Quantitative Assessment of Stereotyped and Challenged Locomotion after Lesion of the Striatum: A 3D Kinematic Study in Rats

Background

Although the striatum is in position to regulate motor function, the role of the structure in locomotor behaviour is poorly understood. Therefore, a detailed analysis of locomotion- and obstacle avoidance-related parameters was performed after unilateral lesion of the striatum in rats.

Methods and Results

Using the three dimensional motion capture technology, kinematics of walking and clearing obstacles, head and body orientation were analyzed before and up to 60 days after the lesion. Recordings were performed in treadmill running rats with or without obstacles attached to the treadmill belt. The lesion, which was induced by the direct injection of the mitochondrial toxin malonate into the left caudoputamen resulted in the complete destruction of the dorsal striatum. During the first three days following the lesion, rats were unable to run on the treadmill. Thereafter, rats showed normal looking locomotion, yet the contralesional limbs exhibited changes in length and timing parameters, and were overflexed. Moreover, the head of lesioned rats was orientated towards the side of the lesion, and their postural vertical shifted towards the contralesional side. During obstructed running, the contralesional limbs when they were leading the crossing manoeuvre stepped on the obstacle rather than to overcome obstacle without touching it, yet more frequently with the forelimb than the hindlimb. Unsuccessful crossings appeared to be due to a paw placement farther away from the front of the obstacles, and not to an inappropriate limb elevation. Importantly, deficit in locomotor behaviour did not regress over the time.

Conclusion

Our results argue that the striatum of one hemisphere controls kinematics of contralateral limbs during stereotyped locomotion and plays a prominent role in the selection of the right motor program so that these limbs successfully cross over obstacle.     

Relationship between the obstacle height cognition and step movement in the elderly

Background

This study examines the effect of obstacle height cognition (OHC) on single-leg forward step (SFS) and Obstacle-SFS.

Methods

In the SFS test, participants stepped 25 cm forward with one leg and returned it to its original position five times as quickly as possible. The Obstacle-SFS added an obstacle to the above condition in the SFS test. The participants were divided into two groups: tripping group, which tripped over an obstacle in the Obstacle-SFS test; and non-tripping group, which did not trip. Parameters were step time (T), the time it took to step forward (F), and the time it took to return to the original position (R). The OHC was determined by the difference between the elevated leg’s height and the obstacle height (10 cm), which was set at 60 cm in front of the participant.

Results

OHC showed a significant and moderate relationship with all parameters of Obstacle-SFS (OSFS-T, OSFS-F and OSFS-R). The tripping group had significantly larger values in the OHC, OSFS-T and OSFS-F than the non-tripping group.

Conclusions

In conclusion, the differences in obstacle height cognition ability may affect Obstacle-SFS movement.     

Age-related and obstacle height-related differences in movements while stepping over obstacles

Background

This study aims to examine age-related and obstacle height-related differences in movements while stepping over obstacles.

Methods

The participants included 16 elderly and nine young women. Obstacles that were either 5 or 20 cm high were positioned at the center of a 4-m walking path. The participants were instructed to walk along the path as quickly as possible. The participants’ movements were analyzed using a three-dimensional motion analysis system that recorded their movements as they walked and stepped over the obstacles.

Results and conclusions

Seven joint angles and the distances between the ground and six markers were examined in the initial contact and swing instants of the leading and trailing limbs. In the initial contact instant, the elderly women prepared for stepping with a lower toe height than the young women when stepping over the 20-cm obstacle. Trunk rotation was greater in the young women than in the elderly women. In the swing instant, the elderly women showed greater ankle dorsiflexion and hip adduction angles for the leading limb when stepping over the 20-cm obstacle. They moved the trailing limb with increased ankle dorsiflexion, knee flexion, hip flexion, and foot inversion to ensure that they did not touch the obstacle as they stepped over it. These movement patterns are characteristic of elderly individuals who cannot easily lift their lower limbs because of decreased lower-limb strength.     

Perceptual Adaptation to the Correction of Natural Astigmatism

Background

The visual system adjusts to changes in the environment, as well as to changes within the observer, adapting continuously to maintain a match between visual coding and visual environment. We evaluated whether the perception of oriented blur is biased by the native astigmatism, and studied the time course of the after-effects following spectacle correction of astigmatism in habitually non-corrected astigmats.

