; 2.5, 5.0, 10.0 mg/kg), imipramine HCl (IMI: 0.33, 1.0, or 3.0 mg/kg), or vehicle. The rats were placed, 35 min after injection, in an enclosed maze with either a simple configuration with an unilluminated central arena or a complex configuration with a brightly illuminated central arena, and spontaneous maze patrolling was evaluated. Total locomotor activity during the 6-min maze test was significantly reduced by 5--10 mg/kg CDP for both RHA/Verh and RLA/Verh lines of rats in both the simple and the complex maze configurations. Treatment with 10 mg/kg CDP reduced the total explored area for both rat lines in both maze configurations. In addition, the maze area explored by RHA/Verh rats was also reduced by 5.0 mg/kg CDP for the simple configuration and by 2.5 and 5.0 mg/kg CDP for the complex configuration. Entry into the unilluminated central field of the simple maze was reduced by 5--10 mg/kg CDP only in RHA/Verh rats. In contrast, 2.5 mg/kg CDP significantly increased entry into the brightly illuminated central arena of the complex maze for the RLA/Verh rats. The doses of IMI used were without effect on the parameters of maze patrolling behavior evaluated, with the single exception that the locomotor activity of RHA/Verh rats tested in the simple maze configuration was decreased by 3.0 mg/kg IMI. The results indicate that, although the effects of CDP were generally similar for total activity and the area explored in the two psychogenetic lines investigated, there was a qualitative difference in its effect on entry into an illuminated arena.

Animals↗

PubMed1996

Maze procedures: the radial-arm and water maze compared.

Open mazes are primarily designed to measure place learning and memory, using environmental visuospatial cues. However, maze tasks differ along many dimensions, including (1) types of apparatus, which vary from arenas (water maze: WM) to highly structured routes (radial-arm maze: RAM); (2) availability of visuospatial, associative or sensory cues; (3) task requirements which range from spontaneous exploration to complex sequences of choices; and (4) motivation which may involve aversive escape, the opportunity to shelter or to discover novel objects or food at particular locations. Given this diversity, it is likely that mazes tap a variety of processes that contribute to, or affect spatial learning. Hence 'spatial' abilities measured in one procedure may not resemble those engaged in another, posing problems for the interpretation of drug- or lesion-induced deficits. This review compares two types of maze that exemplify key differences in procedure: the RAM and the WM. (1) Visuospatial, associative and sensory factors contributing to place learning in the two mazes are discussed, together with the types of search strategy that they foster, their differing motivation and vulnerability to effects of non-spatial factors, such as stress and training regime. (2) The equivalence of memory processes (acquisition, working and reference memory) assessed in different mazes is considered, and the extent that these may generalize to non-spatial tasks. (3) Differences in application of the two mazes are evaluated. The WM is well-adapted to the study of selective visuospatial factors in place learning and working memory, but less suitable for repeated measures or for assessment of long-term memory deficits. The RAM detects steady-state reference and working-memory deficits, and is suitable for repeated measures, at the expense of precise analysis of the nature of the processes involved.

Animals↗

PubMed2002

Water maze versus radial maze: differential performance of rats in a spatial delayed match-to-position task and response to scopolamine.

Studies rarely assess treatment effects across tasks; the present experiments addressed this issue. In Experiments 1 and 2, rats (n=12) were trained and then tested with variable delays on a spatial match-to-position task sequentially in the water and radial mazes (in counterbalanced order). Experiment 1 compared the effect of 0-, 60- and 1440-min delays on performance in both mazes. Rats required fewer (P<0.05) mean (+/-S.E.M.) sessions to reach criterion performance in the water (11.0+/-1.0) versus radial maze (19.3+/-2.2). In test sessions, performance was impaired delay-dependently when scores were averaged across the two tasks (P<0.05) but no significant effect of task or task x delay interaction was found. In the second experiment, the same rats were retrained and tested with 0-, 1-, 3- and 5-min delays in both mazes and testing followed the administration of scopolamine (0, 0.1, 0.4 and 0.8 mg/kg). The mean (+/-S.E.M.) number of acquisition sessions was similar in the radial (6.33+/-0.34) and water maze (6.08+/-0.46). On the sample portion of trials, performance was impaired at the 0.8 mg/kg dose of scopolamine (P<0.02) in the radial maze only. On the recognition portion of trials in the radial maze, the 0.4 and 0.8 mg/kg doses of scopolamine impaired performance whereas in the water maze task the 0.8 mg/kg dose impaired performance. The pattern of results may reflect different natural tendencies of rats to alternate (win-shift) versus not alternate (win-stay) in dry land versus swim tasks.

