Exploratory and dust-bathing behaviour in laying hens kept in commercial aviaries and furnished cages

The aim of the present thesis was to identify management factors that affect the extent of exploratory behaviour (ground pecking, scratching) as well as quantitative and qualitative as-pects of dust-bathing behaviour in laying hens kept in commercial furnished cages (‘small group housing’) and aviaries. Based on the results, it should be considered which management measures can be recommended for farmers to enhance hen welfare. The feasibility of direct observations of dust-bathing behaviour as well as video observations of exploratory and dust-bathing behaviour was tested in two aviaries. The direct observations were judged to be unfeasible under the conditions encountered. For the analysis of the video recordings, different sampling intervals for instantaneous scan sampling, different extents of observation time, and intra- and inter-observer reliabilities were compared and the most ap-propriate observation scheme selected. Applying the selected scheme (observing the first 16 minutes of every hour distributed over two consecutive light days with a sample interval of two minutes), within the range of environmental conditions found in 22 aviaries, pecking, scratching and dust-bathing behaviour was performed on average 25, 2 and 7 % of the obser-vation time. Hen numbers in the litter were positively associated with stocking density and group size. More scratching was performed with increasing litter height as well as in humid litter. If no litter had been provided, thus substrate consisted of dust and faeces, a reduced proportion of dust-bathing was found. The same method was then used in 16 furnished cage systems. On average 12 % of the total hen number were found on the scratching mats. The hens spent 8 % of the observed time pecking at the mat, 4 % dust-bathing and 0.4 % scratch-ing. Higher proportions were found on the mats and more dust-bathing behaviour occurred, if substrate was provided. Also with increasing light intensity and stocking density more hens were observed on the mats. More pecking and scratching occurred in conditions of higher stocking density, probably due to social facilitation, and of increased mat area per hen. With increasing mat numbers per cage less pecking was observed. Wider mats led to increased dust-bathing behaviour. Finally, 129 dust-baths recorded in 17 aviaries were analysed in detail. On average they lasted 17 minutes, with the tossing phase taking 69 % of this time, including on average 2 vertical wing shakes and 3 scratches with one leg per minute tossing phase. Dust-bath duration de-creased with increasing litter height. Litter type influenced all recorded parameters: dust-bath duration was highest on straw and lowest on fine material and fine material mixed with straw, where on both also the proportion of the tossing phase was lowest. The number of vertical wing shakes during the dust-bath was highest on straw and lowest on fine material mixed with straw as against the frequency of vertical wing shaking that was lowest on straw and highest on fine material. If dust-bathing hens were disturbed twice or more, dust-bathing duration decreased. With increasing light intensity a decreased proportion of the tossing phase as well as a reduced number of vertical wing shakes were recorded. Possibly the light stimulated the hens to dust-bath more often with less tossing behaviour per performance. The observed variation of the dust-bathing parameters could reflect successful adaptation or frustration of the hens. The litter and light conditions on the investigated farms were predominantly restrictive in terms of stimulation of exploration and dust-bathing behaviour. Thus, it was only possible to analyse possible associations between these factors and exploration and dust-bathing behav-iour within the range found. Based on the results the following management recommendations can be given: To allow hens in furnished cages more normal activity, substrate availability should be improved and mat space and light intensity increased. With regard to aviaries as well litter availability should be improved. Litter height should not be too low. Disturbances during dust-bathing should be prevented, but no influencing factors could be identified.

Cellular prion protein modulates defensive attention and innate fear-induced behaviour evoked in transgenic mice submitted to an agonistic encounter with the tropical coral snake Oxyrhopus guibei

The cellular prion protein (PrPC) is a neuronal anchored glycoprotein that has been associated with distinct functions in the CNS, such as cellular adhesion and differentiation, synaptic plasticity and cognition. Here we investigated the putative involvement of the PrPC in the innate fear-induced behavioural reactions in wild-type (WT), PrPC knockout (Prnp(0/0)) and the PrPC overexpressing Tg-20 mice evoked in a prey versus predator paradigm. The behavioural performance of these mouse strains in olfactory discrimination tasks was also investigated. When confronted with coral snakes, mice from both Prnp(0/0) and Tg-20 strains presented a significant decrease in frequency and duration of defensive attention and risk assessment, compared to WT mice. Tg-20 mice presented decreased frequency of escape responses, increased exploratory behaviour, and enhancement of interaction with the snake, suggesting a robust fearlessness caused by PrPC overexpression. Interestingly, there was also a discrete decrease in the attentional defensive response (decreased frequency of defensive alertness) in Prnp(0/0) mice in the presence of coral snakes. Moreover, Tg-20 mice presented an increased exploration of novel environment and odors. The present findings indicate that the PrPC overexpression causes hyperactivity, fearlessness, and increased preference for visual, tactile and olfactory stimuli-associated novelty, and that the PrPC deficiency might lead to attention deficits. These results suggest that PrPC exerts an important role in the modulation of innate fear and novelty-induced exploration. (C) 2008 Published by Elsevier B.V.

