SEARCH · PubMed Health

Results for “Exploratory Behavior”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 397 records · Page 22Linked to original sources

PubMed1979

Decreased locomotor and investigatory exploration after denervation of catecholamine terminal fields in the forebrain of rats.

Exploratory behaviors were examined after bilateral microinjections of 6-hydroxydopamine into two hypothalamic sites that produced different patterns of denervation of forebrain catecholamine terminal fields. After anterolateral injections rats locomoted and reared less in a novel open field, responded abnormally to changes in the degree of novelty of the open field, and investigated a novel object less. These are deficits in exploratory behavior because they were not secondary to the inhibition of open-field behavior by hyperemotionality, by general motor disability, or by the failure to detect novel spaces or objects. Such anterolateral injections produced loss of catecholamine fibers, determined histochemically, in neocortical, hippocampal, anterolateral hypothalamic, mesolimbic, mesocortical, and anteromedioventral striatal terminal fields and loss of dopaminergic perikarya in the A10 and anteromedial A9 cell groups. No deficits in exploratory behaviors occurred, however, after bilateral anteromedial 6-hydroxydopamine injections that denervated neocortical, hippocampal, and anteromedial hypothalamic catecholamine terminal fields. A critical forebrain catecholaminergic innervation for exploratory responses to novel stimuli may be within areas that were denervated by anterolateral but not by anteromedial hypothalamic 6-nydroxydopamine injections. These areas are mesolimbic, mesocortical, anteromedioventral, and anterolateral hypothalamic terminal fields.

Animals↗

PubMed2005

Detection of invariants by haptic touch across age groups: rod length perception.

This study examined the development in the detection of maximum eigenvalues and static moment as invariants, through a task of perceiving rod length without visual information by haptic touch. 34 participants ages 6 to 83 years participated in the experiment. Their exploratory behavior and perceptions of rod length were analyzed by age group (Children: 6 to 12 years old; Young Adult: 21 to 25 years old; Middle Age: 31 to 56 years old; and Older: 65 to 83 years old). A behavior analysis indicated that use of vertical swinging increased for the Young Adult group and decreased with age for the Older group, whereas Children frequently held the rod without wielding. Analysis showed that, by age, differences in coefficients on the maximum eigenvalue and static moment were parallel with an exploratory behavioral change. Finally, the effect of different exploratory behaviors on length perception was discussed.

Adolescent↗

PubMed1975

Effects of immobilization stress on open field behavior and plasma corticosterone levels of aging C57BL/6J mice.

Four age groups of C57BL/6J mice (2.2, 6.2, 12.0, and 23.3 months) were subjected to either immobilization or handling (control) procedures. Open field behavior was observed before and after experimental treatments and plasma corticosterone levels were assessed 11 days following the immobilization or handling procedures. Eleven days following immobilization elevated corticosterone levels were observed for all but the 12.0 month group of mice. No behavioral effects were observed for the experimental groups, although both locomotor activity and exploratory behavior declined with advancing age. The age-related decrease in activity was entirely accounted for by scores on the initial open field test. Exploratory behavior was observed to be a more complex function of both age and experience.

Aging↗

PubMed1984

Abolition of the behavioral effects of cholecystokinin following bilateral radiofrequency lesions of the parvocellular subdivision of the nucleus tractus solitarius.

Cholecystokinin (CCK) has been implicated as a signal for the syndrome of satiety in a variety of species. Several lines of evidence point to a peripheral site of action for the behavioral effects of CCK. Peripheral CCK receptors appear to activate a gut-brain pathway involving the sensory fibers of the vagus nerve. To investigate the central anatomical substrate of this visceral-behavioral control system, the terminal regions of the sensory tract of the vagus were lesioned. Selective destruction of the parvocellular subdivisions of the nucleus tractus solitarius (NTS) blocked the effects of acute doses of CCK on exploratory behaviors. Sham lesions and lesions destroying only the remaining regions of the NTS or the vagal motor nuclei had no effect on baseline exploratory behaviors and did not influence the ability of CCK to decrease spontaneous exploratory behaviors. These findings delineate the first central site along the ascending sensory pathway which appears to mediate the satiety-related behavioral effects of CCK.