Animals↗

PubMed1989

Effects of intrastriatal blockade of glutamatergic transmission on the acquisition of T-maze and radial maze tasks.

Prefrontal cortex and neostriatum constituting the prefrontal system are connected by glutamatergic neurones. The involvement of this corticostriatal projection in control of maze performance of rats was investigated. Glutamatergic transmission mediated by N-methyl-D-aspartate (NMDA) receptors was blocked by intrastriatal injections of dl-2-amino-5-phosphonovaleric acid (AP-5) (50 nmole in 0.5 microliters). In experiment 1, intrastriatal AP-5 was found to increase the number of errors during acquisition of a delayed alternation task in a T-maze. In experiment 2, the effect of intrastriatal AP-5 on acquisition of different 8 arm maze tasks was investigated. AP-5 did not affect the number of reentries on spontaneous and reinforced alternation; pre- and postdelay errors on delayed alternation were not altered. Therefore, intrastriatal NMDA receptor blockade impairs acquisition of a delayed alternation in a T-maze, while intrastriatal blockade of NMDA receptors does not affect acquisition of different 8 arm maze tasks. The impairment in the T-maze task appears not to be due to deficient acquisition of spatial information per se, since 8 arm maze performance is intact. Instead, repeated delays in the T-maze task seem to be the critical component that gives difficulties in acquisition. These difficulties in bridging successive temporal discontiguities were attributed to an increased susceptibility to external and internal interfering stimuli during delays. Thus, striatal NMDA receptors within the prefrontal system may be involved in correct response retention over the duration of delays.

2-Amino-5-phosphonovalerate↗

PubMed1993

Influence of prior maze experience on behaviour and response to diazepam in the elevated plus-maze and light/dark tests of anxiety in mice.

A single prior undrugged exposure to the elevated plus-maze has been reported to reduce open arm activity on retest and to attenuate/abolish the anxiolytic response to benzodiazepines at retest intervals ranging from 48 h to 14 days. The present study was designed to examine the generality of these findings by comparing the effects of prior maze experience on baseline behaviour and response to diazepam in two murine models of anxiety. Parallel experiments were conducted in which DBA/2 mice were exposed/not exposed to the plus-maze, treated daily with saline or diazepam (2-4 mg/kg daily for 8 days) and then tested on either the elevated plus-maze or in the light/dark test of exploration. Results show that, in both tests, diazepam reduced behavioural indices of anxiety in maze-naive mice only. However, interpretation of this apparent loss of diazepam efficacy is at least partially confounded by the observation that maze experience per se altered baseline behaviour in both procedures, reducing open arm activity in the plus-maze and increasing light compartment activity in the light/dark test. The apparent elimination of an anxiolytic response to diazepam in two animal models of anxiety by prior plus-maze experience is discussed in relation to experience-related baseline shifts in behaviour.

Animals↗

PubMedDate not supplied

Branched chain amino acids improve radial-arm maze acquisition and water maze forced-choice learning in rat offspring exposed in utero to hyperphenylalaninemia.

Maternal phenylketonuria results in a high incidence of children born mentally retarded. We showed that the large neutral amino acids valine, isoleucine, and leucine (VIL) ameliorate the effects of intrauterine hyperphenylalaninemia in rats on a test of complex maze learning. To further test the ameliorative effects of VIL on intrauterine CNS development during hyperphenylalaninemia, gravid rats were administered a phenylalanine/p-chlorophenylalanine (index group) supplemented diet with or without VIL added. Controls were given standard diet with or without VIL. All groups were pair-fed to the index group. As adults, the progeny exposed in utero to hyperphenylalaninemia showed characteristic learning impairments in a complex water (Cincinnati) maze on forced and elective-choice phases of the task and deficits in radial-arm maze and Morris maze acquisition, whereas those exposed to hyperphenylalaninemia combined with VIL showed no deficits in the forced-choice phase of Cincinnati maze learning and no evidence of radial-arm maze deficits. However, the improvement was not complete, with no ameliorative effects obtained on the elective-choice phase of the Cincinnati maze or on the Morris hidden platform test. No deficits were seen on phases containing test trials for memory function (Olton and Morris mazes). The acquisition differences occurred in the absence of any effects of VIL on maternal weight gain during gestation, maternal serum amino acid concentrations of phenylalanine or tyrosine, or effects on offspring growth. VIL alone produced no adverse or enhancing effects on learning or memory. Based on these data it was concluded that the VIL supplement continues to show promise as a potential treatment for intrauterinely acquired mental deficiency associated with maternal phenylketonuria.

