Amount Of Locomotion Research Articles

Variations in infants' physical and social environments shape spontaneous locomotion.

Independent locomotion is associated with a range of positive developmental outcomes, but unlike cognitive, linguistic, and social skills, acquiring motor skills requires infants to generate their own input for learning. We tested factors that shape infants' spontaneous locomotion by observing forty 12- to 22-month-olds (19 girls, 21 boys) during free play. Infants were recruited from the New York City area, and caregivers reported that 25 infants were White, six were Asian, four were Black, and five had multiple races; four were Hispanic or Latino. All infants played in four conditions: two environmental conditions (gross-motor toys, fine-motor toys) crossed with two social conditions (alone, together with a caregiver). Infants moved more in the gross-motor toy conditions than in the fine-motor toy conditions. However, the effect of playing with a caregiver differed by toy condition. In the gross-motor toy conditions, playing with a caregiver did not affect how much infants moved, but in the fine-motor toy conditions, playing with a caregiver further depressed infant locomotion. Infants with more walking experience moved more with gross-motor toys but not with fine-motor toys. Differences in the amount of locomotion between conditions were related to how infants used toys and the interactions between infants and caregivers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Neural correlates of multidimensional motor outputs in an excitatory parafascicular-zona incerta circuit

The parafascicular nucleus (Pf) in medial thalamus is interconnected with prefrontal cortex and basal ganglia. Though much research has determined its importance in cognitive regulation of behaviour, its projections to regions in subthalamus remain less known. Such connections include those to zona incerta (ZI), located immediately dorsal to subthalamic nuclei (STN) regulating motor output, and whose role in a motor context is only beginning to be investigated. We thus examined circuits from parafascicular (Pf) thalamus to ZI, and its activity during locomotion and spontaneous behaviours in mice. We found that a distinct group of CaMKIIα-positive excitatory parafascicular neurons, separated from VGLUT2-positive excitatory neurons, project widely into ZI, more than adjacent STN. Our results from fibre photometry and decoding with general linear model (GLM) indicate that PF-ZI pathways do not specifically correlate with amount of locomotion or movement velocity, but instead show more specified activity during relative directional changes of movements observed in turning, sniffing behaviours. These results hint at the PF-ZI pathway having a distinct role in directing action specificity and have implications for subcortical bases in dimensional control of behaviours.

Cognitive training improves the disturbed behavioral architecture of schizophrenia-like rats, “Wisket”

Translational schizophrenia research depends on the relevance of animal models supported by reliable tests. Human data suggest that the intensive cognitive training in schizophrenia improves the memory impairments and decreases the chance of acute psychiatric remission. Here we examined the effects of a 10-day long training session in the behavioral architecture of a new schizophrenia-like rat substrain (Wisket) in a narrow square corridor with food rewards (AMBITUS). The instrument was designed to model the natural environment of rats and enable the simultaneous recording of multiple behavioral parameters. For the compact visualization of differences between the Wisket and control animals in several parameters (behavioromics), color-coded grid plots were applied. The Wisket animals exhibited an altered pattern and/or amount of locomotion, exploratory and food collecting activity at the first few days, revealing impaired motivation, attention, anxiety and learning ability (face validity). Most of the parameters normalized with training, except for the decreased exploratory activity. This resembles the effects of cognitive behavioral therapy in human schizophrenics providing a significant support for the predictive validity of this substrain as an animal model of schizophrenia. This study also highlights the importance of behavior tests that investigate the egocentric learning ability during reward-based tasks.

B43 Huntington's Disease And Circadian Rhythms: What Can Flies Teach Us?