Methods and Findings

We tested potential shifts of the perceptual judgments of blur orientation in 21 subjects. The psychophysical test consisted on a single interval orientation identification task in order to measure the perceived isotropic point (astigmatism level for which the image did not appear oriented to the subject) from images artificially blurred with constant blur strength (B = 1.5 D), while modifying the orientation of the blur according to the axis of natural astigmatism of the subjects. Measurements were performed after neutral (gray field) adaptation on naked eyes under full correction of low and high order aberrations. Longitudinal measurements (up to 6 months) were performed in three groups of subjects: non-astigmats and corrected and uncorrected astigmats. Uncorrected astigmats were provided with proper astigmatic correction immediately after the first session. Non-astigmats did not show significant bias in their perceived neutral point, while in astigmatic subjects the perceived neutral point was significantly biased, typically towards their axis of natural astigmatism. Previously uncorrected astigmats shifted significantly their perceived neutral point towards more isotropic images shortly (2 hours) after astigmatic correction wear, and, once stabilized, remained constant after 6 months. The shift of the perceived neutral point after correction of astigmatism was highly correlated with the amount of natural astigmatism.

Conclusions

Non-corrected astigmats appear to be naturally adapted to their astigmatism, and astigmatic correction significantly changes their perception of their neutral point, even after a brief period of adaptation.     

Tactile Motion Adaptation Reduces Perceived Speed but Shows No Evidence of Direction Sensitivity

Introduction

While the directionality of tactile motion processing has been studied extensively, tactile speed processing and its relationship to direction is little-researched and poorly understood. We investigated this relationship in humans using the ‘tactile speed aftereffect’ (tSAE), in which the speed of motion appears slower following prolonged exposure to a moving surface.

Method

We used psychophysical methods to test whether the tSAE is direction sensitive. After adapting to a ridged moving surface with one hand, participants compared the speed of test stimuli on the adapted and unadapted hands. We varied the direction of the adapting stimulus relative to the test stimulus.

Results

Perceived speed of the surface moving at 81 mms⁻¹ was reduced by about 30% regardless of the direction of the adapting stimulus (when adapted in the same direction, Mean reduction = 23 mms⁻¹, SD = 11; with opposite direction, Mean reduction = 26 mms⁻¹, SD = 9). In addition to a large reduction in perceived speed due to adaptation, we also report that this effect is not direction sensitive.

Conclusions

Tactile motion is susceptible to speed adaptation. This result complements previous reports of reliable direction aftereffects when using a dynamic test stimulus as together they describe how perception of a moving stimulus in touch depends on the immediate history of stimulation. Given that the tSAE is not direction sensitive, we argue that peripheral adaptation does not explain it, because primary afferents are direction sensitive with friction-creating stimuli like ours (thus motion in their preferred direction should result in greater adaptation, and if perceived speed were critically dependent on these afferents’ response intensity, the tSAE should be direction sensitive). The adaptation that reduces perceived speed therefore seems to be of central origin.     

Does My Step Look Big In This? A Visual Illusion Leads To Safer Stepping Behaviour

Background

Tripping is a common factor in falls and a typical safety strategy to avoid tripping on steps or stairs is to increase foot clearance over the step edge. In the present study we asked whether the perceived height of a step could be increased using a visual illusion and whether this would lead to the adoption of a safer stepping strategy, in terms of greater foot clearance over the step edge. The study also addressed the controversial question of whether motor actions are dissociated from visual perception.

Methodology/Principal Findings

21 young, healthy subjects perceived the step to be higher in a configuration of the horizontal-vertical illusion compared to a reverse configuration (p = 0.01). During a simple stepping task, maximum toe elevation changed by an amount corresponding to the size of the visual illusion (p<0.001). Linear regression analyses showed highly significant associations between perceived step height and maximum toe elevation for all conditions.

Conclusions/Significance

The perceived height of a step can be manipulated using a simple visual illusion, leading to the adoption of a safer stepping strategy in terms of greater foot clearance over a step edge. In addition, the strong link found between perception of a visual illusion and visuomotor action provides additional support to the view that the original, controversial proposal by Goodale and Milner (1992) of two separate and distinct visual streams for perception and visuomotor action should be re-evaluated.     

Prolonged visual experience in adulthood modulates holistic face perception

Background

Using the well-known composite illusion as a marker of the holistic perception of faces, we tested how prolonged visual experience with a specific population of faces (4- to 6-year-old children) modulates the face perception system in adulthood.

