Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Spatial Behavior”

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 91 records · Page 5Linked to original sources

Hippocampal morphology and spatially related behavior in Long-Evans and CFY rats.

Behavioral responses to novelty in an open field and spatial learning in a radial maze with four arms out of eight reinforced were tested in male and female CFY and Long-Evans rats. Subsequently, the sizes of the total hippocampi and of various hippocampal cell layers and terminal fields at the midseptotemporal level were measured in Timm-stained sections. No strain differences were found in the open field (except for defecation). In the radial maze, Long-Evans rats showed better spatial reference memory capabilities than rats of the CFY strain. The relative sizes of the intra- and infrapyramidal mossy fiber (IIP-MF) projections did not differ between the strains. Within the more variable CFY strain, a positive correlation between the size of the IIP-MF projection and radial maze performance was found. The absolute sizes of the entire hippocampi and all hippocampal layers at the midseptotemporal level were larger in the CFY strain. The size of the suprapyramidal mossy fiber projection was related to the number of granule cells and to the ratio between granule and CA3 pyramidal cells. In contrast, the size of the IIP-MF projection did not correlate with either of these variables. The results indicate that the size of the mossy fiber projection may be determined mainly by the available postsynaptic surface on the dendrites of CA3 pyramidal neurons. Furthermore, an increased number of granule cells and their larger projection to the apical dendrites of pyramidal neurons does not appear to result in physiological changes with behavioral consequences.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Organization of retrosplenial cortical projections to the anterior cingulate, motor, and prefrontal cortices in the rat.

The retrosplenial cortex (areas 29a-29d) has been implicated in spatial memory, which is essential for performing spatial behavior. Despite this link with behavior, neural connections between areas 29a-29d and frontal association and motor cortices--areas also essential for spatial behavior--have been analyzed only to a limited extent. Here, we report an analysis of the anatomical organization of projections from areas 29a-29d to area 24 and motor and prefrontal cortices in the rat, using the axonal transport of biotinylated dextran amine (BDA) and cholera toxin B subunit (CTb). Area 29a projects to rostral area 24a, whereas area 29b projects to caudodorsal area 24a and ventral area 24b. Caudal area 29c projects to mid-rostrocaudal area 24b, whereas rostral area 29c projects to caudal areas 24a and 24b and caudal parts of primary and secondary motor areas. Caudal area 29d projects to mid-rostrocaudal areas 24a and 24b, whereas rostral area 29d projects to the caudalmost parts of areas 24a and 24b and the secondary motor area and to the mid-rostrocaudal part of the primary motor area. Area 29d also projects weakly to the prefrontal cortex. These differential corticocortical projections may constitute important pathways that transmit spatial information to particular frontal cortical regions, enabling an animal to accomplish spatial behavior.

Animals↗

Active motion, communicative aggregations, and the spatial closure of Umwelt.

On the basis of a simple model of movable organisms that are supplied by semiotic force of attraction or repulsion, several general features of spatial behavior are demonstrated: (1) the stochastic spatial distribution of actively moving organisms is unstable; (2) simple or complex aggregations of organisms appear as a result of active motion; and (3) the ability for active motion ties the organisms with place. These results show that models that apply an internalist approach can considerably simplify the theory of spatial behavior of organic systems. Explanations based on the effects of Darwinian fitness may not be necessary for understanding the origin of biological aggregations.

Animals↗

The effects of type I and type II corticosteroid receptor agonists on exploratory behavior and spatial memory in the Y-maze.

We investigated the effects of two adrenal steroid agonists on adrenalectomized (ADX) rats' performance on the Y-maze. The Y-maze was chosen because memory can be assessed quickly and because it is sensitive to various parameters of exploratory behavior and spatial memory performance. Four days after surgery, ADX rats were injected with aldosterone (ALDO, a selective Type I receptor agonist), RU362 (a selective Type II receptor agonist) or sesame vehicle at three different time points (120 min prior to Trial 1, immediately after Trial 1 or 120 min after Trial 1). SHAM-operated rats injected with vehicle were also tested. The results indicate that vehicle-treated ADX rats were impaired on spatial recognition memory compared to SHAM rats. Treatment with ALDO restored spatial recognition memory performance of ADX rats to a level comparable to SHAM-treated rats by acting on acquisition and consolidation, whereas treatment with RU362 did not change the poor spatial recognition memory performance of ADX rats. Discrimination memory was improved only when either agonist was injected prior to the first trial, strongly suggesting a non-selective effect of corticosteroids on discrimination memory such as increasing arousal. A detailed analysis of exploratory behavior showed that both the ALDO- and RU362-treated rats explored the Y-maze more than the ADX and SHAM groups at all periods of the experiment. These results show that the non-specific increase in exploratory behavior induced by replacing corticosteroids targeted at Type I and Type II receptors was used differentially with the ALDO-treated rats learning and consolidating spatial information better than the RU362-treated rats. These data are discussed along with other evidence to suggest that Type II receptors may require the simultaneous occupancy of Type I receptors to affect learning and memory processes.

