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Results for “Exploratory Behavior”

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At least 595 records · Page 33Linked to original sources

PubMed1987

Paternal care of infants during maternal separations: associations with father-infant interaction at one year.

Observations of father-infant interaction in the home environment at age one year were compared for two groups of infants that in the months preceding the observations differed in the amount of experience they had with their fathers when the mother was outside the home. The sample consisted of 46 middle-class families, each with a first-born infant (23 males, 23 females). Estimates of the amount of experience the father had with the infant when the mother was outside the home were obtained from detailed maternal interviews that addressed all mother-infant separations. At one year, fathers who provided more extensive care in the absence of the mother showed a higher degree of breadth or variety in their patterns of engaging the infant and higher rates of behavior directed to the infant. These infants showed higher rates of responding to their fathers and more frequent instances of exploratory behavior. Distinctive patterns of differences were evident in the behavior of fathers and infants who had contrasting amounts of experience with each other in social contexts without the mother.

Child Development↗

PubMed2005

Behavioral and neurochemical studies on brain aging in galanin overexpressing mice.

To study possible involvement of galanin in brain aging quality, we have investigated behavioral, neurochemical and morphological parameters in aged mice overexpressing galanin under the platelet-derived growth factor B promoter (GalOE mice) compared to wild-type littermates (WT mice). The behavioral analysis in the forced swim test showed that old GalOE animals spent more time in immobility compared to WT. In the activity cage test, galanin overexpression counteracted the age-induced decrease in exploratory behavior. The neurochemical analysis showed a 30% decrease in noradrenaline overflow in the cerebral cortex of WT old mice that was not present in age-matched GalOE mice. Our results indicate that overexpression of galanin can influence several behavioral and neurochemical parameters in old mice.

Aging↗

PubMed1995

Neonatally administered naltrexone affects several behavioral responses in adult rats of both genders.

The effects of a daily injection of the opioid antagonist naltrexone (NALTX, 1 mg/kg SC), from birth to weaning day, on several behavioral parameters were investigated in adult rats of both genders. This work uses three behavioral tests. The use of the open-field test in addition to the holeboard and plus-maze tests allows the measurement of complementary parameters, and provided further information on diverse components of behavior. The effect of repeated testing (habituation) over 3 consecutive days of open-field testing was also assessed. In accordance with previous reports, female rats showed higher locomotor activity and exploration and a lower level of emotionality than their male counterparts. The response of the animals to repeated testing seemed to be both sex and treatment dependent. In both males and females, NALTX treatment during the preweanling period did not affect locomotor activity, but increased the animals' levels of anxiety and emotionality and decreased exploratory behavior. Our results indicate that neonatal opioids may play an important role in the development of behavioral responses in the adult.

Animals↗

PubMed1985

Behavioral analysis of the effect of substance P injected into the ventral mesencephalon on investigatory and spontaneous motor behavior in the rat.

In the present experiments the behavioral response to substance P (SP) microinfusion into the ventral tegmental area (VTA), substantia nigra (SN), and sensorimotor cortex (CX) was investigated in detail. The experiments were carried out using an eight-hole box to measure exploratory behavior and a video monitor for the analysis of spontaneous motor behavior. When infused into the VTA, SP (0.125, 0.5, 3.0 micrograms) augmented the frequency and total duration of hole-pokes, and tended to diminish the mean duration of hole-pokes. The strategy and organization of responses, as measured by the order of hole-visits and hole-switching, were unchanged by SP and there was no indication of stereotypy, measured by the number of hole-pokes per hole-visit. The open-field analysis revealed a marked increase in locomotion and rearing, both in the periphery and center of the arena; grooming was decreased by SP. The behavioral profile following SN infusions of SP (3.0 micrograms) was similar to that elicited by VTA infusions, with the exception that center rearing was not enhanced. SP administration into cortex (3 micrograms) had no significant effect on any behavioral measures. It is hypothesized that SP infused into the ventral mesencephalon results in an enhancement of approach response tendencies, suggesting that endogenous SP in this region may regulate spontaneous behavior. The possibility of an interaction between SP and meso-telencephalic dopamine neurons is discussed.