Methodology/Principal Findings

We report a face composite effect that is larger for adult than children faces in a group of adults without experience with children faces (“children-face novices”), while it is of equal magnitude for adults and children faces in a population of preschool teachers (“children-face experts”). When considering preschool teachers only, we observed a significant correlation between the number of years of experience with children faces and the differential face composite effect between children and adults faces. Participants with at least 10 years of qualitative experience with children faces had a larger composite face effect for children than adult faces.

Conclusions/Significance

Overall, these observations indicate that even in adulthood face processes can be reshaped qualitatively, presumably to facilitate efficient processing of the differential morphological features of the frequently encountered population of faces.     

Distortions of subjective time perception within and across senses

Background

The ability to estimate the passage of time is of fundamental importance for perceptual and cognitive processes. One experience of time is the perception of duration, which is not isomorphic to physical duration and can be distorted by a number of factors. Yet, the critical features generating these perceptual shifts in subjective duration are not understood.

Methodology/Findings

We used prospective duration judgments within and across sensory modalities to examine the effect of stimulus predictability and feature change on the perception of duration. First, we found robust distortions of perceived duration in auditory, visual and auditory-visual presentations despite the predictability of the feature changes in the stimuli. For example, a looming disc embedded in a series of steady discs led to time dilation, whereas a steady disc embedded in a series of looming discs led to time compression. Second, we addressed whether visual (auditory) inputs could alter the perception of duration of auditory (visual) inputs. When participants were presented with incongruent audio-visual stimuli, the perceived duration of auditory events could be shortened or lengthened by the presence of conflicting visual information; however, the perceived duration of visual events was seldom distorted by the presence of auditory information and was never perceived shorter than their actual durations.

Conclusions/Significance

These results support the existence of multisensory interactions in the perception of duration and, importantly, suggest that vision can modify auditory temporal perception in a pure timing task. Insofar as distortions in subjective duration can neither be accounted for by the unpredictability of an auditory, visual or auditory-visual event, we propose that it is the intrinsic features of the stimulus that critically affect subjective time distortions.     

Perceived discrimination and self-rated health in South Korea: a nationally representative survey

Background

There is mounting evidence that discriminatory experiences can harm health. However, previous research has mainly focused on the health effects of racial discrimination in U.S. or European countries although there is pervasive discrimination by gender, age, education and other factors in Asian countries.

Methods

We analyzed the data from the 7th wave of Korean Labor and Income Panel Study to investigate the association between perceived discriminatory experience and poor self-rated health in South Korea. Perceived discriminatory experiences were measured in eight situations through a modified Experience of Discrimination questionnaire. In each of eight situations, the lifetime prevalence of perceived discriminatory experience was compared between men and women and the main causes of those experiences were identified separately by gender. After adjusting for potential confounders, we examined the association between perceived discriminatory experience and poor self-rated health in each of eight social situations and also checked the association using the number of situations of perceived discriminatory experiences.

Results

For both men and women, education level and age were the main sources of work-related perceived discriminatory experiences. Gender was one of the main causes among women across eight situations and more than 90% of women reported their gender as a main cause of discriminatory experience in getting higher education and at home. Discriminatory experiences in four situations were positively associated with poor self-rated health. The odds ratio for poor self-rated health for those exposed to one, two, three or four or more social situations of perceived discrimination were respectively 1.06 (95% CI : 0.87–1.29), 1.15 (95% CI : 0.96–1.55), 1.59 (95% CI : 1.19–2.14), and 1.78 (95% CI :1.26–2.51).

Conclusion

There is consistent association between perceived discriminatory experience and poor self-rated health across eight social situations in South Korea.     

Weight-Loss Strategies Used by the General Population: How Are They Perceived?

Background

The rising prevalence of obesity and the social pressure for thinness increase the prevalence of dieting. However, little is known about the overall perception of dieting strategies actually used by the general population.

Objectives

Our main objective was to investigate perceptions of weight-loss practices in an observational study in order to identify the most favourable strategy.

Design

Adults from the ongoing Nutrinet-Santé cohort study who had reported engaging in dieting in the three previous years were included in the study. For each diet, detailed information was collected on types of diets, circumstances and perception of the diet, and outcomes. Perceptions were compared across diets using sex-specific mixed effects models.

