Reduced Walking Activity Research Articles

Neuroregulation of foraging behavior mediated by the olfactory co-receptor Orco in termites

Olfaction is critical for survival because it allows animals to look for food and detect pheromonal cues. Neuropeptides modulate olfaction and behaviors in insects. While how the neuroregulation of olfactory recognition affects foraging behavior in termites is still unclear. Here, we analyzed the change after silencing the olfactory co-receptor gene (Orco) and the neuropeptide Y gene (NPY), and then investigated the impact of olfactory recognition on foraging behavior in Odontotermes formosanus under different predation pressures. The knockdown of Orco resulted in the reduced Orco protein expression in antennae and the decreased EAG response to trail pheromones. In addition, NPY silencing led to the damaged ability of olfactory response through downregulating Orco expression. Both dsOrco- and dsNPY-injected worker termites showed significantly reduced walking activity and foraging success. Additionally, we found that 0.1 pg/cm trail pheromone and nestmate soldiers could provide social buffering to relieve the adverse effect of predator ants on foraging behavior in worker termites with the normal ability of olfactory recognition. Our orthogonal experiments further verified that Orco/NPY genes are essential in manipulating termite olfactory recognition during foraging under different predation pressures, suggesting that the neuroregulation of olfactory recognition plays a crucial role in regulating termite foraging behavior.

IDH knockdown alters foraging behavior in the termite Odontotermes formosanus in different social contexts.

Foraging, as an energy-consuming behavior, is very important for colony survival in termites. How energy metabolism related to glucose decomposition and adenosine triphosphate (ATP) production influences foraging behavior in termites is still unclear. Here, we analyzed the change in energy metabolism in the whole organism and brain after silencing the key metabolic gene isocitrate dehydrogenase (IDH) and then investigated its impact on foraging behavior in the subterranean termite Odontotermes formosanus in different social contexts. The IDH gene exhibited higher expression in the abdomen and head of O. formosanus. The knockdown of IDH resulted in metabolic disorders in the whole organism. The dsIDH-injected workers showed significantly reduced walking activity but increased foraging success. Interestingly, IDH knockdown altered brain energy metabolism, resulting in a decline in ATP levels and an increase in IDH activity. Additionally, the social context affected brain energy metabolism and, thus, altered foraging behavior in O. formosanus. We found that the presence of predator ants increased the negative influence on the foraging behavior of dsIDH-injected workers, including a decrease in foraging success. However, an increase in the number of nestmate soldiers could provide social buffering to relieve the adverse effect of predator ants on worker foraging behavior. Our orthogonal experiments further verified that the role of the IDH gene as an inherent factor was dominant in manipulating termite foraging behavior compared with external social contexts, suggesting that energy metabolism, especially brain energy metabolism, plays a crucial role in regulating termite foraging behavior.

Anti-instinctive Learning Behavior Revealed by Locomotion-Triggered Mild Heat Stress in Drosophila.

Anti-instinctive learning, an ability to modify an animal's innate behaviors in ways that go against one's innate tendency, can confer great evolutionary advantages to animals and enable them to better adapt to the changing environment. Yet, our understanding of anti-instinctive learning and its underlying mechanisms is still limited. In this work, we describe a new anti-instinctive learning behavior of fruit flies. This learning paradigm requires the fruit fly to respond to a recurring, aversive, mild heat stress by modifying its innate locomotion behavior. We found that experiencing movement-triggered mild heat stress repeatedly significantly reduced walking activity in wild type fruit flies, indicating that fruit flies are capable of anti-instinctive learning. We also report that such learning ability is reduced in dopamine 1-like receptor 1 (Dop1R1) null mutant and dopamine 2-like receptor (Dop2R) null mutant flies, suggesting that these two dopamine receptors are involved in mediating anti-instinctive learning in flies.

Behavioral responses of northern crayfish (Faxonius virilis) to conspecific alarm cues and predator cues from smallmouth bass (Micropterus dolomieu)

ABSTRACTWhile the ability for crayfish to detect visual and chemical cues is well documented, relatively few studies have probed the behavioral responses of crayfish to cues from key predators that they encounter in natural environments. Therefore, we examined how northern crayfish (Faxonius virilis) (Hagen 1870) responded to (1) alarm cues from conspecifics versus chemical cues from smallmouth bass (Micropterus dolomieu) (Lacepéde 1802), (2) varying concentrations of alarm cue from conspecifics, and lastly (3) smallmouth bass visual cues, chemical cues, and a combination of the two. We found that crayfish reduced walking activity in the presence of alarm cues. Chemical cues from smallmouth bass were also capable of eliciting a behavioral response, both alone and when paired with visual cues. Understanding the behavioral mechanisms by which crayfish respond to predatory fish is important to managing freshwater systems in the context of ongoing human- and climate-aided range expansions of both taxa.

