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 1,045 records · Page 58Linked to original sources
PubMed1995

Head direction cells recorded in the anterior thalamic nuclei of freely moving rats.

Previous studies have identified neurons in the postsubiculum which discharge as a function of the animal's head direction in the horizontal plane, independent of its behavior and location in the environment. Anatomical studies have shown that the postsubiculum contains reciprocal connections with the anterior thalamic nuclei (ATN). In order to determine how the head direction (HD) cell signal is processed in the brain, single-unit recordings were monitored in the ATN of freely moving rats in order to characterize their behavioral and spatial correlates. Animals were trained to retrieve food pellets thrown randomly into a cylindrical apparatus containing a single orientation cue. Single unit recordings in the ATN showed that approximately 60% of the recorded cells discharged in relation to the animal's head direction in the horizontal plane. Observation of the animal and quantitative analyses showed that HD cell firing was not dependent on the animal's behavior, trunk position, linear speed, angular head velocity, or location in the environment. Most of these cells were localized to the anterior dorsal thalamic nucleus. Each HD cell contained only one head direction at which the cell discharged maximally and the firing rate decreased linearly away from this preferred direction. The preferred firing directions from all cells recorded were distributed over a 360 degrees range. Quantitative analysis showed that these cells contained similar discharge parameters (peak firing rate, directional firing range) to values reported previously for postsubicular HD cells (Taube et al., 1990a). Experiments involving rotation of the orientation cue showed that the preferred firing direction could be controlled by a salient visual cue. In contrast to postsubicular HD cells, passive rotation of a restrained animal showed that most ATN HD cells ceased discharging when the animal's head was oriented in the preferred direction. These findings demonstrate the presence of HD cells in the ATN and indicate the potential importance of this area for spatial navigation. The origin of the head direction signal is discussed and it is concluded that because of the presence of reciprocal connections between the postsubiculum and the ATN, further studies are required in order to determine the direction in which this head-directional information is flowing. Finally, ATN HD cells differ from postsubicular HD cells by appearing to require volitional motoric input.

Animals↗
PubMed1995

Place cells recorded in the parasubiculum of freely moving rats.

Previous studies have identified neurons in the hippocampus, subiculum, and entorhinal cortex which discharge as a function of the animal's location in the environment. In contrast, neurons in the postsubiculum and anterior thalamic nucleus discharge as a function of the animal's head direction in the horizontal plane, independent of its behavior and location in the environment. Because the parasubiculum (PaS) has extensive connections, either directly or indirectly, with these structures, it is centrally located to influence the neuronal activity in these areas. This study was therefore designed to determine the types of behavioral and spatial correlates in neurons from the PaS. Single unit recordings were conducted in the PaS of freely moving rats trained to retrieve food pellets thrown randomly into a cylindrical apparatus. A total of 10.3% of the cells were classified as place cells because they discharged in relation to the animal's location in the cylinder. A large percentage of cells (41.4%) were classified as theta cells. The remaining cells had nondiscernable behavioral correlates. Quantitative analysis of the firing rate maps for the place cells showed they had higher levels of background activity and contained larger firing fields than values reported previously for hippocampal place cells. Directional analysis showed that only three out of 16 cells contained a secondary directional correlate; the firing rate for the remaining cells was not affected by the animal's directional heading within the firing field. A time shift analysis, which shifted the spike time series relative to the animal location series, was conducted to determine whether the quality of the location-specific firing could be improved. The time shifts for three different spatial parameters were optimal when cell discharge led the animal's position. Furthermore, the optimal time shifts for two of these parameters (firing area and information content) were less than the optimal shift reported for hippocampal place cells and suggested that PaS cell discharge lagged behind hippocampal place cell activity. Rotation of the cue card with the animal out of view led to near equal rotation of the firing field when the animal was returned to the apparatus. These results indicate that a small population of cells in the PaS encode the animal's location in its environment, although the representation of space encoded by these cells is different from the type of representation encoded by hippocampal place cells.

Animals↗
PubMed2005

Attention and interhemispheric transfer: a behavioral and fMRI study.

