Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Spatial Learning”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources
PubMed2004

Age-dependent effects of serotonin-1A receptor gene deletion in spatial learning abilities in mice.

The serotonin (5-hydroxytryptamine, 5-HT) receptor 1A is involved in many physiological functions, including the regulation of learning and memory by acting either as an autoreceptor located on 5-HT neurons (raphe nuclei) or as a heteroreceptor on non-5-HT neurons, mainly in the hippocampal formation. To investigate whether the effects of 5-HT via 5-HT1A receptors on learning are age-sensitive, we evaluated the performance of young-adult (3 months old) and aged (22 months old) 5-HT1A knockout (KO) mice and their homologous wild types (WT) in the hippocampal-dependent spatial reference memory version of the Morris water maze. We demonstrated that young-adult 5-HT1AKO mice exhibit an impairment in learning and retention of the spatial task, as compared to WT mice, without showing any sign of change in their sensori-motor and locomotor abilities or motivation. This genotype effect does not persist during aging. In fact, aged 5-HT1AKO mice seem to be slightly facilitated during the early stages of learning. These results are consistent with a possible prevalence of 5-HT1A raphe functions in learning and memory abilities of young-adult animals, since the effects of the mutation on mice performance (impairment) are opposite to those found after intra-raphe injection of 5-HT1A agonists (facilitation), and with data showing increased activity of 5-HT neurons in 5-HT1AKO mice. The reduced effect of the mutation in aged animals possibly reflects the lower efficacy of autoreceptors due to aging and/or a prevalence of hippocampal heteroreceptors.

Age Factors↗
PubMed1998

Olfactory traces and spatial learning in rats.

We conducted an experiment to assess the use of olfactory traces for spatial orientation in an open environment in rats, Rattus norvegicus. We trained rats to locate a food source at a fixed location from different starting points, in the presence or absence of visual information. A single food source was hidden in an array of 19 petri dishes regularly arranged in an open-field arena. Rats were trained to locate the food source either in white light (with full access to distant visuospatial information) or in darkness (without any visual information). In both cases, the goal was in a fixed location relative to the spatial frame of reference. The results of this experiment revealed that the presence of noncontrolled olfactory traces coherent with the spatial frame of reference enables rats to locate a unique position as accurately in darkness as with full access to visuospatial information. We hypothesize that the olfactory traces complement the use of other orientation mechanisms, such as path integration or the reliance on visuospatial information. This experiment demonstrates that rats can rely on olfactory traces for accurate orientation, and raises questions about the establishment of such traces in the absence of any other orientation mechanism. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1984

Effects of gender and alcoholism on verbal and visual-spatial learning.

Sex differences in cognitive abilities of chronic alcoholics were investigated using a paired-associates learning test with separate but similarly structured verbal and visual-spatial components. Four groups of 35 subjects each, equated for age and education, were tested: male and female alcoholics, and male and female community control subjects. As expected, sex differences were found on the component tasks: overall, nonalcoholic women performed significantly better than nonalcoholic men on the verbal measure, and nonalcoholic men performed better than nonalcoholic women on the visual-spatial measure. Nonalcoholic men had a larger discrepancy between component scores than nonalcoholic women, suggesting greater lateralization of cognitive functions; however, this difference did not reach significance. The effects of alcoholism were different for the sexes. Alcoholic women were not impaired on either the verbal or visual-spatial measure, but the alcoholic men demonstrated deficits in visual-spatial performance. In addition, they showed less difference between verbal and visual-spatial component scores than the other groups, suggesting that alcoholism attenuated the effects of hemispheric specialization for cognitive abilities normally found in men.

Adult↗
PubMed1993

Severity of spatial learning impairment in aging: development of a learning index for performance in the Morris water maze.

The Morris water maze task was originally designed to assess the rat's ability to learn to navigate to a specific location in a relatively large spatial environment. This article describes new measures that provide information about the spatial distribution of the rat's search during both training and probe trial performance. The basic new measure optimizes the use of computer tracking to identify the rat's position with respect to the target location. This proximity measure was found to be highly sensitive to age-related impairment in an assessment of young and aged male Long-Evans rats. Also described is the development of a learning index that provides a continuous, graded measure of the severity of age-related impairment in the task. An index of this type should be useful in correlational analyses with other neurobiological or behavioral measures for the study of individual differences in functional/biological decline in aging.

Aging↗
PubMed2005

Cholinergic parameters and the retrieval of learned and re-learned spatial information: a study using a model of Wernicke-Korsakoff Syndrome.

