The behavioural response of nematodes to chemical stimuli has been extensively investigated in some free-living and plant parasitic species. However, in animal parasitic species, little is yet known, particularly in regards to marine forms such as the whaleworm (Anisakis simplex). Previous studies showed that A. simplex L3-larvae tend to prefer fish tissue with high lipid content. The intention of this study was to investigate the behaviour of A. simplex L3 in response to different concentrations of fish lipid in further detail. This was done by an in vitro study based on larvae from cod (Gadus morhua). Ten larvae were placed in each of the culture containers containing agar that was separated into three segments of equal size. Three categories of agar were used containing 0, 2 and 7 % cod liver oil. A total of 900 larvae were included. The study consisted of three parts: The purpose of experiment I was to establish whether different lipid concentrations influenced the migration pattern at all. Experiment II was intended to examine whether A. simplex L3-larvae were able to actively search for lipids. Experiment III was set up to analyse the short-distance dispersion of the L3-larvae. Experiment I indicated that the L3-larvae move randomly but do not stop randomly since the tendency to move out of the start area was inversely correlated with lipid concentration. Experiment II indicates that the larvae are almost unable to select areas of high lipid concentrations when more than a few centimetres away. Experiment III showed that the L3-larvae prefer high-fat content and can seek it out over short distances.
Stimulus-specific adaptation (SSA), which describes adaptation to repeated sounds concurrent with the maintenance of responsiveness to uncommon ones, may be an important neuronal mechanism for the detection of and attendance to rare stimuli or for the detection of deviance. It is well known that GABAergic neurotransmission regulates several different response properties in central auditory system neurons and that GABA is the major inhibitory neurotransmitter acting in the medial geniculate body (MGB). The mechanisms underlying SSA are still poorly understood; therefore, the primary aim of the present study was to examine what role, if any, MGB GABAergic circuits play in the generation and/or modulation of SSA. Microiontophoretic activation of GABAA receptors (GABAARs) with GABA or with the selective GABAAR agonist gaboxadol significantly increased SSA (computed with the common SSA index, CSI) by decreasing responses to common stimuli while having a lesser effect on responses to novel stimuli. In contrast, GABAAR blockade using gabazine resulted in a significant decrease in SSA. In all cases, decreases in the CSI during gabazine application were accompanied by an increase in firing rate to the stimulus paradigm. The present findings...
While a number of studies have documented the persistent presence of chikungunya virus (CHIKV) in muscle tissue with primary fibroblast as the preferable cell target, little is known regarding the alterations that take place in muscle tissue in response to CHIKV infection. Hence, in the present study a permissive mouse model of CHIKV infection was established and characterized in order to understand the pathophysiology of the disease. The two dimensional electrophoresis of muscle proteome performed for differential analysis indicated a drastic reprogramming of the proteins from various classes like stress, inflammation, cytoskeletal, energy and lipid metabolism. The roles of the affected proteins were explained in relation to virus induced myopathy which was further supported by the histopathological and behavioural experiments proving the lack of hind limb coordination and other loco-motor abnormalities in the infected mice. Also, the level of various pro-inflammatory mediators like IL-6, MCP-1, Rantes and TNF-α was significantly elevated in muscles of infected mice. Altogether this comprehensive study of characterizing CHIKV induced mouse myopathy provides many potential targets for further evaluation and biomarker study.
Negative emotional states in humans are associated with a negative (pessimistic) response bias towards ambiguous cues in judgement tasks. Every mammalian young is eventually weaned; this period of increasing nutritional and social independence from the dam is associated with a pronounced behavioural response, especially when weaning is abrupt as commonly occurs in farm animals. The aim of the current study was to test the effect of separation from the cow on the responses of dairy calves in a judgement task. Thirteen Holstein calves were reared with their dams and trained to discriminate between red and white colours displayed on a computer monitor. These colours predicted reward or punishment outcomes using a go/no-go task. A reward was provided when calves approached the white screen and calves were punished with a timeout when they approached the red screen. Calves were then tested with non-reinforced ambiguous probes (screen colours intermediate to the two training colours). “GO” responses to these probes averaged (± SE) 72±3.6 % before separation but declined to 62±3.6 % after separation from the dam. This bias was similar to that shown by calves experiencing pain in the hours after hot-iron dehorning. These results provide the first evidence of a pessimistic judgement bias in animals following maternal separation and are indicative of low mood.