Animals↗

PubMed1980

The development of social structure during the primary socialization period in German shepherds.

The ontogeny of primary socialization in a litter of 5 German shepherd puppies was investigated using both arena tests and rearing environment (kennel) conditions. Tests for exploratory behavior, conducted at 5 1/2, 8 1/2, and 11 1/2 weeks of age, showed reversals in amount of exploration over the 6-week period. Dominance was also investigated at 5 1/2, 8 1/2, and 11 1/2 weeks, using both a bone-in-pen test and a rearing environment setting. By comparison of the subjects' dominance scores at each age for both settings, evidence was found for the separation of the development of dominance behavior into 2 kinds: competitive and social dominance. The scores for exploratory behavior (stimulus reactivity) and competitive dominance were clearly related: those pups at 5 1/2, 8 1/1, and 11 1/2 weeks that were most exploratory also ranked highest for competitive dominance.

Age Factors↗

PubMed2001

Do nociceptive signals from the pancreas travel in the dorsal column?

A midline dorsal column lesion has been shown to be an effective surgical treatment for the relief of pelvic visceral pain in patients. The aim of this study was to examine the effectiveness of a dorsal column lesion upon: (i) increased electrophysiological responses of neurons in the ventral posterolateral thalamic nucleus in anesthetized rats evoked by the application of bradykinin to the surface of the pancreas, and (ii) pain-related behaviors observed after pancreatic infusion with bradykinin. In rats anesthetized with pentobarbital, recordings from individual thalamic neurons were made using tungsten electrodes. Brief application of bradykinin (10 microg/ml) to the surface of the pancreas resulted in an increased firing rate in approximately 20% of neurons recorded. A dorsal column lesion or intrathecal administration of morphine greatly reduced the excitatory effects of pancreatic bradykinin application on thalamic neurons. In a separate group of rats, bradykinin was infused into the pancreas through a previously implanted catheter resulting in a decrease in exploratory behavior and an increase in other pain-related behaviors, e.g. licking of the abdomen. A dorsal column lesion made prior (1 week) to the bradykinin infusion reduced the decrease in exploratory behavior but did not return exploratory behavior to control levels. In conclusion, nociceptive information relayed to the thalamus about the pancreas is transmitted from the spinal cord through the dorsal columns, possibly by the post-synaptic dorsal column pathway. However, the dorsal column pathway may not be the sole route for relaying information about noxious stimulation of the pancreas, particularly that impacting complex behavioral responses.

Analgesics, Opioid↗

PubMed1986

Antagonists of central and peripheral behavioral actions of cholecystokinin octapeptide.

Pharmacological studies on the behavioral functions of sulfated cholecystokinin (CCK) in the gut and in the brain require potent, specific antagonists to CCK. Compounds identified as competitive antagonists at the peripheral receptors for CCK were tested for their ability to block the behavioral effects of CCK administered centrally and peripherally. Behavioral effects of CCK (8.8 X 10-10 mmol) administered centrally into the nucleus accumbens, i.e., potentiation of dopamine-induced hyperlocomotion in rats, were effectively blocked by pretreatment with proglumide (6 X 10(-5) mmol of nucleus accumbens), by benzotript (3 X 10(-5) mmol of nucleus accumbens) and by rabbit antiserum raised against CCK (0.2 microliter/nucleus accumbens), but not by CCK26-33 (1.7 X 10(-7) mmol) or unsulfated CCK26-33 (1.9 X 10(-6) mmol). The behavioral effects of peripherally administered CCK, i.e. reduced food consumption and reduced exploratory behaviors in mice, were blocked effectively by pretreatment with proglumide (0.3-0.9 mmol/kg), and by benzotript (0.03 mmol/kg), but not by CCK30-33 (0.003 mmol/kg). None of the compounds administered peripherally significantly affected food consumption or exploratory behaviors when given alone. Furthermore, none of the compounds significantly affected locomotion when administered alone into the nucleus accumbens, or significantly affected dopamine-induced hyperlocomotion when given into the nucleus accumbens before dopamine. Benzotript, proglumide and a CCK antibody appear to act as specific antagonists of the behavioral effects of CCK at both the peripheral gastrointestinal site and at the central nucleus accumbens site. Neither unsulfated CCK26-33 or CCK30-33 were effective as antagonists of peripheral or central behavioral effects of CCK. However, whereas benzotript and proglumide may be useful as pharmacologically specific antagonists, the high doses required suggest that more potent CCK antagonists are required for investigating the behavioral functions of endogenous CCK.