<h3>Background</h3> Circadian rhythms are daily rhythms that control every aspect of our behaviour and physiology in a 24 h fashion. They are common to nearly all living organisms from cyanobacteria to plants and from flies to humans. The underlying molecular mechanisms that control circadian rhythms are well understood and flies are an excellent model to study them as their clock is very similar to ours. Additionally we have high-throughput techniques to analyse the fly’s locomotor activity rhythms, which are equivalent to our sleep/wake cycles. Circadian rhythms are also very sensitive physiological markers of wellbeing and can be easily disturbed by life style changes such as inter continental travel or shift work. Circadian problems can also be the direct or indirect result of brain pathologies as in the case with Huntington’s disease (HD). <h3>Aims</h3> We are characterising a new fly model of HD that is inducible, tuneable and cell type specific. Our aim is to understand early cellular and physiological processes that lead to neuronal dysfunction by using the circadian clock as a readout. Our work may shed light on several under explored areas. For instance: Is HD pathology directly caused by progressive accumulation of mutated huntingtin (HTT) protein over time or by the ageing cell not being able to cope with the mutant protein? Can we reverse HD pathology by turning off the mutated gene? If so, when is the critical point of no return? <h3>Methods</h3> Using the molecular toolkit available for flies, we can over-express mutant human HTT protein in the brain targeting the clock neurons. We can then analyse rhythms of locomotor activity, looking for anomalies in period, phase or amount of locomotion. Turning the mutant HTT gene on or off throughout the life span of the fly we can probe the effects of ageing on rhythmic phenotypes. <h3>Results</h3> Here we show that over expression of mutant human HTT in clock neurons causes arrhythmic behaviour in flies and that this effect is modulated by ageing. <h3>Conclusions</h3> Using circadian rhythms as a tool and fruit flies as a model we have a powerful experimental system to study the pathology caused by the mutated HD protein. In the future, we will focus on the cellular mechanisms leading to neuronal dysfunction/ neurodegeneration in HD and define the critical point in the progression of the disease before which intervention should be made.

Behavioural and neuronal activation after microinjections of AMPA and NMDA into the perifornical lateral hypothalamus in rats

The perifornical lateral hypothalamic area (PeFLH), which houses orexin/hypocretin (OX) neurons, is thought to play an important role in arousal, feeding, and locomotor activity. The present study examined behavioural effects of activating PeFLH neurons with microinjections of ionotropic glutamate receptor agonists. Three separate unilateral microinjections of either (1) AMPA (1 and 2 mM in 0.1 μL artificial cerebrospinal fluid, ACSF) and ACSF, or (2) NMDA (1 and 10 mM in 0.1 μL ACSF), and ACSF were made into the PeFLH of adult male rats. Following each injection, the rats were placed into an open field for behavioural scoring for 45 min. Rats were perfused after the third injection for immunohistochemistry for c-Fos and OX to assess the level of activation of OX neurons. Behavioural analyses showed that, as compared to ACSF conditions, AMPA injections produced a dose-dependent increase in locomotion and rearing that persisted throughout the 45 min recording period, and an increase in drinking. Injection of NMDA at 10 mM, but not 1 mM, induced a transient increase in locomotion and an increase in feeding. Histological analyses showed that while both agonists increased the number of neurons immunoreactive for c-Fos in the PeFLH, only AMPA increased the number of neurons immunoreactive for both c-Fos and OX. There were positive correlations between the number of c-Fos/OX-immunoreactive neurons and the amounts of locomotion, rearing, and drinking. These results support the role of ionotropic glutamate receptors on OX and other neurons in the PeFLH in the regulation of locomotor and ingestive behaviours.

The ontogeny of anxiety‐like behavior in rats from adolescence to adulthood

In human beings, susceptibility to anxiety disorders can be relatively high during adolescence. Understanding the ontogeny of anxiety-like behavior in laboratory rodents has implications for developing anxiolytic drugs that are suitable for this age group. Given the dearth of information about adolescent rodents, this study examined the response of both male and female adolescent, late adolescent, young adult, and older adult rats to three tests of anxiety-like behavior: the emergence test (ET), open field (OF), and elevated plus-maze (EPM). The results showed that adolescent rats exhibited a higher anxiety-like response than adults on each test; the amount of locomotion in the OF and percentage of time spent on the open arms of the EPM increased across the age groups, while older adult rats made the fewest start box re-entries in the ET. These results support the hypothesis that adolescent rats have a more pronounced response to stressors than do adults. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 731–739, 2010.