Animals↗

PubMed1998

Strain differences in open-field and elevated plus-maze behavior of rats without and with pretest handling.

Behavior of two rat strains was analyzed with and without 1-week pretest handling. Male rats (150-200 g body weight) of the strains PVG/OlaHsd (PVG) and Hsd:Sprague-DawleySD (SPRD) were tested once in a standard open field and an enriched open field and twice in an elevated plus-maze. Behavioral analysis revealed significant differences between the two strains and differential effects of the pretest handling procedure. SPRD rats displayed higher levels of activity and exploratory behavior than the PVG rats, whereas PVG rats were obviously less anxious. One-week pretest handling had an "anxiolytic" effect and changed activity and exploration-related behavior of the animals in both strains. Activity-related parameters were mainly affected in SPRD rats and anxiety-related ones in PVG rats. The data give evidence that differences in behavior of rats are not only determined genetically but also by preceding handling procedures. Because the two rat strains responded differentially to the pretest handling, we recommend to use a well-defined handling procedure before starting a behavioral test, especially when drug applications are included.

Animals↗

PubMed1980

Effects of cerebellar lesions on activity, social interactions, and other motivated behaviors in the rat.

In rats, lesions of the cerebellar fastigial nucleus, but not lateral nuclear lesions or cerebellar cortical lesions, resulted in significant reductions in activity, open-field exploratory behavior, and social interactions. These deficits showed no recovery over a 4-wk testing period and were not related to the motor effects of the lesions. Other motivated behaviors, such as eating, grooming, gnawing, and pain responsiveness, were minimally affected. This pattern of results, together with other findings, suggests the existence of two separate fastigial output pathways to neurobehavioral substrates. One of these is the direct fastigio-bulbar pathway, which mediates the eating, grooming, and gnawing behaviors elicited by fastigial stimulation. The other is the ascending fastigial projection to limbic structures, which may mediate fastigial influences on activity and social interaction.

Animals↗

PubMed1988

A multipurpose vertical holeboard with automated recording of spatial and temporal response patterns for rodents.

A method is presented for manual or automated recording of rats' spontaneous nose-poking ('visit') behaviors to a vertical holeboard with a matrix of 45 or 54 holes. Several behavior parameters are presented: visit frequency, visit duration, temporal visit pattern, spatial visit pattern, stereotype of visits, diversity of visits and variability of visit patterns. The paper describes the development of the apparatus and some methods of analyzing and presenting the multi-parametric data. The use of the apparatus is illustrated with a one-trial appetitive conditioning task. After 5 min in a single 10-min session, a food pellet is presented, only once in a given hole, to provide reinforcement of a spontaneous visit to that hole. The behavior parameters are compared before and after reinforcement. When the one-trial conditioning effect was challenged with d-amphetamine, the behavior parameters changed in a graded manner depending upon the dose (0.25-6.0 mg/kg). The apparatus has also proven useful for studies of exploratory behavior without using food reinforcement following lesion or drug interventions.

Animals↗

PubMed2006

Motor activity (exploration) and formation of home bases in mice (C57BL/6) influenced by visual and tactile cues: modification of movement distribution, distance, location, and speed.

The motor activity of mice in tests of "exploration" is organized. Mice establish home bases, operationally defined as places where they spend long periods of time, near physical objects and nesting material from which they make excursions. This organization raises the question of the extent to which mouse motoric activity is modulated by innate predispositions versus environmental influences. Here the influence of contextual cues (visual and tactile) on the motor activity of C57BL/6 mice was examined: (1) on an open field that had no walls, a partial wall, or a complete wall, (2) in the presence of distinct visual cues, room cues, or in the absence of visual cues (infrared light), and (3) in the presence of configurations of visual and tactile cues. Mice were generally less active in the presence of salient cues and formed home bases near those cues. In addition, movement speed, path distribution, and the number and length of stops were modulated by contextual cues. With repeated tests, mice favored tactile cues over visual cues as their home base locations. Although responses to cues were robust over test days, conditioning to context was generally weak. That the exploratory behavior of mice is affected by experience and context provides insights into performance variability and may prove useful in investigating the genetic and neural influences on mouse behavior.