Animals↗

PubMed1983

Behavioral and neurochemical effects of neurotensin microinjection into the ventral tegmental area of the rat.

The ventral tegmental area of the rat brain has been shown to possess high densities of neurotensin- and dopamine-containing neuronal perikarya. We recently demonstrated that microinjection of neurotensin into the ventral tegmental area produces behavioral hyperactivity similar to amphetamine-induced increase in exploratory behaviors, but lacking stereotypies. In this study, we report that the threshold dose for neurotensin-induced hyperactivity is 0.10-0.25 micrograms neurotensin/side. Either intracerebroventricular injection of haloperidol (5.0 micrograms/lateral ventricle) or destruction of the mesolimbic dopamine system by 6-hydroxydopamine abolishes the behavioral hyperactivity produced by intraventral tegmental injection of neurotensin (2.5 micrograms/side). Using high pressure liquid chromatography with electrochemical detection, we show that neurotensin injection into the ventral tegmental area increases the concentration of dopamine metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the nucleus accumbens and olfactory tubercles, but not in the striatum. This effect is especially profound in the nucleus accumbens where the threshold dose is less than 0.025 micrograms/side. The ratio of 3,4-dihydroxyphenylacetic acid to dopamine increased in the nucleus accumbens and olfactory tubercles in a dose-dependent fashion (0.025 microgram-2.50 micrograms/side). Neurotensin-induced behavioral hyperactivity correlates positively with neurotensin-induced changes in the ratio of 3,4-dihydroxyphenylacetic acid to dopamine. This study indicates that neurotensin acts in the ventral tegmental area to activate the mesolimbic dopamine system. Further, this activation produces behavioral hyperactivity characterized by an increase in exploratory behaviors. The fact that both immunoreactive neurotensin and neurotensin receptors are found in high concentration in the ventral tegmental area supports the possible physiological significance of this peptide-catecholamine interaction.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2003

Increased hippocampal uptake of tumor necrosis factor alpha and behavioral changes in mice.

Brain trauma may alter the function of the blood-brain barrier (BBB) and affect psychomotor activity. We have shown that the transport system for tumor necrosis factor alpha (TNF alpha) at the BBB undergoes regulatory changes after spinal cord injury. In this study, we show in CD1 mice that mild trauma by weight-drop to the right temporal region specifically increases the uptake of blood-borne TNF alpha. This increase, measured by use of radiolabeled murine TNF alpha, occurred only in the right hippocampus 24 h after injury and returned to normal at 1 week. There was no increase in the uptake of the vascular marker albumin at 1 h, 24 h, or 1 week postinjury, indicating that the BBB remained relatively intact. Human interleukin-1 beta, which does not cross the BBB by saturable transport, showed no significant changes in brain uptake after trauma. Therefore, the selective entry of TNF alpha in the injured right hippocampus may be explained by enhanced transport across the BBB. To explore the functional relevance of this transport regulation, we measured mouse behavior by the staircase test. The number of rearings, mainly reflective of exploratory behavior, decreased at 1 h and 1 day after injury but increased at 1 week after a 30-g weight-drop injury. The number of stairs ascended, mainly indicative of locomotor activity, was unchanged at all times tested. We conclude that mild, blunt brain trauma involving the hippocampus causes specific upregulation of TNF alpha transport and a selective change in exploratory behavior. Although no causal relationship can be established at this time, the behavioral changes might be related to the increased TNF alpha transport after trauma.