Reproducibility and variance of a stimulation-induced hemodynamic response in barrel cortex of awake behaving mice

The present work evaluated the reproducibility and variance of the cerebral blood flow (CBF) response to natural whisker stimulation in the barrel cortex of awake behaving mice. The animal was placed on an air float ball that allowed the animal to walk, while the head of the animal was fixed in a custom-made stereotactic apparatus. Dynamic CBF changes in the barrel cortex and animal locomotion were simultaneously monitored with laser–Doppler flowmetry (LDF) and an optical motion sensor that detected the rotation distance of the ball, respectively. Whisker stimulation-induced CBF measured under daytime and nighttime conditions showed consistent responses (24% and 23% of the pre-stimulus baseline, respectively), whereas the amount of locomotion was 1.4 times higher during nighttime relative to daytime. Repeated longitudinal experiments over 7 days showed a reproducible, evoked CBF (13–26% relative to the baseline among 7 animals). The mean of the variance coefficient (i.e., standard deviation divided by mean) across multiple days was 0.11 and 0.75 for evoked CBF and locomotion, respectively. These results showed reproducible and reliable measurements of longitudinal CBF response in behaving mice regardless of day-to-day variations in locomotion. Furthermore, we confirmed that the CBF response to whisker stimulation was well localized and reproducible, measured with laser speckle imaging under awake condition. The results further show the capability of long-term hemodynamic imaging in normal and disease-model mice, which is of particular importance for understanding the longitudinal changes and plasticity of neurovascular coupling and behavioral performances such as during growth, development and aging.

マウスの社会的接触場面における体表面温度の変化

We investigated physiological and behavioral characteristics of socially stressed animals in a resident-intruder paradigm. ICR male mice (resident, n = 14) were exposed individually to a novel male conspecific (intruder, n = 14) in their homecage for 30 min. Along with behavioral analyses, the skin temperatures of both the resident and the intruder were measured simultaneously using a multipoint radiation thermometer. There were no significant differences between the resident and intruder in the amount of locomotion, flight and aggressive behaviors. The mean skin temperature of the residents during the interaction was higher than before the interaction. In addition, the skin temperatures of the intruders were consistently higher than the residents. The results suggest that social stress causes elevation in skin temperature as well as stress-induced hyperthermia in core temperature. Moreover, infrared radiation thermometers may provide an alternative means of measuring physiological parameters of two (or more) subjects simultaneously in the study of animal social behavior.

Social reinstatement responses of meat-type chickens to familiar and unfamiliar conspecifics after exposure to an acute stressor

Runway tests are considered indicative of underlying sociality in birds and their ability to make social discriminations. We evaluated whether experience of a prior stressor alters the subsequent affiliation responses of 9 or 10-day-old chicks simultaneously exposed to familiar (cagemates) and unfamiliar conspecifics placed in goal boxes at opposite ends of a runway. Birds were housed in groups of eight in home cages. Half of the birds in each home cage were used as either familiar or unfamiliar social stimuli in the goal boxes. The other half of the birds were randomly assigned either to a control (CON; n = 51) group that remained undisturbed until testing or to a stress-treatment (STR; n = 52) group that was exposed to a 5-min restraint stressor, returned to its home cage and then tested 1 h later. Birds were individually tested in the runway for 5 min and the behaviours video-recorded. During revision of tapes, the projected floor image of the runway was divided into squares and zones. The stressor decreased ( P < 0.01) the time spent in close proximity (close zone; CZ) to conspecifics regardless of the familiarity of the stimulus birds. Regardless of treatment, test chicks showed shorter latencies to enter ( P < 0.05) and spent longer time ( P < 0.02) in the familiar than in the unfamiliar CZ suggesting that young chicks can discriminate between familiar and unfamiliar conspecifics encountered in novel surroundings. While in close proximity to familiar conspecifics, STR birds showed a reduced ( P < 0.05) number of squares entered compared to CONs. This reduced locomotor activity was not accompanied by an increased activity in other zones of the runway. At the end of the trial, both CON and STR birds showed a reduced ( P < 0.05) locomotor activity in the unfamiliar CZ and an increased ( P < 0.05) activity in the central zone of the runway. Interestingly, no differences were detected between CON and STR birds in the total number of squares entered during the trial. These results suggest that prior stressor exposure did not affect the overall amount of locomotion but altered the spatial distribution of it. Collectively, our findings suggest that exposure to an acute stressor event subsequently affects chicks’ affiliation responses in runway tests. The way a bird will react depends on the identity (familiar or unfamiliar) of the conspecifics in its close environment.