Result

Among the 48 435 subjects who had completed the respective questionnaire, 12 673 (26.7%, 87.8% of women) had followed at least one weight-loss diet in the previous three years. Diet plans prescribed by health professionals and diets conforming to official dietary recommendations were the most favourably perceived among all assessed weight-loss strategies. Alternatively, commercial diet plans and self-imposed dietary restrictions were more negatively perceived (Odds ratios (OR) for adherence difficulty 1.30 (95% confidence interval (0.99;1.7)) in men and OR 1.92 (1.76;2.10) in women compared to official nutritional guidelines; OR 1.06 (0.82;1.38) in men and OR 1.39 (1.26;1.54) in women respectively) compared to official nutritional guidelines.

Conclusion

Official dietary recommendations could be useful tools for maintaining a dietary balance while following a weight-loss diet.     

Dynamic perceptual changes in audiovisual simultaneity

Background

The timing at which sensory input reaches the level of conscious perception is an intriguing question still awaiting an answer. It is often assumed that both visual and auditory percepts have a modality specific processing delay and their difference determines perceptual temporal offset.

Methodology/Principal Findings

Here, we show that the perception of audiovisual simultaneity can change flexibly and fluctuates over a short period of time while subjects observe a constant stimulus. We investigated the mechanisms underlying the spontaneous alternations in this audiovisual illusion and found that attention plays a crucial role. When attention was distracted from the stimulus, the perceptual transitions disappeared. When attention was directed to a visual event, the perceived timing of an auditory event was attracted towards that event.

Conclusions/Significance

This multistable display illustrates how flexible perceived timing can be, and at the same time offers a paradigm to dissociate perceptual from stimulus-driven factors in crossmodal feature binding. Our findings suggest that the perception of crossmodal synchrony depends on perceptual binding of audiovisual stimuli as a common event.     

Changes In Actual And Perceived Physical Abilities In Clinically Obese Children: A 9-Month Multi-Component Intervention Study

Objectives

(1) To examine relationships among changes in physical activity, physical fitness and some psychosocial determinants of activity behavior in a clinical sample of obese children involved in a multi-component program; (2) to investigate the causal relationship over time between physical activity and one of its strongest correlates (i.e. perceived physical ability).

Methods

Self-reported physical activity and health-related fitness tests were administered before and after a 9-month intervention in 24 boys and 20 girls aged 8 to 11 years. Individuals’ perceptions of strength, speed and agility were assessed using the Perceived Physical Ability Scale, while body image was measured using Collins’ Child Figure Drawings.

Results

Findings showed that body mass index, physical activity, performances on throwing and weight-bearing tasks, perceived physical ability and body image significantly improved after treatment among obese children. Gender differences were found in the correlational analyses, showing a link between actual and perceived physical abilities in boys, but not in girls. For the specific measurement interval of this study, perception of physical ability was an antecedent and not a potential consequence of physical activity.

Conclusions

Results indicate that a multi-component activity program not based merely on a dose-effect approach enhances adherence of the participants and has the potential to increase the lifelong exercise skills of obese children. Rather than focusing entirely on diet and weight loss, findings support the inclusion of interventions directed toward improving perceived physical ability that is predictive of subsequent physical activity.     

Wind Speed Perception and Risk

Background

How accurately do people perceive extreme wind speeds and how does that perception affect the perceived risk? Prior research on human–wind interaction has focused on comfort levels in urban settings or knock-down thresholds. No systematic experimental research has attempted to assess people''s ability to estimate extreme wind speeds and perceptions of their associated risks.

Method

We exposed 76 people to 10, 20, 30, 40, 50, and 60 mph (4.5, 8.9, 13.4, 17.9, 22.3, and 26.8 m/s) winds in randomized orders and asked them to estimate wind speed and the corresponding risk they felt.

Results

Multilevel modeling showed that people were accurate at lower wind speeds but overestimated wind speeds at higher levels. Wind speed perceptions mediated the direct relationship between actual wind speeds and perceptions of risk (i.e., the greater the perceived wind speed, the greater the perceived risk). The number of tropical cyclones people had experienced moderated the strength of the actual–perceived wind speed relationship; consequently, mediation was stronger for people who had experienced fewer storms.

Conclusion

These findings provide a clearer understanding of wind and risk perception, which can aid development of public policy solutions toward communicating the severity and risks associated with natural disasters.     

Physical Activity and Perceived Insecurity from Crime in Adults: A Population-Based Study

Background

The present study aimed to describe the perception of safety from crime in the neighborhood and to evaluate its association with leisure-time and transport-related physical activity in adults.