Animals↗

PubMed2005

Effect of different illumination levels on rat behavior in the elevated plus-maze.

The present study addressed the role of environmental light intensity on the exploratory behavior of rats in the elevated plus-maze, with the specific goal of determining the light intensity threshold for triggering the aversion to the open arms. Male Wistar-derived rats were tested in the elevated plus-maze under different illumination levels: 0, 1, 3, 10, 30, 100 and 300 lx. Exploratory behavior occurring in the open arms (e.g., entries and time spent in these arms) was more intense under 0 and 1 lx than under the other illumination levels, which did not differ among themselves; on the other hand, locomotor behavior (as indicated by frequency of entries and distance run in the closed arms) was not altered under all illumination conditions. The data indicated that vision is important in triggering aversion to the open arms of the elevated plus-maze. They also indicated that the threshold of such aversion was found between 1 and 3 lx environmental illumination and that the phenomena is not intensity-dependent but rather of an all-or-none type. It should be emphasized that these conclusions only stand for unfamiliar environments. The role of light in familiar environments is currently under investigation in our laboratory.

Analysis of Variance↗

PubMed2005

Neurochemical effects of cocaine in adolescence compared to adulthood.

Adolescence is a time of high risk behavior and increased exploration. This developmental period is marked by a greater probability to initiate drug use and is associated with an increased risk to develop addiction and adulthood dependency. Human adolescents are predisposed toward an increased likelihood of risk taking behaviors [M. Zuckerman, Sensation-seeking and the endogenous deficit theory of drug abuse. NIDA Res Monogr. 74 (1986) 59-70.], including drug use or initiation. In the present study, adolescent and adult animals were first tested on several behavioral measures (novel environment exploratory behavior, novel object preference, novelty-induced impulsivity and novelty-induced exploration) which were used to categorize them as high- (HR) or low-responders (LR). The purpose of the present study was to characterize the neurochemical responsivity of the nucleus accumbens septi (NAcc) in HR and LR adolescent and adult animals in response to a systemic challenge of cocaine. Regardless of age, animals that were more reactive when placed in a novel environment had greater cocaine-induced increases in dopamine (DA). Several important and complex neurochemical differences existed between adolescent and adult animals. Adolescent animals that rapidly approached the novel object (i.e., HR) were the only group to show greater cocaine-induced responsivity. However, adult animals that spent less time near the novel object (i.e., LR) were the only group to have greater cocaine-induced responsivity. Adolescent animals that approached a novel object faster (HR) showed an increased dopaminergic (DAergic) response to an acute cocaine challenge. In contrast, adolescent animals that spent less time with the novel object had an increased cocaine-induced DAergic response compared to HR adults. Adults that approached the object less had a greater cocaine-induced DA response relative to HR adults. Finally, cocaine yielded a greater DA response in adolescent animals that showed a high novelty-induced exploration and impulsivity response, whereas the opposite was true for adults. The differences in response to cocaine between ages and groups are likely due to ontogenetic differences in brain regions that are involved in reward and/or stress responsivity.

Age Factors↗

PubMedDate not supplied

Long-term habituation to spatial novelty in blind cave fish (Astyanax hubbsi): role of the telencephalon and its subregions.

Blind cave fish, when released into a novel environment, show a typical exploratory behavior characterized by high swim speed along walls shortly after release. This behavior wanes during prolonged exposure and thus may reflect habituation to novelty. As the hippocampus of mammals, which plays a crucial role in spatial learning, is part of the telencephalon, the possible involvement of this brain structure of fish was investigated in exploratory behavior. Ablation of the whole telencephalon or bilateral removal of dorsal parts of the hemispheres reduced activity; in contrast, unilateral lesions of one hemisphere, bilateral lesions of dorsal and dorsoventral parts, and removal of olfactory bulbs increased activity. However, the time course of habituation in a novel environment remained unchanged, except for ablated animals in which there was virtually no habituation in swim speed. These data suggest that the telencephalon of fish may not participate in long-term habituation to spatial novelty but, rather, support the notion of the telencephalon being involved in generation of arousal.