Adrenalectomy↗

Spatial and behavioral correlates of hippocampal neuronal activity.

The firing rate of hippocampal neurons in rats was related both to spatial location and to multiple behavioral variables as rats performed 2 kinds of tasks that rely on hippocampal function: a spatial navigation task similar in performance demands to the radial-arm maze task and a simultaneous cue odor-discrimination task. In the place task, most cells had distinct single or multiple place fields, that is, neurons increased firing when the rat was in a particular location or locations. However, in most of these cells, firing rate also varied systematically in relation to behavioral variables, including the speed, direction, and turning angle of the rat as it moved through the place field. In addition, the activity of most cells was time-locked to task-relevant approach movements. In the odor task, most cells fired as the rat sampled discriminative cues or when it executed specific, task-relevant approach movements. Some cells fired selectively in relation to which odors were presented, the configuration of odor cues, the locus of the response, or a combination of these variables. Many cells with spatial correlates in the place task also had striking behavioral correlates when rats performed the odor task in the same environment, and the locus of the increased firing associated with behavior in the odor task was not the same as the place field in the place task. Thus, while the complex stimuli that compose spatial cues are reflected in hippocampal neuronal activity, hippocampal processing is not limited to the representation of spatial location. Rather, the domain of hippocampal representation includes both spatial and nonspatial relations among multiple cues and the actions directed in relation to these cues, across cue modalities, and across behavioral paradigms.

Animals↗

Assessment of working memory in rats using spatial alternation behavior with variable retention intervals: effects of fixed-ratio size and scopolamine.

The effects of fixed-ratio (FR) size, scopolamine, and the interactions between FR size and scopolamine were investigated in male F344 rats on working memory as assessed by spatial alternation behavior maintained under FR schedules of food presentation where the interval between trials was varied among values of 2, 4, 8, 16, and 32 s within each session. The magnitude of the FR size on the correct and incorrect levers was varied systematically from 1 response to 2, 4, 8, or 16 responses in order to determine whether the FR size influenced either the percentage of correct responding, rates of responding, or both. Under the primary baseline condition, that is when the FR size on both the correct and incorrect levers was one response (designated FR1 FR1), the percentage of correct responses decreased with increasing retention interval duration. Increasing the FR size on the correct lever produced FR-dependent increases in the percentage of correct responding as well as in rates of responding. Increasing the FR size on the incorrect lever produced FR-dependent decreases in correct responding, but had little effect on rates of responding. Dose-effect curves for scopolamine were determined on performance maintained under FR values on the correct and incorrect levers, respectively, of FR1 FR1, FR1 FR10, FR10 FR1, and FR10 FR10. In general, scopolamine produced dose-related decreases in the percentage of correct responding, although the magnitude of the effects of scopolamine varied not only with dose, but also with the length of the retention interval and with changes in FR size.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Do migratory or demographic disruptions rule the population impact of pollution in spatial networks?

Ecotoxicology supplies environmental quality criteria mainly based on the potential effects of contaminants on demographic rates of natural populations. Possible impacts through pollutant-induced disruptions of spatial behaviors are totally neglected. Should it be significant to take into account this "second way"? We developed the example of a hypothetical brown trout population living in a river network. We analyzed how behaviors of toxic avoidance or attraction during the spawning migration alter the impact of pollution. Attraction behaviors basically enhanced the bad effect of pollution. More interesting, avoidance behaviors can weakly lift the asymptotic population growth rate, while if there is density-dependent effects on recruitment, pollutant avoidance can actually lead to a substantial drop in equilibrium size. Our model allowed comparing the relative significance of migratory and demographic disruptions for explaining the population impacts of pollution; we thus stress on the need of increasing efforts to develop knowledge relative to toxicant-induced spatial behaviors and to integrate such effects in the definition of environmental quality criteria.

Animal Migration↗

Influence of hippocampectomy on habituation, exploratory behavior, and spatial memory in rats.

Two frequently cited functions of the hippocampus are mediation of spatial memories and habituation. The present investigation employed head-shake response (HSR) as the habituated behavior in intact and bilaterally hippocampectomized rats. This HSR appears to be minimally influenced by spatial cues. These rats were further tested on two behavioral paradigms that make use of spatial cues, namely open field object exploration, and the Morris water maze. The results indicate that hippocampectomized rats revealed habituation of the HSR, but not to objects within the open field. In agreement with previous reports, hippocampectomized rats were severely impaired both in acquiring and recalling the location of the submerged platform in the Morris water maze task. In a separate experiment independent groups of rats were trained on one of these three paradigms, and tissues were collected from hippocampal, prefrontal, and piriform cortices for the measurement of matrix metalloproteinases (MMPs) as markers of neural plasticity. There were significant MMP-9 elevations in the prefrontal and piriform cortices of rats tested using the object exploration task, in the prefrontal and hippocampal cortices of rats that solved the Morris water maze task, but minimal MMP changes in any tissues taken from HSR habituated rats. These results question the hypothesis that habituation is solely mediated by the hippocampus in favor of a process that utilizes different brain structures and degrees of neural plasticity dependent upon task requirements.