Methods

A cross-sectional population based study was conducted in the urban area of Pelotas, Brazil, in 2012. Perceived insecurity from crime in the neighborhood was measured using the Neighborhood Environment Walkability Scale (NEWS) and the City Stress Inventory (CSI). Physical activity was measured using an adapted version of the leisure and transportation sections of the long version of the International Physical Activity Questionnaire.

Results

Overall, 52.3% (95%CI49.0; 55.6) of the participants reported perceived exposure to an unsafe neighborhood. Subjects who practiced 150 or more minutes per week of physical activity during leisure-time and transportation were 10.5% (95%CI9.0; 12.0) and 51.7% (95%CI 48.7; 54.7), respectively. There were no significant associations between physical activity (leisure-time or transport-related) and perceived insecurity from crime, neither in unadjusted nor in adjusted analyses.

Conclusion

There was no evidence that the perception of safety from crime is associated to higher physical activity levels among Brazilian adults.     

Are Lay People Good at Recognising the Symptoms of Schizophrenia?

Aim

The aim of this study was to explore the general public’s perception of schizophrenia symptoms and the need to seek-help for symptoms. The recognition (or ‘labelling’) of schizophrenia symptoms, help-seeking behaviours and public awareness of schizophrenia have been suggested as potentially important factors relating to untreated psychosis.

Method

Participants were asked to rate to what extent they believe vignettes describing classic symptoms (positive and negative) of schizophrenia indicate mental illness. They were also asked if the individuals depicted in the vignettes required help or treatment and asked to suggest what kind of help or treatment.

Results

Only three positive symptoms (i.e., Hallucinatory behaviour, Unusual thought content and Suspiciousness) of schizophrenia were reasonably well perceived (above 70%) as indicating mental illness more than the other positive or negative symptoms. Even when the participants recognised that the symptoms indicated mental illness, not everyone recommended professional help.

Conclusion

There may be a need to improve public awareness of schizophrenia and psychosis symptoms, particularly regarding an awareness of the importance of early intervention for psychosis.     

Health Beliefs and Practices Related to Dengue Fever: A Focus Group Study

Background

This qualitative study aimed to provide an in-depth understanding of the meaning of dengue fever (DF) amongst people living in a dengue endemic region, dengue prevention and treatment-seeking behaviours. The Health Belief Model was used as a framework to explore and understand dengue prevention behaviours.

Methods

A total of 14 focus group discussions were conducted with 84 Malaysian citizens of different socio-demographic backgrounds between 16^th December, 2011 and 12^th May, 2012.

Results

The study revealed that awareness about DF and prevention measures were high. The pathophysiology of dengue especially dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) were rarely known; as a result, it was seen as deadly by some but was also perceived as easily curable by others without a basis of understanding. Young adults and elderly participants had a low perception of susceptibility to DF. In general, the low perceived susceptibility emerged as two themes, namely a perceived natural ability to withstand infection and a low risk of being in contact with the dengue virus vector, Aedes spp. mosquitoes. The barriers to sustained self-prevention against dengue prevention that emerged in focus groups were: i) lack of self-efficacy, ii) lack of perceived benefit, iii) low perceived susceptibility, and iv) unsure perceived susceptibility. Low perceived benefit of continued dengue prevention practices was a result of lack of concerted action against dengue in their neighborhood. Traditional medical practices and home remedies were widely perceived and experienced as efficacious in treating DF.

Conclusion

Behavioural change towards attaining sustainability in dengue preventive practices may be enhanced by fostering comprehensive knowledge of dengue and a change in health beliefs. Wide use of unconventional therapy for DF warrants the need to enlighten the public to limit their reliance on unproven alternative treatments.     

Run Charts Revisited: A Simulation Study of Run Chart Rules for Detection of Non-Random Variation in Health Care Processes

Background

A run chart is a line graph of a measure plotted over time with the median as a horizontal line. The main purpose of the run chart is to identify process improvement or degradation, which may be detected by statistical tests for non-random patterns in the data sequence.

Methods

We studied the sensitivity to shifts and linear drifts in simulated processes using the shift, crossings and trend rules for detecting non-random variation in run charts.

Results

The shift and crossings rules are effective in detecting shifts and drifts in process centre over time while keeping the false signal rate constant around 5% and independent of the number of data points in the chart. The trend rule is virtually useless for detection of linear drift over time, the purpose it was intended for.     