When both detections and responses to visual stimuli are performed within one and the same hemisphere, manual reaction times (RTs) are faster than when the two operations are carried out in different hemispheres. A widely accepted explanation for this difference is that it reflects the time lost in callosal transmission. Interhemispheric transfer time can be estimated by subtracting RTs for uncrossed from RTs for crossed responses (crossed-uncrossed difference, or CUD). In the present study, we wanted to ascertain the role of spatial attention in affecting the CUD and to chart the brain areas whose activity is related to these attentional effects on interhemispheric transfer. To accomplish this, we varied the proportion of crossed and uncrossed trials in different blocks. With this paradigm subjects are likely to focus attention either on the hemifield contralateral to the responding hand (blocks with 80% crossed trials) or on the ipsilateral hemifield (blocks with 80% uncrossed trials). We found an inverse correlation between the proportion of crossed trials in a block and the CUD and this effect can be attributed to spatial attention. As to the imaging results, we found that in the crossed minus uncrossed subtraction, an operation that highlights the neural processes underlying interhemispheric transfer, there was an activation of the genu of the corpus callosum as well as of a series of cortical areas. In a further commonality analysis, we assessed those areas which were activated specifically during focusing of attention onto one hemifield either contra- or ipsilateral to the responding hand. We found an activation of a number of cortical and subcortical areas, notably, parietal area BA 7 and the superior colliculi. We believe that the main thrust of the present study is to have teased apart areas important in interhemispheric transmission from those involved in spatial attention.

Adult↗
PubMed2005

Dissociable retrosplenial and hippocampal contributions to successful formation of survey representations.

During everyday navigation, humans encounter complex environments predominantly from a first-person perspective. Behavioral evidence suggests that these perceptual experiences can be used not only to acquire route knowledge but also to directly assemble map-like survey representations. Most studies of human navigation focus on the retrieval of previously learned environments, and the neural foundations of integrating sequential views into a coherent representation are not yet fully understood. We therefore used our recently introduced virtual-reality paradigm, which provides accuracy and reaction-time measurements precisely indicating the emergence of survey knowledge, and functional magnetic resonance imaging while participants repeatedly encoded a complex environment from a first-person ground-level perspective. Before the experiment, we gave specific instructions to induce survey learning, which, based on the clear evidence for emerging survey knowledge in the behavioral data from 11 participants, proved successful. Neuroimaging data revealed increasing activation across sessions only in bilateral retrosplenial cortices, thus paralleling behavioral measures of map expertise. In contrast, hippocampal activation did not follow absolute performance but rather reflected the amount of knowledge acquired in a given session. In other words, hippocampal activation was most prominent during the initial learning phase and decayed after performance had approached ceiling level. We therefore conclude that, during navigational learning, retrosplenial areas mainly serve to integrate egocentric spatial information with cues about self-motion, whereas the hippocampus is needed to incorporate new information into an emerging memory representation.

Adult↗
PubMed2004

Ethological analyses of crayfish behavior: a new invertebrate system for measuring the rewarding properties of psychostimulants.

Recent investigations in invertebrate neurobiology have opened up a new line of research into the basic behavioral, neurochemical and genomic alterations that accompany psychostimulant drug exposure. However, the extent to which such findings relate to changes in motivational and learning processes, such as those that typify drug addictions, remains unclear. The present study addressed this issue in the crayfish, Orconectes rusticus. The first set of experiments demonstrated that intramuscular injections of cocaine and amphetamine have robust and distinguishable effects on crayfish behavior. In the second part of the study, the reinforcing properties of psychostimulants were tested in a series of conditioned place preference experiments. Amphetamine and, to a lesser extent, cocaine were both found to serve as rewards when their intra-circulatory infusion was coupled to a distinct visual environment. The monoaminergic regulation of behavior has been extensively studied in decapod crustaceans and the present experiments demonstrated that (mammalian) drugs of abuse, capable of interfering with monoamine chemistry, are similarly rewarding to crayfish. Behavioral studies in crayfish can provide a complementary approach to using other invertebrate species in addiction research.

Amphetamine↗
PubMed2005

Comparison of the impact of melatonin on chronic ethanol-induced learning and memory impairment between young and aged rats.