Animals↗

[Correlation of the visual and spatially oriented behaviors of white rats following the elaboration of a visual differentiation habit].

Correlation of spatial-motor and visually oriented reactions of white rats was studied by the method of three-side choice. It is shown that after acquisition of the habit of visual differentiation the visual orientation dominates only at taking feeding decision of passing to the passage. The choice of the direction of running to blinds and the choice of place of entering the passage do not depend on present visual signals location and do not reflect the state of visual differentiation habit, but are controlled by spatial memory.

Animals↗

Simulation of spatial learning in the Morris water maze by a neural network model of the hippocampal formation and nucleus accumbens.

Cells in the hippocampal formation show spatial firing correlates thought to be critical to the role played by this structure in spatial learning. Place cells in the hippocampus proper show location-specific activity, whereas cells in the postsubiculum fire as a function of momentary directional heading. One question which has received little attention is how these spatial signals are used by motor structures to actually guide spatial behavior. Here we present a model of how one kind of spatial behavior, instrumental learning in the Morris water maze, could be guided by the spatial information in the hippocampal formation. For this, we concentrate on the hippocampal projection to the nucleus accumbens, which is strongly implicated in instrumental learning. In the model, simulated firing patterns of place cells and head direction cells activate "motor" cells in the "accumbens." Each motor cell causes a particular locomotor movement in a simulated rat. In this way, the "rat" locomotes through the simulated environment. Each step places the animal in a slightly different location and directional orientation, which, in turn, activates a different set of place and head direction cells, thus causing the next locomotor response, and so on. Connection strengths between cells are initially set randomly. When the animal encounters the reward location, however, connections are altered, so that recently active synapses are strengthened. Thus, successful moves in a particular locational and directional context are "stamped in." Simulated rats show rapid learning, similar in many ways to that of actual rats. In particular, they generate efficient routes to the goal after minimal experience, and can do so from somewhat novel starting positions. Consideration of the model architecture shows that 1) combined use of directional and place information is an example of a linearly inseparable problem and that 2) some types of novel route generation, often thought to require a "cognitive mapping" strategy, can be generated from the S-R type model used here.

Animals↗

Characterizing exploration behavior in spatial neglect: omissions and repetitive search.

In search tasks, patients with spatial neglect typically fail to respond to stimuli on the contralesional side. Such behavior has been associated with hyperattention to the ipsilesional side and a deficit in disengaging from attended stimuli. The present study investigated whether such explanations can also account for a further kind of behavior frequently shown by neglect patients: repetitive returns to previously indicated stimuli, particularly on the ipsilesional side. A group of neglect patients was tested along with a group of healthy participants and a patient control group without neglect. Participants performed an exploration task in which they searched for targets defined by their shape or for all stimuli either with the aid of vision or blindfolded. The results showed differential effects of reducing the salience of visual stimuli by blindfolding. For a subgroup of patients, detection rate improved, while for others the percentage of omissions increased. However, contrary to the control groups, blindfolding had no effect on repetitive search in the neglect group, inconsistent with hyperattention, a disengage or impaired working memory deficits. The rate of repetitive returns to previously indicated locations did not seem to be associated with the percentage of omitted stimuli, suggesting that repetitive returns may be best explained by a disruption of systematic search and lack of volitional control in spatial neglect. The results further underline the importance of considering repetitive search behavior in addition to omissions in standard neglect assessments.

Aged↗

Ontogeny of spatial navigation behaviors in the rat: dissociation of "proximal"- and "distal"-cue-based behaviors.

Rats can use both "proximal" and "distal" cues to locate goal objects in their environments (Morris, 1981). In the proximal-cue situation, local stimuli that spatially co-occur with the goal are available to guide behavior. In the distal-cue situation, there are no cues that co-occur with the goal object; thus to directly locate the goal, the rat must learn about the spatial location of the goal relative to distal cues. Using the Morris water maze, we found that these two navigation behaviors are dissociated during ontogeny. Rats only 17-days-old are capable of using proximal cues to locate a safe platform. It was not until the rats were 20-days-old, however, that they began to display minimal evidence of distal-cue utilization. Control experiments indicated that the 17-day-old subjects' failure on the distal problem was likely due to their inadequate spatial learning skills. These results were interpreted within a Jacksonian perspective of brain-behavior relations.

Aging↗

Aging and spatial cognition.