Involvement of the laterodorsal tegmental nucleus in the locomotor response to repeated nicotine administration

The locomotor altering properties of nicotine depend on activation of nicotinic acetylcholine receptors in the ventral tegmental area (VTA). The laterodorsal tegmental nucleus (LDTg) provides a significant proportion of the cholinergic innervation of the VTA. We tested the hypothesis that the locomotor effects of nicotine depend on the functional integrity of the LDTg. The spontaneous locomotor activity of LDTg and sham-lesioned control rats was measured over seven sessions, after which we examined the effects of repeated injections of nicotine in a day on–day off design, giving injections of saline on the nicotine-off days. Spontaneous locomotor activity was significantly lower in LDTg lesioned compared to control rats. LDTg lesions also blunted the effects of nicotine: control rats showed an initial locomotor depression after nicotine, but on repeated testing showed a progressive increase in the amount of locomotion in response to drug challenge. LDTg lesioned rats showed no differences in responding to nicotine compared to saline. These data show that the functional integrity of the LDTg is required in order to show normal locomotor response to nicotine. One explanation for this is that loss of the LDTg affects synaptic activity in the VTA.

Sensitivity to cocaine and amphetamine among mice selectively bred for differential cocaine sensitivity.

Selective breeding of mice for differences in response to a drug offers a powerful means for testing hypotheses regarding underlying mechanisms and relationships between drug-induced behaviors. Starting from a heterogeneous stock of mice, we have selectively bred lines of mice for extreme differences in their locomotor response to 10 mg/kg cocaine HCl. Selection pressure has been maintained for 12 generations and has resulted in two cocaine sensitive (CAHI) and two cocaine insensitive (CALO) lines. Across the generations of selection, the CAHI lines showed progressively greater amounts of cocaine-induced locomotion, with mice from the S12 generation traveling over 21,000 cm/30 min. following 10 mg/kg cocaine. The CALO lines, in contrast, did not substantially diverge from control values until the S8 generation. By generation 12, however, the LO lines traveled no further following 10 mg/kg cocaine (7000 cm/30 min), than they did following an initial saline injection. Cocaine and amphetamine dose-response analyses were conducted on drug-naive mice from the tenth generation. The CAHI lines were extremely sensitive to the locomotor activating effects of all doses of cocaine, displaying from 2- to 6-fold greater amounts of cocaine-induced locomotion than the CALO lines. The CALO lines, in contrast, were completely insensitive to the psychomotor stimulant effects of cocaine. The CAHI lines were also more sensitive to the locomotor activating effects of amphetamine. Both lines showed dose-dependent amphetamine-induced locomotion that peaked at 3 mg/kg. However, at all doses, the CAHI lines showed a 2- to 4-fold greater amount of locomotion than CALO lines. Thus, the sensitivity to cocaine developed through selection using a single dose of cocaine has generalized to a range of doses of cocaine and to at least one other psychostimulant.

Effects of blindness on play fighting in golden hamster infants

The effects of bilateral optic enucleation on play fighting in golden hamster infants were studied. The behaviors of blind-blind (BB), blind-intact (BI) and intact-intact (II) dyads were recorded from the 30th to the 36th day of age. It has been noted that the differences in physical contact, play fighting and grooming time, as well as in the percentage of time spent in play fighting, the amount of locomotion and other activities of BB, BI and II were small and statistically insignificant. The mean number of active and passive pinning in all groups was equivalent and the alternation of active and passive pinning, or vice versa, was around 50%, showing that posture during play fighting is not an indicator of dominance. It has been concluded that vision is not important for either the initiation or the modulation of play fighting in golden hamsters.

A genetic analysis of locomotor activity in Drosophila melanogaster

The locomotor activity of flies observed as isolated individuals in an “open field” observation chamber contains two components—the amount and speed of movement. These are distinct behavioural phenotypes. The reactivity of flies to handling disturbance is reflected chiefly by changes in the speed rather than in the amount of locomotion, but there are significant differences in the overall pattern of expression of reactivity between males and females. The amount and speed of locomotion are under independent genetic control, but genes affecting movement in the “open field” may also have effects on the locomotor activity of virgin females when they are courted. Variation in the locomotor activity of females has little effect on the amount of wing vibration which males direct at them, but significantly affects the amount of contact stimulation by licking which they receive.

Imipramine normalizes naturally-occurring and drug-induced differences in the exploratory activity of rats.