Animals exposed to anthropogenic disturbance make trade-offs between perceived risk and the cost of leaving disturbed areas. Impact assessments tend to focus on overt behavioural responses leading to displacement, but trade-offs may also impact individual energy budgets through reduced foraging performance. Previous studies found no evidence for broad-scale displacement of harbour porpoises exposed to impulse noise from a 10 day two-dimensional seismic survey. Here, we used an array of passive acoustic loggers coupled with calibrated noise measurements to test whether the seismic survey influenced the activity patterns of porpoises remaining in the area. We showed that the probability of recording a buzz declined by 15% in the ensonified area and was positively related to distance from the source vessel. We also estimated received levels at the hydrophones and characterized the noise response curve. Our results demonstrate how environmental impact assessments can be developed to assess more subtle effects of noise disturbance on activity patterns and foraging efficiency.
Understanding the regulation of gene activities depending on DNA methylation has been the subject of much recent study. However, although polymorphisms of the HTR2A gene have been associated with both obesity and psychiatric disorders, the role of HTR2A gene methylation in these illnesses remains uncertain. The aim of this study was to evaluate the association of HTR2A gene promoter methylation levels in white blood cells (WBC) with obesity traits and depressive symptoms in individuals with metabolic syndrome (MetS) enrolled in a behavioural weight loss programme. Analyses were based on 41 volunteers (mean age 49 ± 1 year) recruited within the RESMENA study. Depressive symptoms (as determined using the Beck Depression Inventory), anthropometric and biochemical measurements were analysed at the beginning and after six months of weight loss treatment. At baseline, DNA from WBC was isolated and cytosine methylation in the HTR2A gene promoter was quantified by a microarray approach. In the whole-study sample, a positive association of HTR2A gene methylation with waist circumference and insulin levels was detected at baseline. Obesity measures significantly improved after six months of dietary treatment, where a lower mean HTR2A gene methylation at baseline was associated with major reductions in body weight...
An automated, non-invasive system for monitoring of thermoregulation has the potential to mitigate swine diseases through earlier detection. Measurement of radiated temperature of groups of animals by infrared thermography (IRT) is an essential component of such a system. This study reports on the feasibility of monitoring the radiated temperature of groups of animals as a biomarker of immune response using vaccination as a model for febrile disease. In Study A, weaned pigs were either treated with an intramuscular vaccine (FarrowSure Gold), a sham injection of 0.9% saline or left as untreated controls. An infrared thermal camera (FLIR A320) was fixed to the ceiling directly above the pen of animals, and recorded infrared images of the treatment groups at 5 min intervals. The effect on temperature of the spatial distribution of pigs within the pen was significant, with higher temperatures recorded when pigs were grouped together into a single cluster. A higher frequency of clustering behaviour was observed in vaccinated animals compared with controls during a period of the afternoon ~4 to 7 h post-vaccination. The daily mean of the maximum image temperature was significantly higher in vaccinated animals compared with control and sham-treated animals. In the vaccination treated group...
Crowd evacuations are paradigmatic examples for collective behaviour, as interactions between individuals lead to the overall movement dynamics. Approaches assuming that all individuals interact in the same way have significantly improved our understanding of pedestrian crowd evacuations. However, this scenario is unlikely, as many pedestrians move in social groups that are based on friendship or kinship. We test how the presence of social groups affects the egress time of individuals and crowds in a representative crowd evacuation experiment. Our results suggest that the presence of social groups increases egress times and that this is largely due to differences at two stages of evacuations. First, individuals in social groups take longer to show a movement response at the start of evacuations, and, second, they take longer to move into the vicinity of the exits once they have started to move towards them. Surprisingly, there are no discernible time differences between the movement of independent individuals and individuals in groups directly in front of the exits. We explain these results and discuss their implications. Our findings elucidate behavioural differences between independent individuals and social groups in evacuations. Such insights are crucial for the control of crowd evacuations and for planning mass events.