Vibration influences haptic perception of surface compliance during walking

Background

The haptic perception of ground compliance is used for stable regulation of dynamic posture and the control of locomotion in diverse natural environments. Although rarely investigated in relation to walking, vibrotactile sensory channels are known to be active in the discrimination of material properties of objects and surfaces through touch. This study investigated how the perception of ground surface compliance is altered by plantar vibration feedback.

Methodology/Principal Findings

Subjects walked in shoes over a rigid floor plate that provided plantar vibration feedback, and responded indicating how compliant it felt, either in subjective magnitude or via pairwise comparisons. In one experiment, the compliance of the floor plate was also varied. Results showed that perceived compliance of the plate increased monotonically with vibration feedback intensity, and depended to a lesser extent on the temporal or frequency distribution of the feedback. When both plate stiffness (inverse compliance) and vibration amplitude were manipulated, the effect persisted, with both factors contributing to compliance perception. A significant influence of vibration was observed even for amplitudes close to psychophysical detection thresholds.

Conclusions/Significance

These findings reveal that vibrotactile sensory channels are highly salient to the perception of surface compliance, and suggest that correlations between vibrotactile sensory information and motor activity may be of broader significance for the control of human locomotion than has been previously acknowledged.     

Characterizing hospital workers' willingness to respond to a radiological event

Introduction

Terrorist use of a radiological dispersal device (RDD, or “dirty bomb”), which combines a conventional explosive device with radiological materials, is among the National Planning Scenarios of the United States government. Understanding employee willingness to respond is critical for planning experts. Previous research has demonstrated that perception of threat and efficacy is key in the assessing willingness to respond to a RDD event.

Methods

An anonymous online survey was used to evaluate the willingness of hospital employees to respond to a RDD event. Agreement with a series of belief statements was assessed, following a methodology validated in previous work. The survey was available online to all 18,612 employees of the Johns Hopkins Hospital from January to March 2009.

Results

Surveys were completed by 3426 employees (18.4%), whose demographic distribution was similar to overall hospital staff. 39% of hospital workers were not willing to respond to a RDD scenario if asked but not required to do so. Only 11% more were willing if required. Workers who were hesitant to agree to work additional hours when required were 20 times less likely to report during a RDD emergency. Respondents who perceived their peers as likely to report to work in a RDD emergency were 17 times more likely to respond during a RDD event if asked. Only 27.9% of the hospital employees with a perception of low efficacy declared willingness to respond to a severe RDD event. Perception of threat had little impact on willingness to respond among hospital workers.

Conclusions

Radiological scenarios such as RDDs are among the most dreaded emergency events yet studied. Several attitudinal indicators can help to identify hospital employees unlikely to respond. These risk-perception modifiers must then be addressed through training to enable effective hospital response to a RDD event.     

Visfatin induces sickness responses in the brain

Background/Objective

Visfatin, also known as nicotiamide phosphoribosyltransferase or pre-B cell colony enhancing factor, is a pro-inflammatory cytokine whose serum level is increased in sepsis and cancer as well as in obesity. Here we report a pro-inflammatory role of visfatin in the brain, to mediate sickness responses including anorexia, hyperthermia and hypoactivity.

Methodology

Rats were intracerebroventricularly (ICV) injected with visfatin, and changes in food intake, body weight, body temperature and locomotor activity were monitored. Real-time PCR was applied to determine the expressions of pro-inflammatory cytokines, proopiomelanocortin (POMC) and prostaglandin-synthesizing enzymes in their brain. To determine the roles of cyclooxygenase (COX) and melanocortin in the visfatin action, rats were ICV-injected with visfatin with or without SHU9119, a melanocortin receptor antagonist, or indomethacin, a COX inhibitor, and their sickness behaviors were evaluated.

Principal Findings

Administration of visfatin decreased food intake, body weight and locomotor activity and increased body temperature. Visfatin evoked significant increases in the levels of pro-inflammatory cytokines, prostaglandin-synthesizing enzymes and POMC, an anorexigenic neuropeptide. Indomethacin attenuated the effects of visfatin on hyperthermia and hypoactivity, but not anorexia. Further, SHU9119 blocked visfatin-induced anorexia but did not affect hyperthermia or hypoactivity.

Conclusions

Visfatin induced sickness responses via regulation of COX and the melanocortin pathway in the brain.