Animals↗

PubMed2002

A comparison of female and male rats' ETOH-induced ataxia and exploration following restraint or swim stress.

Animal models of stress reactivity are often employed in developing treatments for humans. Many studies use shock stress, and most use male rats. These experiments compare female and male rats exposed to either restraint stress (RS) or ambient-temperature swim stress (SS), using two durations of each stressor and naive controls. The ataxic effects of a 0.6 g/kg i.p. dose of ethanol (ETOH) were measured. Females exhibited less ataxia than males following ETOH administration. There were no significant effects of stress on ETOH-induced ataxia. Exploration was also measured in an open-field test (OFT) both pre- and poststress. In the prestress OFT, females were more active than males. For the no-stress groups and the shorter-duration stress groups, exploration decreased between the first and second OFTs. However, the groups exposed to the longer-duration stress did not show this expected decrease in exploration. A key finding of this research is that while sex differences may be present at baseline, the sexes may react similarly to stress. These data extend knowledge on sex differences in stress, alcohol reactivity and exploratory behavior.

Animals↗

PubMed1983

Lithium chloride and avoidance of novel places.

Rats were exposed to a distinctive chamber (chamber A, part of a two-chamber apparatus), which was novel for half of the rats but familiar for the other half. Each rat was subsequently injected with lithium chloride or saline. In a test trial conducted 24 hr later, all rats were given a choice between chamber A and a second chamber (B), which was novel for all rats. The main result was that the group made familiar with chamber A and then given lithium showed a significant preference for that side or an avoidance of the novel side, a "spatial neophobia." A second experiment confirmed the spatial neophobia effect and demonstrated that it was not dependent on the particular conditioning procedure used in the first experiment. The spatial neophobia effect was related to similar effects in the taste aversion literature, and to the results of research on lithium-induced decreases in exploratory behavior.

Animals↗

PubMed1983

Influence of perinatal malnutrition on adult physiological and behavioral reactivity in rats.

A series of experiments examined the behavioral and pituitary-adrenal response to novelty of perinatally malnourished rats tested as adults after nutritional rehabilitation begun at weaning. Neither the behavioral measures of ambulation, rearing and defecation, nor the plasma corticosterone response to a brief exposure to an open field differentiated the previously malnourished subjects from controls. Similar to controls, previously malnourished subjects were also capable of displaying a graded corticoid elevation to environments increasingly different from the home cage. However, exploratory behavior, as measured by head-dip frequency and duration in the hole-board, was reduced in the previously malnourished rats. Although latency and amount of fluid consumed in a novel environment did not differ, previously malnourished rats were unable to use the cues associated with a consummatory behavior to modulate the pituitary-adrenal response to novelty. Thus, perinatal malnutrition does not influence either the behavioral or physiological activational response to novel stimulation but appears to alter the ability of the animal to use a consummatory behavior to modulate this response.

Animals↗

PubMed1999

Behavioral profiles displayed by rats in an elevated asymmetric plus-maze: effects of diazepam.

When rats are exposed to unknown environments where novelty and fear-inducing characteristics are present (conflictive environments), some specific behaviors are induced and exploration is apparently modulated by fear. In our laboratory, a new type of plus-maze was designed as a model of conflictive exploration. The maze is composed of four arms with different geometrical characteristics, differing from each other by the presence or absence of walls. The degree of asymmetry was as follows: NW, no wall arm; SW, a single high wall present; HL, a low and a high wall present, and HH, two high walls present. The four arms were arranged at 90 degrees angles and the apparatus was called the elevated asymmetric plus-maze (APM). The purpose of the present study was to assess the behavioral profile of rats exposed for a single time to the APM with or without treatment with benzodiazepine. Increasing doses of diazepam were injected intraperitoneally in several groups of male, 90-day-old Holtzman rats. Distilled water was injected in control animals. Thirty minutes after treatment all rats were exposed singly to a 5-min test in the APM. Diazepam induced a biphasic modification of exploration in the NW and SW arms. The increase in the exploration score was evident at low doses of diazepam (0.25-1.0 mg/kg body weight) and the decrease in exploration was found with the higher doses of diazepam (2.0-3.0 mg/kg body weight). Non-exploratory behaviors (permanency) were not affected by benzodiazepine treatment. In the HL arm, exploration was not modified but permanency was increased in a dose-dependent manner. In the HH arm, exploration and permanency were not affected. Results are compatible with the idea that exploration-processing mechanisms in conflictive environments are modulated by fear-processing mechanisms of the brain.