Rodents and primates deprived of early social contact exhibit deficits in learning and behavioural flexibility. They often also exhibit apparent signs of elevated anxiety, although the relationship between these effects has not been studied. To investigate whether dairy calves are similarly affected, we first compared calves housed in standard individual pens (n = 7) to those housed in a dynamic group with access to their mothers (n = 8). All calves learned to approach the correct stimulus in a visual discrimination task. Only one individually housed calf was able to re-learn the task when the stimuli were reversed, compared to all but one calf from the group. A second experiment investigated whether this effect might be explained by anxiety in individually housed animals interfering with their learning, and tested varying degrees of social contact in addition to the complex group: pair housing beginning early (approximately 6 days old) and late (6 weeks old). Again, fewer individually reared calves learned the reversal task (2 of 10 or 20%) compared to early paired and grouped calves (16 of 21 or 76% of calves). Late paired calves had intermediate success. Individually housed calves were slower to touch novel objects, but the magnitude of the fear response did not correlate with reversal performance. We conclude that individually housed calves have learning deficits...
For listeners familiar with Western twelve-tone equal-tempered (12-TET) music, a novel microtonal tuning system is expected to present additional processing challenges. We aimed to determine whether this was the case, focusing on the extent to which our perceptions can be considered bottom-up (psychoacoustic and primarily perceptual) and top-down (dependent on familiarity and cognitive processing). We elicited both overt response ratings, and covert event-related potentials (ERPs), so as to compare subjective impressions of sounds with the neurophysiological processing of the acoustic signal. We hypothesised that microtonal intervals are perceived differently from 12-TET intervals, and that the responses of musicians (n = 10) and non-musicians (n = 10) are distinct. Two-note chords were presented comprising 12-TET intervals (consonant and dissonant) or microtonal (quarter tone) intervals, and ERP, subjective roughness ratings, and liking ratings were recorded successively. Musical experience mediated the perception of differences between dissonant and microtone intervals, with non-musicians giving similar ratings for each, and musicians preferring dissonant over the less commonly used microtonal intervals, rating them as less rough. ERP response amplitude was greater for consonant intervals than other intervals. Musical experience interacted with interval type...
Previous research on predator-induced phenotypic plasticity mostly focused on responses in morphology, developmental time and/or behaviour during early life stages, but the potential significance of anticipatory parental responses has been investigated less often. In this study I examined behavioural and maternal responses of gravid female smooth newts, Lissotriton vulgaris, in the presence of chemical cues originating from invertebrate predators, Acilius sulcatus water beetles and Aeshna cyanea dragonfly larvae. More specifically, I tested the extent of oviposition preference, plasticity in egg-wrapping behaviour and plasticity in egg size when females had the possibility to lay eggs at oviposition sites with and without predator cues during overnight trials. I found that individuals did not avoid laying eggs in the environment with predator cues; however, individuals that deposited eggs into both environments adjusted the size of the laid eggs to the perceived environment. Females deposited larger eggs earlier in the season but egg size decreased with time in the absence of predator cues, whereas individuals laid eggs of average size throughout the investigated reproductive period when such cues were present. Also, egg size was found to be positively related to hatching success. Individuals did not adjust their wrapping behaviour to the presence of predator cues...
Animal welfare depends on the possibility to express species-specific behaviours and can
be strongly compromised in socially and environmentally deprived conditions. Nesting
materials and refuges are very important resources to express these behaviours and should
be considered as housing supplementation items. We evaluated the effects of one item of
housing supplementation in standard settings in laboratory mice. C57BL/6JOlaHsd (B6) and
BALB/cOlaHsd (BALB) young male and female mice, upon arrival, were housed in groups of
four in standard laboratory cages and after 10 days of acclimatization, a red transparent
plastic triangular-shaped Mouse House™ was introduced into half of the home cages. Animals
with or without a mouse house were observed in various contexts for more than one month.
Body weight gain and food intake, home cage behaviours, emotionality and response to
standard cage changing procedures were evaluated. The presence of a mouse house in the
home cage did not interfere with main developmental and behavioural parameters or
emotionality of BALB and B6 male and female mice compared with controls. Both strains
habituated to the mouse house in about a week, but made use of it differently, with BALB
mice using the house more than the B6 strain. Our results suggest that mice habituated to
the mouse house rather quickly without disrupting their home cage activities. Scientists
can thus be encouraged to use mouse houses...