Chronic alcohol exposure causes functional and structural changes in nervous system which have all been associated with learning and memory impairments. Furthermore, alcohol consumption has been shown to alter the pattern of neural cell adhesion molecules (NCAM) which are involved in memory processes. In the current work, we investigated the effects of melatonin on learning and memory deficits induced by alcohol exposure in young and aged rats. A group of young rats (3 months old) were administered ethanol for 45 days and half of them were co-treated with melatonin. Similar treatments were performed in the aged (19 months old) rats. Morris water maze test and passive avoidance task were used to assess cognitive performance. Lipid peroxidation (LPO) and glutathione (GSH) levels were determined to characterize the level of oxidative stress in the hippocampus and cortex. NCAM levels were determined by Western blotting in the hippocampal homogenates. There was a significant elevation in LPO levels and a reduction in GSH levels in aged and alcohol-exposed rats. Furthermore, both young and aged rats displayed some cognitive impairment when given with alcohol for 45 days. Co-administration of melatonin with ethanol significantly reduced LPO and elevated GSH levels while improving the learning and memory deficits induced by ethanol; the aged rats exhibited a greater response to melatonin supplementation. Moreover, melatonin modulated NCAM expression in hippocampus. Present findings indicate that exposure to ethanol induces learning and memory deficits probably by generating reactive oxygen species and downregulating NCAM 180 in hippocampus of aged rats. Melatonin improves learning and memory deficits and the behavioral responses of rats to melatonin supplementation are age dependent.

Aging↗
PubMed1978

Annual reproductive strategy of the squirrel monkey (Saimiri sciureus).

The physiological and behavioral factors underlying the annual reproductive cycle of the squirrel monkey were evaluated under controlled laboratory conditions. Mating activity following the formation of two social groups served to synchronize the reproductive phases during the subsequent year of observation. Changes in male and female reproductive status were assessed during four designated phases: breeding, pregnancy, lactation and fatting. Behavioral and somatic changes in gonadectomized subjects, living in the social groups, were also evaluated. The variations in behavior and physiology across the year were considered in terms of factors constraining the timing of the natural reproductive pattern.

Animals↗
PubMed1981

A comparison of interpersonal distancing behavior in young and elderly adults.

Differences in cortical activation (arousal), age, and race were used to test several hypotheses on interpersonal distancing behaviors which have implications for intergenerational and cross-cultural interaction. The investigation centered on the relationship of sensory deficits in the elderly to their use of personal space in peer interactions. A comparison of young, white female college students and elderly white females indicated no significant differences in arousal level, but the younger adults used significantly closer distancing behaviors with their peers. However, a similar comparison of elderly white and black females revealed no differences in either arousal level or interpersonal distancing. The findings suggest that interpersonal distancing behaviors may be less influenced by the need for cortical stimulation than by the prevalence of cultural norms. It also suggests that the proxemic behavior of adult college students may be more adolescent than adult in its personal space scheme.

Adult↗
PubMed2005

[Long-term prognosis of unilateral spatial neglect--dissociation between conventional tests and behavioral observation].

The long-term prognosis of unilateral spatial neglect (USN) in three elderly patients with stroke was investigated. Case 1 was a 62-year-old man who had suffered from right putaminal hemorrhage three years ago. Obvious right USN was found soon after the onset. After 6 months of rehabilitation he recovered and became independent in ADL without USN signs in daily circumstances. However, left USN signs appeared in some stressful situations such as traditional poetry-based competition or driving an electrical wheelchair on crowded roads. Case 2 was a 62-year-old man who had suffered from cerebral hemorrhage in the right putamen 6 years ago. He showed left USN soon after the onset, but it disappeared gradually. Cerebral infarction in the left basal ganglia occurred 6 years after the first attack. He showed decline of general attention accompanying left USN. Case 3 was a 70-year-old man who had showed left USN signs 7 years previously. He became independent and disappeared USN signs. However his activities of daily living declined gradually, and mental status became worse. Left USN signs were observed again on USN tests. Left USN was observed in three cases soon after the onset of the first stroke and then disappeared. However, USN signs became obvious in some specific situations. The appearance or disappearance of USN seemed to depend on the relationship among severity of USN, physical and mental functions, and circumstances in which USN was evaluated.

Aged↗
PubMed1998

Acute rise in corticosterone facilitates 5-HT(1A) receptor-mediated behavioural responses.