Animals↗

PubMed2003

Maternal influenza infection causes marked behavioral and pharmacological changes in the offspring.

Maternal viral infection is known to increase the risk for schizophrenia and autism in the offspring. Using this observation in an animal model, we find that respiratory infection of pregnant mice (both BALB/c and C57BL/6 strains) with the human influenza virus yields offspring that display highly abnormal behavioral responses as adults. As in schizophrenia and autism, these offspring display deficits in prepulse inhibition (PPI) in the acoustic startle response. Compared with control mice, the infected mice also display striking responses to the acute administration of antipsychotic (clozapine and chlorpromazine) and psychomimetic (ketamine) drugs. Moreover, these mice are deficient in exploratory behavior in both open-field and novel-object tests, and they are deficient in social interaction. At least some of these behavioral changes likely are attributable to the maternal immune response itself. That is, maternal injection of the synthetic double-stranded RNA polyinosinic-polycytidylic acid causes a PPI deficit in the offspring in the absence of virus. Therefore, maternal viral infection has a profound effect on the behavior of adult offspring, probably via an effect of the maternal immune response on the fetus.

Acoustic Stimulation↗

PubMed2004

Role of locus coeruleus alpha1-adrenoceptors in motor activity in rats.

The question of whether or not the locus coeruleus (LC) participates in the control of motor activity has been controversial due to difficulties in demonstrating permanent motor deficits after neurotoxic lesions of this nucleus or of the dorsal noradrenergic bundle (DNB). In the present experiments it was shown in rats that acute local blockade (with terazosin) or stimulation (with phenylephrine) of LC alpha(1)-adrenoceptors respectively blocked or stimulated exploratory behavior in a novel cage and the home cage. Moreover, previous lesion of the DNB by i.p. DSP4 abolished the behavioral changes to local LC alpha(1)-receptor manipulation but did not affect motor activity in the novel or home cage by itself. These findings are consistent with the hypothesis that the intact LC does contribute to motor activity control, exerted in part by its alpha(1)-receptors; however, the permanent loss of this nucleus is compensated for by remaining CNS motor structures.

Adrenergic alpha-Agonists↗

PubMed2005

Anxiolytic-like actions of the hexane extract from leaves of Annona cherimolia in two anxiety paradigms: possible involvement of the GABA/benzodiazepine receptor complex.

A hexane extract of leaves of Annona cherimolia produced anxiolytic-like actions when administered to mice and tested in two animal models of anxiety: the mouse avoidance exploratory behavior and the burying behavior tests. In order to discard unspecific drug-actions on general activity, all treatments studied in the anxiety paradigms were also analyzed in the open field test. Results showed that A. cherimolia induced anxiolytic-like actions at the doses of 6.25, 12.5, 25.0 and 50.0 mg/kg. Picrotoxin (0.25 mg/kg), a GABA-gated chloride ion channel blocker, antagonized the anxiolytic-like actions of A. cherimolia, while a sub-effective dose of muscimol (0.5 mg/kg), a selective GABA(A) receptor agonist, facilitated the effects of a sub-optimal dose of A. cherimolia (3.12 mg/kg). Thus, the involvement of the GABA(A) receptor complex in the anxiolytic-like actions of A. cherimolia hexane extract is suggested. In addition the extract was also able to enhance the duration of sodium pentobarbital induced sleeping time. Taken together, results indicate that the hexane extract of A. cherimolia has depressant activity on the Central Nervous System and could interact with the GABA(A) receptor complex. On the other hand, the chromatographic separation of this extract led to the isolation of palmitone, and beta-sitosterol as major constituents. In addition a GC-MS study of some fractions revealed the presence of several compounds such beta-cariophyllene, beta-selinene, alpha-cubebene, and linalool that have been reported to show effects on behavior that could explain some of the extract effects.