Neural substrates of reduced walking activity after supratentorial stroke: A voxel-based lesion symptom mapping study

BackgroundMost stroke patients exhibit low levels of walking activity, a key component of secondary stroke prevention. The predictors of walking activity may be multifactorial and are thus far partially understood. We aimed to study the neuroanatomic correlates of low levels of daily walking activity following hemispheric stroke. MethodsIn this cross-sectional study, 33 community-dwelling stroke survivors (age: 63.9 ± 12.9 years; % female: 36.4%; NIHSS at admission: 3.3 ± 4.0) were prospectively recruited at least 3 months after a first ever, unilateral, supratentorial stroke confirmed by brain magnetic resonance imaging. Walking activity was measured by daily step counts (steps∙day−1), recorded using an Actigraph GT3x+ triaxial accelerometer over 7 consecutive days. Voxel-based lesion-symptom mapping was performed to identify brain areas associated with walking activity following stroke. ResultsParticipants presented 4491.9 ± 2473.7 steps∙day−1. Lower levels of walking activity were related to lesions of the posterior part of the putamen, of the posterior limb of the internal capsule and of the anterior part of the corona radiata. No cortical region was associated with walking activity. ConclusionsOur preliminary results identify subcortical neuroanatomical correlates for reduced walking activity following stroke. If confirmed, these results could serve as a rationale for the development of targeted rehabilitative strategy to improve mobility after stroke.

Which impairments, activity limitations and personal factors at hospital discharge predict walking activity across the first 6 months poststroke?

Purpose: To determine which impairments, activity limitations and personal factors at hospital discharge poststroke predict volume, frequency, and intensity of walking activity 1, 3, and 6 months later.Materials and Methods: Prospective longitudinal observational study. Thirty-six people with stroke (71 SD 14 years, 69% male) were recruited at hospital discharge and predictors including fatigue, mood, executive function, walking speed, walking endurance, age, prestroke activity, self-efficacy, and perceived stroke recovery and health were collected. At 1, 3, and 6 months follow-up, participants wore an ActivPAL™ accelerometer to collect measures of walking activity.Results: At 1 month, walking endurance predicted all walking activity (R2 > 0.29, p < 0.01). At 3 months, walking endurance and prestroke activity predicted activity volume and intensity (R2 = 0.46–0.61, p < 0.001), and prestroke activity predicted activity frequency (R2 = 0.31, p = 0.004). At 6 months, age-predicted activity volume and frequency (R2 = 0.34–0.35, p < 0.003), while prestroke activity, discharge walking endurance, and executive function together predicted activity intensity (R2 = 0.79, p < 0.001).Conclusion: Walking endurance contributes to walking activity outcomes across the first 6 months following hospital discharge poststroke. After 1 month of discharge, factors other than poststroke changes also contribute to activity outcomes, and should be considered when targeting poststroke physical activity.Implications for rehabilitationWalking endurance should be addressed during stroke rehabilitation as higher scores are linked to more walking activity in the first month after discharge.Prestroke factors such as low prestroke activity levels and older age predict reduced walking activity after stroke, so approaches to address barriers these factors may pose are needed in people with stroke.Physical activity interventions should be tailored to the individual, their environment, and context, and take into consideration prestroke factors.

Locomotor behavior of Sitophilus zeamais populations under sublethal ozone exposure

Insects exhibit diverse behavioral responses under insecticide exposure. However, such responses have been neglected in toxicological studies. The purpose of this work was to evaluate the influence of sublethal concentrations of ozone on the locomotor behavior of populations of the maize weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Additionally, respiration rate and body mass were also evaluated. The behavioral characteristics evaluated were distance traveled, resting time, and walking velocity of males and females, along with flight initiation for non-sexed insects. Ozone concentrations of 0, 30, 40, 50, and 60 ppm were established for the Amambay population and ozone concentrations of 0, 50, 75, 100, 125, and 150 ppm for the Sao Joao population of S. zeamais. The walking activity of the Amambay insect population decreased with increasing ozone concentration. In contrast, the walking activity of the Sao Joao population did not vary with ozone concentration. At least one of the walking characteristics is correlated with the respiration rate and body mass, indicating an association of increased respiration rate and body mass with reduced walking activity. In general, the behavioral response to ozone was population dependent. The reduction in walking activity of the S. zeamais populations under sublethal ozone exposure might limit the insect’s ability to escape its effects. These results implicate in a low risk of resistance evolution in a short term, indicating that ozone is a potential option to control pest insects of stored products.