Corticosterone influences 5-HT1A receptor-mediated responses in the rat hippocampus in vitro: activation of the high affinity mineralocorticoid receptor suppresses 5-HT1A receptor-mediated hyperpolarization, while subsequent activation of lower affinity glucocorticoid receptors enhances the effect of 5-HT. We have tested whether a similar effect of corticosterone exists in vivo. In intact rats, a systemic injection of the specific 5-HT1A receptor agonist, 8-OH-DPAT (8-hydroxy-2-(di-n-propylamino)tetralin), led to increased locomotion and to a less persistent search strategy in the free swim trial of the Morris water maze test. Adrenalectomized rats with a corticosterone-pellet implanted as replacement received an injection of vehicle (predominant mineralocorticoid receptor occupation) or a high dose of corticosterone (both corticosteroid receptor types occupied) 1 h before injection of 8-OH-DPAT. The effect on search strategy, but not on locomotor activity, was less in animals with low corticosterone levels. The results suggest that hippocampal 5-HT1A receptor-mediated responses in vivo are attenuated during predominant activation of the mineralocorticoid receptor and increased after additional transient activation of the glucocorticoid receptor.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2003

Dopamine-dependent responses to cocaine depend on corticotropin-releasing factor receptor subtypes.

The effects on locomotor response to cocaine challenge, acquisition of cocaine conditioned place preference and cocaine-induced dopamine (DA) release in nucleus accumbens and ventral tegmental area by the non-specific corticotropin-releasing factor (CRF) receptors antagonist alpha-helical CRF, the selective CRF receptor subtype 1 antagonist CP-154,526 and the selective CRF receptor subtype 2 antagonist anti-sauvagine-30 (AS-30) were investigated in rats. Both alpha-helical CRF (10 microg, i.c.v.) and CP-154,526 (3 microg, i.c.v.) decreased the cocaine-induced distance travelled, whereas AS-30 (3 microg, i.c.v.) did not show such an effect. The CRF receptor antagonists also have significant effects on stereotype counts induced by cocaine injection, in which the alpha-helical CRF or CP-154,526 but not AS-30 did significantly reduce the stereotype counts. alpha-Helical CRF (10 microg) prior to each injection of cocaine blocked cocaine conditioned place preference with no significant difference observed in the time spent in the drug-paired side between post- and pre-training and both 1 and 3 microg CP-154,526 also had significant inhibitory effects on cocaine-induced place preference. However, pre-treatment with an i.c.v. infusion of AS-30 (1 or 3 microg) prior to each injection of cocaine did not affect the acquisition of conditioned place preference. The alpha-helical CRF and CP-154,526 reduced extracellular DA levels of nucleus accumbens and ventral tegmental area in response to the injection of cocaine. However, both alpha-helical CRF and CP-154,526 did not modify extracellular DA levels under basal conditions. In contrast, the i.c.v. infusion of AS-30 had no effects on either the basal DA or the cocaine-induced increase in DA release in nucleus accumbens and ventral tegmental area. These findings demonstrate that activation of the CRF receptor is involved in behavioral and neurochemical effects of cocaine challenge and cocaine reward and that the role of CRF receptor subtypes 1 and 2 in cocaine-induced locomotion, reward and DA release is not identical. The CRF receptor subtype 1 is largely responsible for the action of the CRF system on cocaine locomotion and reward. These results suggest that the CRF receptor antagonist, particularly the CRF receptor subtype 1 antagonist, might be of some value in the treatment of cocaine addiction and cocaine-related behavioral disorders.

Animals↗
PubMed2005

Behavioural phenotypes of hypomorphic KCC2-deficient mice.