This is a factorial (2 x 2 x 2) spatial memory and cholinergic parameters study in which the factors are chronic ethanol, thiamine deficiency and naivety in Morris water maze task. Both learning and retention of the spatial version of the water maze were assessed. To assess retrograde retention of spatial information, half of the rats were pre-trained on the maze before the treatment manipulations of pyrithiamine (PT)-induced thiamine deficiency and post-tested after treatment (pre-trained group). The other half of the animals was only trained after treatment to assess anterograde amnesia (post-trained group). Thiamine deficiency, associated to chronic ethanol treatment, had a significant deleterious effect on spatial memory performance of post-trained animals. The biochemical data revealed that chronic ethanol treatment reduced acetylcholinesterase (AChE) activity in the hippocampus while leaving the neocortex unchanged, whereas thiamine deficiency reduced both cortical and hippocampal AChE activity. Regarding basal and stimulated cortical acetylcholine (ACh) release, both chronic ethanol and thiamine deficiency treatments had significant main effects. Significant correlations were found between both cortical and hippocampal AChE activity and behaviour parameters for pre-trained but not for post-trained animals. Also for ACh release, the correlation found was significant only for pre-trained animals. These biochemical parameters were decreased by thiamine deficiency and chronic ethanol treatment, both in pre-trained and post-trained animals. But the correlation with the behavioural parameters was observed only for pre-trained animals, that is, those that were retrained and assessed for retrograde retention.

Acetylcholine↗
PubMed1998

Increased flexibility and selectivity in spatial learning of transgenic mice ectopically expressing the neural cell adhesion molecule L1 in astrocytes.

The expression of the neural cell adhesion molecule L1 is altered by neuronal activity and promotes neurite outgrowth in vitro. To study the effects of L1 on learning and synaptic plasticity, transgenic mice have been created which express L1 ectopically in glial fibrillary acidic protein (GFAP) expressing astrocytes. Ninety mice, including GFAP-L1-transgenic mice from two genetic backgrounds and their littermates, were tested for swimming navigation learning in the Morris water maze according to a standardized protocol. While learning the position of an invisible target platform and also relearning its position after relocation, GFAP-L1-transgenic mice spent a greater fraction of their swim time in the target quadrant. Moreover, they showed a more rapid improvement of escape performance during the first day of training. Factor analysis revealed that this difference in swimming pattern could not be explained by non-cognitive factors. Factor analysis also revealed that, during a probe trial, the GFAP-L1-transgenic mice spent comparatively less time in the old target quadrant than predicted by the increased searching they had shown during acquisition learning. Hence, ectopic expression of L1 by astrocytes in mice appears to be linked to a factor which increases behavioural flexibility and selectivity while learning and relearning, but concomitantly may lead to a relative reduction of spatial retention.

Animals↗
PubMed1996

Basolateral amygdala lesions block glucocorticoid-induced modulation of memory for spatial learning.

This study examined the role of the amygdala in mediating the effects of glucocorticoids on spatial memory in rats. Adrenalectomy (ADX) induced 4-5 days prior to training impaired memory in a water-maze spatial task. This effect was reversed by a posttraining injection of dexamethasone (0.3 mg/kg sc) but not by corticosterone (0.3 mg/kg). Lesions of the basolateral (BLA), but not the central (CEA) or the medial (MEA), amygdala blocked the effects of ADX and dexamethasone. ADX also impaired acquisition. CEA, MEA, and BLA lesions blocked the ADX effect on acquisition. In adrenally intact rats, intracerebroventricular posttraining injections of a specific glucocorticoid receptor (GR or Type-II) antagonist impaired retention, and BLA lesions blocked the effect of the GR antagonist. These findings provide evidence that the BLA is involved in mediating glucocorticoid influences on learning and memory.

Adrenalectomy↗
PubMed1994

Reversible inactivation of the lateral dorsal thalamus disrupts hippocampal place representation and impairs spatial learning.

Place-specific discharge of hippocampal cells was monitored while rats performed daily 15 trials of a spatial memory task. During the intertrial interval between trials 5 and 6, the lateral dorsal nucleus of the thalamus (LDN) was reversibly inactivated. Choice accuracy on the maze became impaired, and many hippocampal place fields became disrupted. These data support the proposition that the LDN passes onto hippocampus important (spatial) information that is used for accurate maze navigation.

Animals↗
PubMedDate not supplied

Place cell rigidity correlates with impaired spatial learning in aged rats.