Amino Acids, Branched-Chain↗

PubMed1999

Effects of ovarian hormones and environment on radial maze and water maze performance of female rats.

The effects of gonadal hormones and environment on performance in an eight-arm radial maze and in the Morris water maze were determined in female rats. Long-Evans female rats were ovariectomized or sham ovariectomized at 35 days of age, and housed in complex environments or in isolation for the duration of the study. One month following surgeries, spatial working memory performance in the radial maze was assessed. Exposure to complex environmental conditions independently enhanced performance, as indicated by increased arm choice accuracy during 20 days of maze training. Additionally, gonadally intact females significantly outperformed ovariectomized females before cyclicity was disrupted by food deprivation. Following radial maze training, spatial reference memory performance was assessed in the same females utilizing the Morris water maze. Gonadally intact females housed in isolation performed significantly more poorly during 16 days of place training trials and displayed significantly shorter times in the platform quadrants and fewer target crossings during probe trials than gonadally intact and ovariectomized females housed in complex environments and ovariectomized rats housed in isolation. Consequently, acquisition and retention of the water maze was impaired by the presence of ovaries, and this impairment was counteracted by exposure to complex environments. Performance did not differ between groups on cued trials, indicating that sensorimotor and motivational functions did not differ between groups. Results of these experiments indicate that endogenous gonadal hormones can differentially affect performance on tasks of spatial working and spatial reference memory, and that environmental conditions can interact with gonadal hormones to affect behavior.

Animals↗

PubMed2002

Prior maze experience required to alter midazolam effects in rats submitted to the elevated plus-maze.

In rodents, prior maze experience increases open arm avoidance (OAA) and compromises the anxiolytic effects of benzodiazepines in a subsequent exposure to the elevated plus-maze (EPM), a phenomenon referred to as "one trial tolerance" (OTT). Nevertheless, a possible correlation between these intriguing events remains unclear. Using maze-naive and maze-experienced (free exploration of the EPM for 5 min) rats, Experiment 1 confirmed the anxiolytic effects of midazolam (MDZ; 0.125-1.0 mg/kg) in maze-naive rats, while both increased OAA and OTT to the MDZ anxiolytic effects were observed in maze-experienced rats. However, our results from Experiment 2, designed to assess whether open, enclosed or both arms experience is involved in increased OAA and OTT, showed that MDZ retained its efficacy in rats confined either to an open or enclosed arm, where no significant changes in open arm exploration were observed when compared to the maze-naive group, therefore suggesting that prior experience in the whole apparatus may be involved in the loss of the anxiolytic MDZ effects. Results are discussed in terms of a possible correlation between increased OAA and the OTT phenomenon elicited in a subsequent exposure to the EPM.

Animals↗

PubMed2002

Residential maze as a task for testing rats' maze learning ability: effects of hippocampal lesions and cholinergic receptor antagonists.

We investigated whether rats can learn mazes by a procedure in which rats were left in the maze (residential maze) in groups for 1 h a day. Water and food locations, which served as the start and goal boxes respectively in the test trial, were at the opposite ends of the maze. On the test trial conducted everyday before the residence period, animals put in the start box showed a significant decrease of the error response into the blind alleys and running time to reach the goal box. Systemic administration of scopolamine (0.25, 0.5 mg/kg), a muscarinic receptor antagonist, dose-dependently increased the number of errors, but mecamylamine, a nicotinic receptor antagonist, had no effect. Bilateral hippocampal lesions retarded both the acquisition and retention of this maze learning. The results suggest that this residential maze procedure is useful for testing maze learning ability in rats.

Animals↗

PubMed1992

Reciprocal overshadowing between intra-maze and extra-maze cues.

In three experiments, rats learned a maze discrimination where the location of food was defined either by reference to extra-maze cues alone, or by both extra- and intra-maze cues. Experiment 1 confirmed earlier results in showing that the presence of intra-maze cues failed to overshadow learning about extra-maze cues, in spite of the former's apparently greater salience. Experiment 2, however, suggested that this result was an artefactual consequence of differences between groups in the proportion of reinforced and unreinforced trials during the course of discriminative training. In Experiment 3, the discrimination was taught by a series of reinforced and unreinforced placement trials, and a significant overshadowing effect was observed. Intra-maze and extra-maze cues seem to compete for association with reinforcement in exactly the same way as any other cues.

Animals↗