Hyperpolarizing fast inhibitory neurotransmission by gamma-aminobutyric acid and glycine requires an efficient chloride extrusion mechanism in postsynaptic neurons. A major effector of this task in adult animals is the potassium-chloride co-transporter KCC2 that is selectively and abundantly expressed postsynaptically in most CNS neurons. Yet, the role of KCC2 in adult brain at the systems level is poorly known. Here, we characterize the behaviour of mice doubly heterozygous for KCC2 null and hypomorphic alleles that retain 15-20% of normal KCC2 protein levels in the brain. These hypomorphic KCC2-deficient mice were viable and fertile but weighed 15-20% less than wild-type littermates at 2 weeks old and thereafter. The mice displayed increased anxiety-like behaviour in several tests including elevated plus-maze and were more susceptible to pentylenetetrazole-induced seizures. Moreover, the mice were impaired in water maze learning and showed reduced sensitivity to tactile and noxious thermal stimuli in von Frey hairs, hot plate and tail flick tests. In contrast, the mice showed normal spontaneous locomotor activity in open field and Y-maze tests, and intact motor coordination in rotarod and beam tests. The results suggest that requirements for KCC2-dependent fast hyperpolarizing inhibition may differ among various functional systems of the CNS. As shunting inhibition is expected to be intact in KCC2-deficient neurons, these mice may provide a useful tool to study the specific functions and relative importance of hyperpolarizing fast synaptic inhibition in adult CNS that may have implications for human neuropsychiatric disorders, such as epilepsy, pain and anxiety.

Analysis of Variance↗
PubMed2000

Enhanced vulnerability to cocaine self-administration is associated with elevated impulse activity of midbrain dopamine neurons.

Individual differences in responding to a novel environment predict behavioral and neurochemical responses to psychostimulant drugs. Rats with a high locomotor response to a novel environment (HRs) exhibit enhanced self-administration (SA) behavior, sensitization, and basal or drug-induced dopamine release in the nucleus accumbens compared with rats with a low response to the novel context (LRs). In this study, we determined whether such differences in vulnerability to drug addiction might be related to differences in dopamine (DA) neuron activity. Rats were divided into HRs and LRs according to their response to a novel environment and then tested for acquisition of cocaine SA. HRs rapidly acquired cocaine SA (175 microg/kg per infusion), whereas LRs did not. Differences in cocaine SA were not caused by differences in exploratory behavior or sampling because these behaviors did not differ in HRs and LRs self-administering a saline solution. In a separate experiment, we used extracellular single-unit recordings and found that HRs exhibit higher basal firing rates and bursting activity of DA neurons in the ventral tegmental area and, to a lesser extent, in the substantia nigra pars compacta. The greater activity of midbrain DA cells in HRs was accompanied by reduced sensitivity to the inhibitory effects of a DA D2-class receptor agonist, indicating possible subsensitivity of impulse-regulating DA autoreceptors. These results demonstrate that differences in the basal activity of DA neurons may be critically involved in determining individual vulnerability to drugs of abuse.

Action Potentials↗
PubMed2001

Absence of delta -9-tetrahydrocannabinol dysphoric effects in dynorphin-deficient mice.

The involvement of dynorphin on Delta-9-tetrahydrocannabinol (THC) and morphine responses has been investigated by using mice with a targeted inactivation of the prodynorphin (Pdyn) gene. Dynorphin-deficient mice show specific changes in the behavioral effects of THC, including a reduction of spinal THC analgesia and the absence of THC-induced conditioned place aversion. In contrast, acute and chronic opioid effects were normal. The lack of negative motivational effects of THC in the absence of dynorphin demonstrates that this endogenous opioid peptide mediates the dysphoric effects of marijuana.

Analgesia↗
PubMed2003

Activation of mitogen-activated protein kinase/extracellular signal-regulated kinase in hippocampal circuitry is required for consolidation and reconsolidation of recognition memory.

Consolidation and reconsolidation of long-term memory have been shown to be dependent on the synthesis of new proteins, but the specific molecular mechanisms underlying these events remain to be elucidated. The mitogen-activated protein kinase (MAPK) pathway can trigger genomic responses in neurons, leading to changes in protein synthesis, and several studies have identified its pivotal role in synaptic plasticity and long-term memory formation. In this study, we analyze the involvement of this pathway in the consolidation and reconsolidation of long-term recognition memory, using an object recognition task. We show that inhibition of the MAPK pathway by intracerebroventricular injection of the MEK [MAPK/extracellular signal-regulated kinase (ERK)] inhibitor UO126 blocks consolidation of object recognition memory but does not affect short-term memory. Brain regions of the entorhinal cortex-hippocampal circuitry were analyzed for ERK activation, and it was shown that consolidation of recognition memory was associated with increased phosphorylation of ERK in the dentate gyrus and entorhinal cortex, although total expression of ERK was unchanged. We also report that inhibition of the MAPK pathway blocks reconsolidation of recognition memory, and this was shown to be dependent on reactivation of the memory trace by brief reexposure to the objects. In addition, reconsolidation of memory was associated with an increase in the phosphorylation of ERK in entorhinal cortex and CA1. In summary, our data show that the MAPK kinase pathway is required for both consolidation and reconsolidation of long-term recognition memory, and that this is associated with hyperphosphorylation of ERK in different subregions of the entorhinal cortex-hippocampal circuitry.