Exercise training for management of peripheral arterial disease: a systematic review and meta-analysis.

Peripheral arterial disease (PAD), a chronic condition with debilitating clinical sequelae, leads to reduced walking activity and increased mortality risk. We sought to quantify expected benefits elicited via exercise training in people with PAD and aimed to clarify which prescriptions were optimal. We conducted a systematic search (PubMed, CINAHL, Cochrane controlled trials registry; 1966-31 July 2013). We included randomized controlled trials (RCTs) of exercise training versus usual medical care in persons with PAD. Studies were assessed by two reviewers, 41 of 57 (72%) of RCTs met selection criteria. Data extraction sheets were used to record data and two reviewers cross-checked data. Included study authors were asked for missing data. Primary outcome: change in aerobic capacity (peak VO2). Secondary outcomes: ankle-brachial index (ABI), flow-mediated dilatation, 6-minute walk claudication distances (initial and absolute) and graded treadmill (initial and absolute) distances. The primary hypothesis was that peak VO2 would increase with exercise training. Using sub-analyses, we also aimed to clarify what types of exercise prescription would provide patients with most benefit; hypotheses were developed a priori. Exercise training produced significant peak VO2 improvements with mean difference (MD) 0.62 ml·kg(-1)·min(-1) (95% CI 0.47-0.77; p < 0.00001); 6-minute walk initial claudication MD 52.7 m (95% CI 24.7-80.6 m; p = 0.0002); total walking distance MD 34.9 m (95% CI 25.6-44.1 m; p < 0.00001); graded treadmill initial claudication MD 68.8 m (95% CI 54.4-83.2 m; p < 0.00001); absolute claudication distance MD 41.0 m (95% CI 28.8-53.2 m; p < 0.00001)); but not ABI (p = 0.12) or flow mediated dilatation (FMD) (p = 0.96). Sub-analyses of change in peak VO2 after arm cranking showed a MD of 1.91 ml·kg(-1)·min(-1) (95% CI 1.28-2.54, p < 0.00001). Sub-analysis of peak VO2 according to exercise training pain thresholds suggested that no-to-mild pain may be superior (MD 0.79 ml·kg(-1)·min(-1) [95% CI 0.45-1.14, p < 0.00001]) to moderate-to-maximum training pain (MD 0.49 ml·kg(-1)·min(-1) [95% CI 0.31-0.66, p < 0.00001]). Exercise training improves cardio-respiratory fitness, pain-free and total flat-ground walking distances, as well as graded treadmill performance in PAD. Exercise prescriptions for PAD may consider arm cranking as well as lower limb exercise, possibly at short vigorous intensity intervals, but only to a threshold of mild pain.

The Structure of Walking Activity in People After Stroke Compared With Older Adults Without Disability: A Cross-Sectional Study

People with stroke have reduced walking activity. It is not known whether this deficit is due to a reduction in all aspects of walking activity or only in specific areas. Understanding specific walking activity deficits is necessary for the development of interventions that maximize improvements in activity after stroke. The purpose of this study was to examine walking activity in people poststroke compared with older adults without disability. A cross-sectional study was conducted. Fifty-four participants poststroke and 18 older adults without disability wore a step activity monitor for 3 days. The descriptors of walking activity calculated included steps per day (SPD), bouts per day (BPD), steps per bout (SPB), total time walking per day (TTW), percentage of time walking per day (PTW), and frequency of short, medium, and long walking bouts. Individuals classified as household and limited community ambulators (n=29) did not differ on any measure and were grouped (HHA-LCA group) for comparison with unlimited community ambulators (UCA group) (n=22) and with older adults without disability (n=14). The SPD, TTW, PTW, and BPD measurements were greatest in older adults and lowest in the HHA-LCA group. Seventy-two percent to 74% of all walking bouts were short, and this finding did not differ across groups. Walking in all categories (short, medium, and long) was lowest in the HHA-LCA group, greater in the UCA group, and greatest in older adults without disability. Three days of walking activity were captured. The specific descriptors of walking activity presented provide insight into walking deficits after stroke that cannot be ascertained by looking at steps per day alone. The deficits that were revealed could be addressed through appropriate exercise prescription, underscoring the need to analyze the structure of walking activity.