Animals↗

PubMedDate not supplied

Developmental lead exposure: behavioral alterations in the short and long term.

Wistar dams were exposed to 500 ppm of Pb, as Pb acetate, or 660 ppm Na acetate in drinking water during pregnancy and lactation. Male pups at 23 (weaned) or 70 days (adult) of age were submitted to behavioral evaluation and Pb determination. The behaviors evaluated were: locomotor activity (open-field test), motor coordination (rotarod test), exploratory behavior (holeboard test), anxiety (elevated plus maze and social interaction tests), and learning and memory (shuttle box). Pb levels were measured in the blood and cerebral regions (hippocampus and striatum) of dams and pups. The results of the present report demonstrated that exposure to Pb during pregnancy and lactation induces in weaned pups hyperactivity, decreased exploratory behavior, and impairment of learning and memory. These alterations were observed at blood Pb levels in the range that may be attained in children chronically exposed to low levels of Pb (21+/-3 microg/dl). Regarding adults, the results demonstrated that the regimen of exposure adopted induces anxiety in these animals at nondetectable blood Pb levels.

Aging↗

PubMed2006

Fornix transection impairs exploration but not locomotion in ambulatory macaque monkeys.

Prompted by the theoretical prediction that damage to the hippocampal system should abolish exploratory behavior, the present study examined exploratory movements in control monkeys (CON) and monkeys with transection of the fornix (FNX), a major input/output pathway of the hippocampus. CON and FNX monkeys were introduced to a novel octagonal chamber for six daily sessions, each lasting 20 min. Both groups visited, punctuated by stops, the majority of the floor space of the environment in each of the sessions. The exploratory movements of CON and FNX groups were not significantly different on most of the measures taken over six consecutive days. These measures included cumulative distance traveled, number and duration of stops, traveling patterns, and proportion of time spent in each of 12 designated zones of floor space. The high degree of similarity in behavior between CON and FNX groups suggests that an intact hippocampal system is not necessary for the display of normal exploratory movement per se. On the other hand, the CON and FNX groups did behave differently on two measures. First, the CON group exhibited a decrement in distance traversed over consecutive epochs within the first test session, whereas FNX animals did not. Second, on those days in which the chamber was made visually asymmetrical, the CON animals tended to show a predilection for spending proportionally more time within one particular quadrant of the chamber. These observations are consistent with the idea that interrupting normal hippocampal system function by means of fornix transection is detrimental to learning about the spatial layout of environments. We therefore suggest that while monkeys with fornix transection still display intact locomotor and exploratory behavior patterns, their new learning of visuospatial context is impaired.

Animals↗

PubMed2005

A circuit for navigation in Caenorhabditis elegans.

Caenorhabditis elegans explores its environment by interrupting its forward movement with occasional turns and reversals. Turns and reversals occur at stable frequencies but irregular intervals, producing probabilistic exploratory behaviors. Here we dissect the roles of individual sensory neurons, interneurons, and motor neurons in exploratory behaviors under different conditions. After animals are removed from bacterial food, they initiate a local search behavior consisting of reversals and deep omega-shaped turns triggered by AWC olfactory neurons, ASK gustatory neurons, and AIB interneurons. Over the following 30 min, the animals disperse as reversals and omega turns are suppressed by ASI gustatory neurons and AIY interneurons. Interneurons and motor neurons downstream of AIB and AIY encode specific aspects of reversal and turn frequency, amplitude, and directionality. SMD motor neurons help encode the steep amplitude of omega turns, RIV motor neurons specify the ventral bias of turns that follow a reversal, and SMB motor neurons set the amplitude of sinusoidal movement. Many of these sensory neurons, interneurons, and motor neurons are also implicated in chemotaxis and thermotaxis. Thus, this circuit may represent a common substrate for multiple navigation behaviors.