Animals↗
PubMed2002

Enriched early experiences of mice underexpressing the beta-amyloid precursor protein restore spatial learning capabilities but not normal openfield behavior of adult animals.

We have previously reported severely impaired spatial learning in mutant mice underexpressing a shortened variant of the beta-amyloid precursor protein (beta-APPtheta/theta). This targeted mutation is functionally equivalent to a null mutation. It also disturbs behavioral and neurological maturation with deficits emerging mainly between postnatal day (pd) 11 and 19. Such early tested mice exhibited almost no genotype-related difference in Morris water maze learning, raising the possibility that early handling might have compensated for genetic deficits. To verify this effect, we compared watermaze learning and open field behavior of 66 adult mutant and wildtype mice having been handled during pd 3-27 with that of 70 non-handled mutant and wildtype mice. Neurological testing during pd 3-27 markedly reduced time near wall and improved spatial retention of adult mutants, restoring their learning capabilities to wildtype levels. Early handling did not cure the mutation associated activity deficit in the open field, but mainly increased center field exploration in both mutants and wildtypes. In a follow-up experiment we analyzed whether an early (pd 3-10, n = 22) or middle (pd 11-19, n = 24) period of handling in form of neurological testing had differential effects on adult behavior. Mice handled during pd 11-19 had slightly shorter escape times than mice handled during pd 3-10 but were not significantly different in other behavioral measures. There were no sex related differences. Correlational and factor analysis showed that both the mutation and early handling had pleiotropic behavioral effects, resulting in differentially impaired mutants depending on the test situation. Likewise, early handling affected not only thigmotactic tendencies but also, more subtly, other behavioral components underlying water maze learning. We conclude that early postnatal stimulation can prevent mutation induced learning deficits in adult mice, but probably through other developmental mechanisms than those affected by the mutation. This implies that some behavioral impairments related to beta-APP malfunction may be corrected through simple treatments.

Amyloid beta-Protein Precursor↗
PubMed1989

Visual neglect for far and near extra-personal space in humans.

The possible dissociation of unilateral neglect in far and near extra-personal space was systematically investigated using a modified version of the Wundt-Jastrow area illusion test. This task, which requires no motor response, has been shown to be sensitive to unilateral neglect. Stimuli were presented at two different distances (near and far) to a group of 70 patients with right hemispheric lesion (18 in acute and 52 in chronic stage). Twenty-eight patients evidenced unilateral neglect; that is, they displayed unexpected (i.e., contrary to the known illusory effect) responses when the stimuli were perceived as oriented toward the left side. However, performances in the two conditions were highly correlated and there were no individual instances of dissociation. These results suggest that the presence of a motor response may be necessary to show behavioral dissociations between different parts of extra-personal space.

Adult↗
PubMed2002

Experience-dependent coincident expression of the effector immediate-early genes arc and Homer 1a in hippocampal and neocortical neuronal networks.

The transcription of the immediate-early genes Arc and Homer 1a (H1a) is dynamically regulated in response to synaptic activity; their protein products function at the postsynaptic sites of excitatory synapses. Previous studies demonstrate a role for Arc in the maintenance of long-term potentiation and in memory consolidation processes and indicate a role for H1a in modifying glutamatergic signaling pathways. Using double-label fluorescence in situ hybridization, we demonstrate that Arc and H1a RNA expression is induced strongly in the same neurons of rat hippocampus and neocortex after exploration of a novel environment. These findings support the view that novel experience activates a cell-specific genomic program and that Arc and H1a may function in concert in the structural and functional modifications of dendrites that lead to long-term changes in synaptic efficacy.

3' Untranslated Regions↗