Physical activity and other health-related factors predict health care utilisation in older adults

Health care utilisation (HCU) can be a useful outcome for estimating costs and patient needs. It can also be used as a surrogate parameter for healthy ageing. The aim of this study was to analyse the associations of formerly described and potentially new parameters influencing health care utilisation in older adults in Germany. The ActiFE Ulm (Activity and Function in the Elderly in Ulm) study is a population-based study in 1,506 community dwelling older adults aged 65-90 years in Ulm and surrounding areas in southwestern Germany. Between March 2009 and April 2010 a full geriatric assessment was performed including accelerometer-based average daily walking duration, comorbidity, medication, physical and psychological functioning, health care utilisation, sociodemographic factors etc. The association between above named measures and health care utilisation, represented by the number of drugs, the days in hospital and the number of physician contacts over one year was calculated in multiple regression models. Analysis was conducted among subjects with complete information (n = 1,059, mean age 76 years, 55% male). The average number of drugs was 4.5 and over 95% of participants visited a physician at least once a year while still more than 65% contacted their physician more than twice a year. Reduced physical activity, BMI, self-rated health and/or comorbidity and male sex were the best predictors of health care utilisation in community dwelling older adults when looking at both the number of drugs and the number of physician contacts over 12 months together. With regard to single diseases entities the best predictors of both the number of drugs and the number of physician contacts were asthma, chronic obstructive pulmonary disease (COPD)/chronic bronchitis and chronic neurological diseases (mostly Parkinson's disease). The number of drugs was most strongly associated with coronary heart disease, diabetes, and high blood pressure. Reduced walking activity, self-rated health and/or comorbidity and male sex are the best predictors of health care utilisation as measured by the number of drugs and number of physician contacts over 12 months. Walking activity could be regarded as the most promising modifiable predictor of HCU in older adults.

Phosphine‐induced walking response of the lesser grain borer (Rhyzopertha dominica)

In spite of the intensive worldwide use of phosphine against stored-product insects, its potential sublethal effects on targeted insect species is seldom recognised and may compromise the efficacy of this fumigant, particularly against phosphine-resistant insects. Therefore, the behavioural response of three populations of the lesser grain borer Rhyzopertha dominica (Coleoptera: Bostrichidae) to sublethal phosphine exposure was assessed. Concentration-mortality bioassays with phosphine confirmed the resistance status of the insect populations studied, with levels of phosphine resistance of 40.8-fold and 85.7-fold compared with the susceptible population. Regarding walking behaviour, determined using a digital video-tracking system, the phosphine-resistant populations were less active than the susceptible population. In addition, sublethal phosphine exposure decreased the walking activity of all three populations. Phosphine exposure decreased walking activity. Such reduced walking activity is likely to lower the respiration rate, thereby minimising phosphine uptake. As higher phosphine resistance was also associated with reduced walking activity, phosphine-resistant populations may resist phosphine fumigation even more efficiently on account of this behavioural trait, further aiding their physiological resistance, and should be a matter of concern.

Predictors of Early Stem Loosening after Total Hip Arthroplasty: A Case-Control Study

To evaluate the influence of patient characteristics on stem loosening after cemented or uncemented total hip arthroplasty (THA) using a matched case-control study. METHODS; Consecutive records of 4372 cemented (716 cases and 3656 controls) and 809 uncemented (115 cases and 694 controls) primary THAs between 1981 and 2003 in 30 hospitals in 8 European countries were reviewed. Cases and controls were defined as patients with and without stem loosening, respectively. In cases of bilateral THA, patients were their own controls. Cases and controls were matched for hospital, date of surgery, date of follow-up, stem type, and head size. Patient characteristics such as gender, age, weight, height, body mass index (BMI), diagnosis, presence of previous surgery on the affected hip, and walking restrictions according to the Charnley classification were recorded. Male patients were at higher risk of cemented stem loosening (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.4-2.2). Older patients were at lower risk of cemented stem loosening; the odds decreased by 3% per year older (OR, 0.97; 95% CI, 0.96-0.98). Regarding BMI, the odds of cemented stem loosening increased by 3% for each additional unit of BMI over 25 kg/m² square (OR, 1.03; 95% CI, 1.004-1.05). Patients in Charnley class B had a lower risk of cemented stem loosening (OR, 0.75; 95% CI, 0.61-0.93). Advanced age, female gender, and Charnley class B (as a proxy measure of reduced walking activity) have a protective effect on survival of cemented stems, whereas a higher BMI was a risk factor.