Animals↗

PubMed2003

Influence of parental deprivation on the behavioral development in Octodon degus: modulation by maternal vocalizations.

Repeated separation from the family during very early stages of life is a stressful emotional experience which induces a variety of neuronal and synaptic changes in limbic cortical areas that may be related to behavioral alterations. First, we investigated whether repeated parental separation and handling, without separation from the family, leads to altered spontaneous exploratory behavior in a novel environment (open field test) in 8-day-old Octodon degus. Second, we tested whether the parentally deprived and handled animals display different stimulus-evoked exploratory behaviors in a modified open field version, in which a positive emotional stimulus, the maternal call, was presented. In the open field test a significant influence of previous emotional experience was found for the parameters of running, rearing, and vocalization. Parentally deprived degus displayed increased horizontal (running) and vertical (rearing) motoric activities, but decreased vocalization, compared to normal and handled controls. The presentation of maternal vocalizations significantly modified running, vocalization, and grooming activities, which in the case of running activity was dependent on previous emotional experience. Both deprivation-induced locomotor hyperactivity together with the reduced behavioral response towards a familiar acoustic emotional signal are similar to behavioral disturbances observed in human attachment disorders.

Animals↗

PubMed2004

Role of glutamate ionotropic receptors in the dorsomedial hypothalamic nucleus on anxiety and locomotor behavior.

The medial hypothalamus is proposed to play an important role in the modulation of defensive responses. Administration of a NMDA receptor antagonist (AP7) into the dorsomedial hypothalamic nucleus (DMH) of rats reduced exploratory behavior in the open field and elevated plus-maze (EPM), but failed to produce anxiolytic effects in the latter test. The objectives of the present work were to test the hypotheses that (i) AP7 injections into the DMH would also fail to induce anxiolytic effects in another model of anxiety, the Vogel's punished licking test; (ii) injection into the DMH of other glutamate ionotropic antagonists would also decreased exploratory behavior; and (iii) the decrease in exploratory activity found after AP7 administration into the DMH does not involve any gross locomotor impairment. Male Wistar rats (n=5-16/group) with cannulas aimed at the DMH were submitted to the following behavioral tests: EPM, Vogel, catalepsy and rota-rod. Diazepam (3 mg/kg) and haloperidol (2.5 mg/kg) were used as positive controls in the Vogel, rota-rod and catalepsy tests. AP7 failed to modify the number of punished licks in the Vogel test. It also did not induce any change on the rota-rod and catalepsy tests. Diazepam increased the number of punished licks and reduced the latency to fall in the rota-rod. Both 7-chlorokynurenic acid (4-8 nmol), an antagonist of the glycine competitive site in the NMDA receptor and 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo-[f]-quinoxaline-7-sulphonamide (NBQX, 1-10 nmol), a non-NMDA receptor antagonist, decreased the total distance moved in the EPM. The former compound also decreased open arm exploration at the dose of 4 nmol. The results suggest that the antagonism of ionotropic glutamate receptors in the DMH does not induce anxiolytic effects in the EPM or Vogel tests, but decreases exploratory behavior in a new environment.

2-Amino-5-phosphonovalerate↗

PubMed2000

Effects of L-thyrosyl - L-arginine (kyotorphin) on the behavior of rats and goldfish.

The effects of kyotorphin (KTP), a dipeptide (L-Tyr-L-Arg), on the level of sensory attention to stimuli of different modalities in rats and the exploratory behavior in goldfish were investigated. In both cases KTP was found to suppress the exploratory activity. When 5-HTP, a precursor of serotonin synthesis, is activated the inhibitory effects of KTP increased. It is assumed that the regulatory effect of KTP on the exploratory behavior of animals is mediated by the monoaminergic (neurotransmitting) brain systems, as distinct from its analgetic effects, which are mediated by the opioid brain systems.

5-Hydroxytryptophan↗