A plasticidade fenotípica define a habilidade do organismo em modificar sua fisiologia/morfologia em resposta às condições ambientais, sem que mudanças genéticas sejam necessárias (Scheiner). Este estudo foi desenvolvido para verificar mudanças fisiológicas, morfológicas e comportamentais em duas diferentes populações de Zabrotes subfasciatus (Boheman) (Coleoptera, Bruchidae) associadas ao consumo de diferentes variedades de feijão (Phaseolus vulgaris L.) (Fabaceae). A longevidade das fêmeas (tempo médio de sobrevivência), a fertilidade e a preferência destas pelo sítio de oviposição, assim como o tamanho e os níveis de assimetria flutuante (AF) foram registrados. Houve respostas plásticas fisiológicas e modificação morfológica em Z. subfasciatus. Esta espécie é generalista para consumo e oviposição em diferentes variedades de feijão e sua habilidade para utilizar distintos hospedeiros contribui para a sobrevivência da população e a torna menos sujeita à extinção. O princípio de Hopkins, que mostra a influência da experiência prévia na escolha de sítios para oviposição, não foi confirmado para esta espécie. As populações estudadas apresentaram respostas plásticas distintas a tratamentos similares...
Fonte: Quens UniversityPublicador: Quens University
Tipo: Tese de DoutoradoFormato: 177940 bytes; application/pdf
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The response of male Siberian hamsters (Phodopus sungorus) to situations of high- and low-risk of sperm competition was investigated. The copulatory behaviour of the males was examined during 2-h mating trials and changes in ejaculate characteristics were examined by dissecting females after the trials. Males in the competitor-male treatment had the lowest mean ejaculatory-series duration, postejaculatory interval, and ejaculatory-lock duration, indicating that males will alter the amount of time they spend in various stages of their ejaculatory series in response to a high risk of sperm competition. Copulatory behaviour of males in the castrated-male treatment was intermediate between the competitor-male and lone-male treatments, indicating that the mating males responded to the physical presence of another male but differentiate between intact and castrated males. Males in the competitor-male treatment delivered significantly more ejaculations than males in the other two treatments. When time to first mount the female after initial introduction was examined, a significant negative correlation was found between the (log) time to first mount and the total number of ejaculations a male achieved in the castrated-male treatment. Males in the competitor-male treatment transferred 20-26% more sperm than males in the other two treatments but significant differences were only found between the competitor- and lone-male treatments. Males in the competitor-male treatment transferred significantly more sperm to heavier females...
ABSTRACTStudies suggest that frugivorous bats search and select fruit mainly by olfaction so that they can be attracted by smell alone. The aim of this study was to evaluate, in captivity, the behavioural response (number of foraging attempts) of Artibeus lituratus and Carollia perspicillata offered essential oils extracted from ripe fruit of Ficus insipida (Moraceae) and Piper hispidum (Piperaceae) as well as intact fruit wrapped in gauze to attract bats with reduced visual stimuli. Based on previous reports, we hypothesized that A.lituratuswould exhibit preference for Ficusfruits/oil while C. perspicillatawould prefer Piperfruit/oil. Four arrangements of these attractants were tested in triplicate: P. hispidum fruit vs. F. insipida fruit, P.hispidumoil vs. F. insipidaoil,P. hispidumoil vs. F. insipidafruit and P. hispidumfruit vs. F. insipidaoil. As expected, in all tests, A. lituratusshowed the highest number of foraging attempts in F. insipida while C. perspicillatain those of P. hispidum.Based on the number of foraging attempts both species exhibited a positive response to their favorite fruit genera, though the differences were not always statistically significant. The results confirm the importance of smell in fruit choice by these species.
The Auditory Response Cradle (ARC) is a fully automated microprocessor controlled machine that was designed for the hearing screening of full term neonates. In order to evaluate the ARC, 6000 babies were screened at a district maternity hospital over a period of three years. Every infant subsequently entered a three year follow up programme. One hundred and two babies (1.7%) failed the ARC screen (that is, they failed two ARC tests) and 20 of these were found to have some hearing impairment: in 10 it was severe (80-90 dBHL), in seven moderate (45-60 dBHL), and in three it was mild to moderate (less than 45 dBHL). In addition, of the 20 babies who failed a first test and were discharged before a second could be performed, two were confirmed to have a severe hearing loss; 79 infants failing the screen were cleared on further testing, giving the ARC a false positive rate of 1.3%. On following up all 6000 infants for three years, seven children who passed the neonatal screen were subsequently found to have a hearing loss. For two babies the aetiology was unknown but for five the hearing impairment was either due to a hereditary progressive loss or definite postnatal factors. Progressive and acquired hearing losses cannot be detected at a neonatal screen and this emphasises the need for follow up screens at other stages in the child's life. In this long term study the ARC has been found to have a high detection rate for severe hearing loss and confirms the practical possibility of using a behavioural technique for the universal screening of hearing in neonates.