Animals↗

PubMed1989

Evidence for adenosine A2 receptor involvement in the hypomobility effects of adenosine analogues in mice.

The hypomobility induced by a series of adenosine analogues was investigated using a holeboard test and their behavioral potencies correlated to their reported adenosine A1 and A2 receptor affinities. All of the adenosine analogues dose dependently inhibited both exploratory behavior (head dipping) and locomotor activity. The rank order of potency 5'-ethylcarboxamido adenosine (NECA) greater than 5'-methylcarboxamido adenosine (MECA) greater than N6-[(R)-1-methyl-2-phenylethyl]adenosine (R-PIA) greater than N6-cyclohexyladenosine (CHA) = N6-cyclopentyladenosine (CPA) greater than N6-[(S)-1-methyl-2-phenylethylladenosine (S-PIA) greater than N6-(2-hydroxyethyl)adenosine (2-OH-ethyl) was observed for inhibiting both activities. The behavioral potency of these adenosine analogues correlates extremely well with their reported A2 receptor affinity (r2 = 0.93, P less than 0.01 and r2 = 0.86, P less than 0.05 for locomotor and head dipping activity respectively), but very poorly with their reported A1 receptor affinity (r2 less than 0.02, P greater than 0.50 for both activities). These results suggest that adenosine A2 receptors, but not A1 receptors, may be involved in the hypomobility induced by adenosine analogues.

Adenosine↗

PubMed1990

Intracerebroventricular administration of interleukin-1 to mice alters investigation of stimuli in a novel environment.

The behavior of mice administered recombinant interleukin-1 (IL-1) was observed in a novel multicompartment chamber. Doses of human IL-1 alpha (4 pg to 40 ng) injected intracerebroventricularly (ICV) 20 min before testing significantly reduced the mean time mice spent in contact with novel stimuli. No other behavior scored (locomotor activity, grooming, scratching) was significantly affected. Similar results were obtained with murine IL-1 alpha (770 pg or 77 ng) and hIL-1 beta (1 pg to 10 ng). This behavioral change resembled that induced following restraint or ICV injection of corticotropin-releasing factor (CRF). The behavioral effect of ICV IL-1 was lost after it was heated for 10 min at 100 degrees C. Neither the CRF antagonist, alpha-helical CRF9-41 (10 or 20 micrograms ICV) nor the prostaglandin synthesis inhibitor indomethacin (50 mg/kg IP) significantly altered the hIL-1 alpha-induced behavioral changes, but naloxone (0.7 mg/kg SC) or sulpiride (5 mg/kg IP) completely prevented them. Our results suggest that intracerebral administration of IL-1 reduces the exploratory behavior of mice. This effect does not apparently involve CRF or prostaglandins, but may involve opioid and dopaminergic systems. This behavioral response to IL-1 administration is consistent with the behavioral effects of IL-1 reported previously, and strengthens the hypothesis that IL-1 secretion may be responsible for behavioral changes associated with immune activation.

Animals↗

PubMed1992

Purposive behavior and cognitive mapping: a neural network model.

This study presents a real-time, biologically plausible neural network approach to purposive behavior and cognitive mapping. The system is composed of (a) an action system, consisting of a goal-seeking neural mechanism controlled by a motivational system; and (b) a cognitive system, involving a neural cognitive map. The goal-seeking mechanism displays exploratory behavior until either (a) the goal is found or (b) an adequate prediction of the goal is generated. The cognitive map built by the network is a topological map, i.e., it represents only the adjacency, but not distances or directions, between places. The network has recurrent and non-recurrent properties that allow the reading of the cognitive map without modifying it. Two types of predictions are introduced: fast-time and real-time predictions. Fast-time predictions are produced in advance of what occurs in real time, when the information stored in the cognitive map is used to predict the remote future. Real-time predictions are generated simultaneously with the occurrence of environmental events, when the information stored in the cognitive map is being updated. Computer simulations show that the network successfully describes latent learning and detour behavior in rats. In addition, simulations demonstrate that the network can be applied to problem-solving paradigms such as the Tower of Hanoi puzzle.

Animals↗