The study of age-related changes in spatial behaviors has much in common with the study of age-related changes in classical conditioning. A comparison is made of research in these two areas, with the suggestion that future work in spatial behaviors pursue the same lines of investigation that have been effective in classical conditioning.

Aging↗

The effects of psychomotor stimulants on single-spatial alternation behavior in dogs.

Dogs were trained to pedal press for drinking water in a noncued, single-spatial alternation task. After the dogs were exhibiting stable performance at or above predetermined criteria levels, they were given three doses of four different drugs (methylphenidate, 0.2, 0.4, and 0.8 mg/kg; d-amphetamine, 0.15, 0.3 and 0.6 mg/kg; cocaine, 0.5, 1, and 2 mg/kg; and phenmetrazine, 0.6, 1.2 and 2.4 mg/kg). In general, all four drugs produced similar changes in performance. The number of correct responses was an especially sensitive indicator of drug effects. All four drugs also produced significant increases in both the average response latency and total session duration, but there were few significant changes in either the total number of responses or number of intertrial interval responses. Relative to d-amphetamine, the potencies of cocaine and phenmetrazine, but not methylphenidate, were generally higher for the measures of single-spatial alternation than for self-administration.

Animals↗

Methamphetamine exposure from postnatal day 11 to 20 causes impairments in both behavioral strategies and spatial learning in adult rats.

Spatial learning and memory deficits in a water maze have been observed in adult animals exposed to a regimen of 4 daily doses of d-methamphetamine (MA) at 2 h intervals from postnatal day 11 to 20. An interpretational issue for these long-term effects of MA is whether they are truly spatial deficits or are secondary to alterations in sensorimotor systems. In this experiment, we evaluated the effects of a pretraining procedure shown to minimize the influence of drug-induced sensorimotor deficits. Animals within a litter were treated with MA or saline. Animals were either pretrained for nonspatial task requirements in the water maze (i.e., swimming and platform climbing) or were nai;ve to the task. Animals that received the pretraining did better than the nai;ve animals. The nai;ve MA animals performed worse than the nai;ve control animals as previously observed. By contrast, no difference in search time was noted between pretrained MA- and SAL-treated animals during the acquisition phase of testing. When the platform was relocated in a novel position, spatial learning was impaired for MA animals, regardless of pretraining. No increase in the number of platform nonrecognition events (swimovers, deflections, or jump-offs) occurred among pretrained or nai;ve groups compared to controls. These data suggest that sensorimotor deficits do not account for the spatial learning and memory deficits in animals exposed neonatally to MA.

Animals↗

Spatial cognition and neuro-mimetic navigation: a model of hippocampal place cell activity.

A computational model of hippocampal activity during spatial cognition and navigation tasks is presented. The spatial representation in our model of the rat hippocampus is built on-line during exploration via two processing streams. An allothetic vision-based representation is built by unsupervised Hebbian learning extracting spatio-temporal properties of the environment from visual input. An idiothetic representation is learned based on internal movement-related information provided by path integration. On the level of the hippocampus, allothetic and idiothetic representations are integrated to yield a stable representation of the environment by a population of localized overlapping CA3-CA1 place fields. The hippocampal spatial representation is used as a basis for goal-oriented spatial behavior. We focus on the neural pathway connecting the hippocampus to the nucleus accumbens. Place cells drive a population of locomotor action neurons in the nucleus accumbens. Reward-based learning is applied to map place cell activity into action cell activity. The ensemble action cell activity provides navigational maps to support spatial behavior. We present experimental results obtained with a mobile Khepera robot.

Animals↗

Taking the intentional stance at 12 months of age.

This paper reports a habituation study indicating that 12-month-old infants can take the "intentional stance" in interpreting the goal-directed spatial behavior of a rational agent. First, we examine previous empirical claims suggesting that the ability to attribute intentions to others emerges during the second half of the first year. It is argued that neither the perceptual evidence (concerning the early ability to discriminate agents), nor the behavioral data (indicating the use of communicative gestures for instrumental purposes) are sufficient to support such claims about the early appearance of a theory of mind, as there are alternative explanations for these phenomena in terms of simpler psychological processes. It is then suggested that to show that an infant indeed attributes an intention to interpret the goal-directed behavior of a rational agent, one needs to demonstrate that the baby can generate an expectation about the most rational future means action that the agent will perform in a new situation to achieve its goal. We then describe a visual habituation study that meets this requirement. The results demonstrate that based on the equifinal structure of an agent's spatial behavior, 12-month-old infants can identify the agent's goal and interpret its actions causally in relation to it. Furthermore, our study indicates that infants of this age are able to evaluate the rationality of the agent's goal-directed actions, which is a necessary requirement for applying the intentional stance. In closing, we discuss some of the theoretical and methodological implications of our study.

Analysis of Variance↗