In humans and in animals, some aged individuals are severely impaired in learning and memory capacity whereas others perform as well as young adults. In the present study, the spatial memory capacity of young and aged rats was characterized by the Morris water maze task, and then firing patterns of hippocampal "place cells" were assessed as the animals explored a familiar environment and a geometrically-altered version of the environment. Spatial representations of hippocampal cells in young and memory-intact aged rats changed upon exposure to the altered environment. In contrast, spatial representations of many cells in aged, memory-impaired rats were unaffected by the environmental alteration. Furthermore, combining all groups, the extent to which spatial representations distinguished the familiar and altered environments predicted learning capacity in the water maze. These findings suggest that a major component of memory impairment in aging may be the failure of the hippocampus to encode subtle differences in contextual information that differ across multiple experiences, such as the sequence of training trials in the water maze.

Aging↗
PubMed1985

Spatial learning disabilities and underachievement among university anatomy students.

In this study the relationship between underachievement in anatomy and spatial ability (both geometrical and anatomical) is investigated. Subjects were second-year medical students at the University of Cape Town from 1980 to 1983. Geometrical spatial ability was measured using a battery of three-dimensional exercises involving the sectioning, joining, translation, rotation and visualization of simple solid objects. Anatomical spatial achievement was measured using university practical examination scores of April, June and October, as well as students' scores on those items in the April, June and November MCQ anatomy examinations which were classified as spatially three-dimensional by a panel of lecturers in anatomy. Non-spatial anatomical achievement was measured using the university essay examination scores of April, June and November, together with students' scores on the non-spatial items in the MCQ anatomy examinations. From 1980 to 1983 it was found that students who failed the battery of geometrical spatial exercises and/or recorded large, persistent deficits on spatial MCQs relative to non-spatial MCQs, scored significantly lower marks in practical anatomy examinations throughout the year than those students who scored well in the battery of geometrical spatial exercises. Spatially competent and spatially inept students performed equally well on the non-spatial MCQs and the non-spatial essay examinations. Borderline and failing students recorded the greatest deficits in anatomical spatial scores (for whom losses of approximately 18% occurred in practical examinations in anatomy). Since potential failures with persistent spatial handicaps can be readily identified by mid-year, a programme of differentiated teaching methods is recommended for these students.

Achievement↗
PubMed1984

Learning spatial dimensions with a visual sensory aid: Molyneux revisited.

The relationship between sensory aid research and several areas of perceptual learning has been explored with five experiments on learning the use of the Binaural Sensory Aid, an electronic sensor in which pitch specifies distance and interaural amplitude difference (IAD) specifies direction. The training task required reaching to objects in near space, with tactile error feedback. Perceptual learning for both dimensions was demonstrated within 72 trials, giving a level of performance comparable to the use of a natural sound source, although performance with the direction cue did not reach asymptote until a second training session. Training was unaffected by various kinds of regularity in the spatial target sequences, or by a reduction in the number of spatial target locations until only two locations were used; at this point directional accuracy declines. Training only one dimension at a time did not produce additional improvement of performance on that dimension, but did impair generalization of the direction cue. Learning of the pitch-distance dimension was generally better than that of the IAD dimension, possibly because of its greater discriminability with this device. Generally, the pattern of results indicates that in learning to use such devices subjects readily determine the sensory dimensions of the codes and have considerable ability to generalize to new locations.

Distance Perception↗
PubMed2000

Effects of batroxobin on spatial learning and memory disorder of rats with temporal ischemia and the expression of HSP32 and HSP70.

The effect of Batroxobin on spatial memory disorder of left temporal ischemic rats and the expression of HSP32 and HSP70 were investigated with Morri's water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats in searching a goal were significantly longer than those of the sham-operated rats and at the same time HSP32 and HSP70 expression of left temporal ischemic region in rats was significantly increased as compared with the sham-operated rats. However, the mean reaction time and distance of the Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of HSP32 and HSP70 immune reactive cells of Batroxobin-treated rats was also less than that of the ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats; and the down-regulation of the expression of HSP32 and HSP70 is probably related to the attenuation of ischemic injury.

Animals↗
PubMed1994

The effect of electroconvulsive shock and nifedipine on spatial learning and memory in rats.

Several traumatic events including brain contusion, electroconvulsive shock therapy, epileptic seizures and others, may cause short-term retrograde amnesia. In spite of much recent attention, pharmacological treatment of memory impairment has not been fully successful. In the present paper we report on the possible antiamnesic action of the L-type calcium channel blocker, nifedipine. Rats trained in the spatial memory task showed gradual improvement in the escape latency to find the submerged platform. After completion of the learning, they also showed a strong spatial bias toward the place that previously contained the target platform. Prolonged post-trial electroconvulsive shock induced memory impairment. The calcium channel blocker, previously reported as a "cognitive enhancer," given either before or after the learning trial revealed no antiamnesic effect. Nifedipine also does not exert any action when given alone. These results suggest that the drug may not have antiamnesic action on human memory disturbed by electroconvulsive therapy.