1 Exploratory activity of female hooded rats was measured in a Y maze on two occasions, 1 week apart. Locomotion (maze arm entries), rearing, and head-dipping into pots were scored for 5 min at each trial. 2 In control rats, differences between individuals in the amount of locomotion and rearing were consistent, as shown by significant test-retest correlations (r = +0.55, and +0.83 respectively). There was no correlation between head-dipping scores obtained in the two tests. 3 Imipramine (Imip) pretreatment before the second trial (10 mg/kg i.p on the 3 preceding days, and 2.5 mg/kg 1 h before) abolished these correlations. The scatter of the scores about the mean was also reduced by Imip, but there was no significant change in mean scores. Thus Imip appeared to have a 'normalizing' effect on locomotion and rears: after pretreatment, scores tended to be more uniform, and no longer reflected naturally-occurring individual differences. 4 Imip abolished the changes in exploratory activity produced by drugs which alter brain 5-hydroxytryptamine metabolism: p-chlorophenylalanine (100 mg/kg 24 h before testing) increased and DL-5-hydroxytryptophan (12.5 mg/kg 1 h before testing) decreased the fall in activity over the trial in saline-treated rats but not that in Imip-treated rats. In this case, Imip also produced an overall reduction in activity scores. 5 The normalizing effects of Imip on rat behaviour may be analogous to its therapeutic effects in human depressive disorders.

The effect of dopamine and noradrenaline blockade on amphetamine-induced behaviour in the marmoset

Acute administration of 4 mg/kg d-amphetamine in the marmoset results in a large increase in small head movements (checking), an almost total suppression of purposeful activities and social interaction, but little change in the amount of locomotion. Checking behaviour is blocked in a dose dependent manner by 0.03--0.18 mg/kg haloperidol but not by propranolol, aceperone or diazepam, suggesting dopaminergic mediation of this behaviour. The loss of activities and social interaction after amphetamine is not antagonized by any of the drugs used in this study. Locomotion is decreased by haloperidol, propranolol and diazepam in amphetamine treated animals and by haloperidol and aceperone in normal animals.

Free and forced exploration in rats as a function of between- vs within-Ss design

Wistar rats were given 16 open-field tests under (a) free exploration (Ss could withdraw from the field into a small dark box), (b) forced exploration, or (c) alternating free and forced exploration. Amount of locomotion and the tendency to leave the peripheral wall were initially suppressed under free exploration but recovered over tests. The tendency to rear in the field remained suppressed under free exploration over all tests. It was suggested that fear functions to inhibit locomotion under forced exploration and functions to motivate and reward escape into the small box under free exploration. As fear habituates, open-field locomotion increases.

Behavioral thermoregulation by the white rat at high ambient temperatures.

AbstractAt ambient temperatures greater than 40°C, rats must spread salvia on themselves to prevent lethal hyperthermia. This study examined the effect of other behavioral parameters on a rat's ability to thermoregulate. The animals were exposed to 42°C in a cylindrical wire cage; records of time spent saliva spreading and moving about the cage were made; and body temperatures were measured with thermocouples implanted in the animals' abdominal cavities. Very little time spent saliva spreading was necessary for an animal to become thoroughly wetted on its ventral surface. Once wetted, an animal's thermoregulatory ability depended on its amount of locomotion. Animals which spent a considerable amount of time climbing about the cage were unable to stabilize their body temperatures and suffered increasing hyperthermia. Those which had low levels of locomotion were able to hold a constant body temperature for an hour or more. Several of the animals were given seven successive exposures to 40°C, followed by a second exposure to 42°C. Most of these animals showed greatly improved thermoregulatory abilities in the second exposure at 42°C as compared with the first, and this improvement was associated with markedly decreased locomotion. Several animals showed increased saliva spreading, but this change was not well correlated with improved thermoregulatory ability. It was concluded that low levels of locomotion are essential for evaporative cooling by saliva spreading to be adequate, and that repeated exposures to heat can modify an animal's behavior to the type associated with prolonged thermoregulation.

Extinction of fear. I. Effects of amylobarbitone and dexamphetamine given separately and in combination on fear and exploratory behaviour in rats.

Passive avoidance by rats of an environment previously associated with inescapable electric shocks, was taken as an index of the level of fear on repeated, unpunished tests. Locomotor and non-locomotor exploratory activity was also recorded during these tests. Although amylobarbitone diminished fear it did not accelerate its extinction; the amounts of locomotion were increased in both shocked and unshocked rats and tolerance did not develop to these effects of amylobarbitone.