The ability to signal individual identity using vocal signals and distinguish between conspecifics based on vocal cues is important in several mammal species. Furthermore, it can be important for receivers to differentiate between callers in reproductive contexts. In this study, we used acoustic analyses to determine whether male koala bellows are individually distinctive and to investigate the relative importance of different acoustic features for coding individuality. We then used a habituation-discrimination paradigm to investigate whether koalas discriminate between the bellow vocalisations of different male callers. Our results show that male koala bellows are highly individualized, and indicate that cues related to vocal tract filtering contribute the most to vocal identity. In addition, we found that male and female koalas habituated to the bellows of a specific male showed a significant dishabituation when they were presented with bellows from a novel male. The significant reduction in behavioural response to a final rehabituation playback shows this was not a chance rebound in response levels. Our findings indicate that male koala bellows are highly individually distinctive and that the identity of male callers is functionally relevant to male and female koalas during the breeding season. We go on to discuss the biological relevance of signalling identity in this species' sexual communication and the potential practical implications of our findings for acoustic monitoring of male population levels.
The biochemical and clinical response to massage in preterm infants was assessed. Eleven stable infants, of 29 weeks' median gestational age, median birth weight 980 g, and median postnatal age 20 days, were studied. Blood samples were obtained for the determination of adrenaline, noradrenaline, and cortisol 45 minutes before the start of massage and approximately one hour after completion of massage. Cortisol, but not catecholamine, concentrations decreased consistently after massage (median difference -35.8 nmol/l; 95% confidence interval -0.5 to -94.0, Wilcoxon matched pairs). There was a slight decrease in skin temperature (median difference -0.36 degrees C, 95% confidence interval -0.09 to -0.65) but there was no change in oxygenation or oxygen requirement. This study has shown that it is possible to detect an objective hormonal change following a supposedly 'non-therapeutic' intervention in preterm infants. The development of such methods of assessment are likely to be of particular relevance in the extremely immature or ill neonate in whom behavioural evaluation cannot play more than a limited part.
Spermine oxidase is a FAD-containing enzyme involved in polyamines catabolism, selectively oxidizing spermine to produce H2O2, spermidine, and 3-aminopropanal. Spermine oxidase is highly expressed in the mouse brain and plays a key role in regulating the levels of spermine, which is involved in protein synthesis, cell division and cell growth. Spermine is normally released by neurons at synaptic sites where it exerts a neuromodulatory function, by specifically interacting with different types of ion channels, and with ionotropic glutamate receptors. In order to get an insight into the neurobiological roles of spermine oxidase and spermine, we have deregulated spermine oxidase gene expression producing and characterizing the transgenic mouse model JoSMOrec, conditionally overexpressing the enzyme in the neocortex. We have investigated the effects of spermine oxidase overexpression in the mouse neocortex by transcript accumulation, immunohistochemical analysis, enzymatic assays and polyamine content in young and aged animals. Transgenic JoSMOrec mice showed in the neocortex a higher H2O2 production in respect to Wild-Type controls, indicating an increase of oxidative stress due to SMO overexpression. Moreover, the response of transgenic mice to excitotoxic brain injury...
Autism Spectrum Disorders (ASD) are neurodevelopmental disorders characterised by impaired social interaction and communication, restricted interests and repetitive behaviours. The severity of these characteristics are posited to lie on a continuum extending into the typical population, and typical adults' performance on behavioural tasks that are impaired in ASD is correlated with the extent to which they display autistic traits (as measured by Autism Spectrum Quotient, AQ). Individuals with ASD also show structural and functional differences in brain regions involved in social perception. Here we show that variation in AQ in typically developing individuals is associated with altered brain activity in the neural circuit for social attention perception while viewing others' eye gaze. In an fMRI experiment, participants viewed faces looking at variable or constant directions. In control conditions, only the eye region was presented or the heads were shown with eyes closed but oriented at variable or constant directions. The response to faces with variable vs. constant eye gaze direction was associated with AQ scores in a number of regions (posterior superior temporal sulcus, intraparietal sulcus, temporoparietal junction, amygdala...