Animals↗
PubMed2004

Nicotine attenuates spatial learning deficits induced in the rat by perinatal lead exposure.

Maternally lead (Pb)-exposed, juvenile rats exhibit significant deficits in spatial reference memory acquisition and working memory performance in the Morris water maze (MWM). Acute systemic application of nicotine reverses these deficits without affecting behavioral performance of the age-matched, lead-unexposed control animals. These results suggest that nicotinic agonist treatments can ameliorate learning and memory impairments, presumably by compensating for deficient nicotinic function in developmentally lead-exposed animals.

Animals↗
PubMed1997

Learning spatial sequences in unilateral neglect.

Brain-damaged patients with unilateral spatial neglect ignore aspects of the world located on the side opposite their lesion. In the present study we examined the performance of unilateral neglect patients (UN) on an SRT task in which a hybrid repeating sequence (21313) was used. We analyzed the patients' performance for each location separately as a function of the target's location in the trial preceding the response. The UN patients were severely limited in their learning of the sequence when compared to normal controls. In particular, they appeared to learn unique associations (21 and 13) but not ambiguous ones (31 and 32). We discuss two possible explanations for this phenomenon. The first is that UN patients show a deficit similar to that of normal subjects in dual task situations. The second is that the learning deficit is unique to spatial processing impairments of UN patients and is not directly related to research with normal population. We outline future research that may distinguish between these two explanations.

Attention↗
PubMed2002

Differential effects of mGluR1 and mGlur5 antagonism on spatial learning in rats.

The effects of selective mGluR1 and mGluR5 antagonists on long-term acquisition were tested in a spatial three-choice reward-finding test. Bilateral prelimbic injections of the mGluR1 antagonist, (S)-4-carboxyphenylglycine (4-CPG), before training sessions blocked acquisition of correct performance between sessions. Similar injections given after full training of a control group significantly impaired correct performance without causing a complete block. Pretraining injections (intraperitoneal or intravenous) of the systemically active mGluR5 antagonist, 2-methyl-6-(phenylethynyl)pyridine (MPEP), had no effect on long-term acquisition in the reward-finding task. In an open-field test, bilateral prelimbic pretest application of 4-CPG prevented normal adaptation of spontaneous exploration as seen in control animals. MPEP, on the other hand, had no effect. In conclusion, the results confirmed that mGluR1 is involved in spatial long-term acquisition and suggested an additional role in recall of acquired skills. Furthermore, it was concluded that antagonism of mGluR1 or mGluR5 had different effects both in the appetitive spatial task and in the open-field test.

Animals↗
PubMedDate not supplied

[Spatial learning and the hippocampus].

INTRODUCTION: Since publication of the book The hippocampus as a cognitive map by O'Keefe and Nadel in 1978, several theoretical and experimental works have supported the participation of the hippocampus in rodents in spatial processing. Since then, great advances have been made into understanding the potential role of the hippocampus in learning and memory processes, relegating a secondary role to the hypothesis that, in rodents, the hippocampus is restricted to the formation of a cognitive map. DEVELOPMENT: In this work, different forms of spatial navigation are analyzed (taxis, cartographic and route integration-based navigation) on a psychological and neurobiological level. The spatial function of the hippocampus proposed by O'Keefe and Nadel is discussed but a more general model is chosen that explains the function of the hippocampus in mammals, i.e. a model of relational memory. Therefore, in the context of relational memory we attempt to explain the different forms of spatial memory in rodents and present the most relevant experimental data that support a critical role for the hippocampus in this kind of memory. CONCLUSIONS: The studies reviewed in this work support an important role for the hippocampus in spatial processing. However, this does not appear to be its sole function and it possibly operates more widely also participating in relational memory.

Animals↗
PubMed2002

Tiagabine, a gamma-amino-butyric acid transporter inhibitor impairs spatial learning of rats in the Morris water-maze.

gamma-Amino-butyric acid (GABA) is cleaved from the synaptic cleft by uptake via specific transporters. Inhibition of such transporters increases the effectiveness of physiologically released GABA. Increased GABAergic neurotransmission has an impact on learning and memory. Therefore, effects of tiagabine, a GABA-transporter inhibitor, were investigated on spatial orientation in the Morris water-maze. Rats were given four training trials per day for 4 days and a probe trial without platform on the 5th day. Compared to saline treated rats, rats treated daily with 20 mg/kg tiagabine showed impaired learning during the acquisition trials. Retrieval was impaired in rats treated only at the probe trial with tiagabine. These results further elucidate the role of GABA in learning and memory.

Animals↗