GABA(A) receptor blockade in dorsomedial and ventromedial nuclei of the hypothalamus evokes panic-like elaborated defensive behaviour followed by innate fear-induced antinociception

Dysfunction in the hypothalamic GABAergic system has been implicated in panic syndrome in humans. Furthermore, several studies have implicated the hypothalamus in the elaboration of pain modulation. Panic-prone states are able to be experimentally induced in laboratory animals to study this phenomenon. The aim of the present work was to investigate the involvement of medial hypothalamic nuclei in the organization of panic-like behaviour and the innate fear-induced oscillations of nociceptive thresholds. The blockade of GABA(A) receptors in the neuronal substrates of the ventromedial. or dorsomedial hypothalamus was followed by elaborated defensive panic-like reactions. Moreover, innate fear-induced antinociception was consistently elicited after the escape behaviour. The escape responses organized by the dorsomedial and ventromedial hypothalamic nuclei were characteristically more elaborated, and a remarkable exploratory behaviour was recorded during GABA(A) receptor blockade in the medial hypothalamus. The motor characteristic of the elaborated defensive escape behaviour and the patterns of defensive alertness and defensive immobility induced by microinjection of the bicuculline either into the dorsomedial. or into the ventromedial hypothalamus were very similar. This was followed by the same pattern of innate fear-induced antinociceptive response that lasted approximately 40 min after the elaborated defensive escape reaction in both cases. These findings suggest that dysfunction of the GABA-mediated neuronal system in the medial hypothalamus causes panic-like responses in laboratory animals, and that the elaborated escape behaviour organized in both dorsomedial and ventromedial hypothalamic nuclei are followed by significant innate-fear-induced antinociception. Our findings indicate that the GABA(A) receptor of dorsomedial and ventromedial hypothalamic nuclei are critically involved in the modulation of panic-like behaviour. (C) 2009 Elsevier B.V. All rights reserved.

Social structure emerges via the interaction between local ecology and individual behaviour.

1. The formation of groups is a fundamental aspect of social organization, but there are still many questions regarding how social structure emerges from individuals making non-random associations. 2. Although food distribution and individual phenotypic traits are known to separately influence social organization, this is the first study, to our knowledge, experimentally linking them to demonstrate the importance of their interaction in the emergence of social structure. 3. Using an experimental design in which food distribution was either clumped or dispersed, in combination with individuals that varied in exploratory behaviour, our results show that social structure can be induced in the otherwise non-social European shore crab (Carcinus maenas). 4. Regardless of food distribution, individuals with relatively high exploratory behaviour played an important role in connecting otherwise poorly connected individuals. In comparison, low exploratory individuals aggregated into cohesive, stable subgroups (moving together even when not foraging), but only in tanks where resources were clumped. No such non-foraging subgroups formed in environments where food was evenly dispersed. 5. Body size did not accurately explain an individual's role within the network for either type of food distribution. 6. Because of their synchronized movements and potential to gain social information, groups of low exploratory crabs were more effective than singletons at finding food. 7. Because social structure affects selection, and social structure is shown to be sensitive to the interaction between ecological and behavioural differences among individuals, local selective pressures are likely to reflect this interaction.

Effects of reflection and social isolation on crayfish behaviour /

Visual stimuli and socialization influence exploratory behaviour in crayfish. The predominant components of spontaneous exploratory behaviour were determined by observing the activity of solitary adult crayfish (Procambarus clarkii) in a glass aquarium containing fresh water and no objects. Five distinct behaviours were observed: rearing up (climbing on the wall), turning around, cornering (facing the comer), backward walking, and crossing (crossing the midline of the aquarium). The frequency of rearing up, cornering and turning around decreased when reflection from the glass wall was blocked with black cardboard, black paint or non-reflective transparent plastic. In a tank containing mirrors on one side and non-reflective plastic on the other, crayfish cornered, reared up, and turned around more in front of the mirrors. Socialization was necessary for crayfish to respond to the reflection. Crayfish that were housed in pairs for two weeks exhibited more rearing up, turning around and cornering in front of the mirrors than in the non-reflective side. Crayfish isolated for two weeks did not show these differences. Socialized crayfish also exhibited more rearing up, turning around and cornering than did isolated crayfish. Thus, crayfish respond to visual stimuli provided by a glass tank, but the responds depends on socialization.

Social separation and diazepam withdrawal increase anxiety in the elevated plus-maze and serotonin turnover in the median raphe and hippocampus

The present work aimed to evaluate the effects of social separation for 14 days (chronic stress) and of withdrawal from a 14-day treatment with diazepam (acute stress) on the exploratory behaviour of male rats in the elevated plus-maze and on serotonin (5-hydroxytryptamine) turnover in different brain structures. Social separation had an anxiogenic effect, evidenced by fewer entries into, and less time spent on the open arms of the elevated plus-maze. Separation also selectively increased 5-hydroxytryptamine turnover in the hippocampus and median raphe nucleus. Diazepam withdrawal had a similar anxiogenic effect in grouped animals and increased 5-hydroxytryptamine turnover in the same brain structures. Chronic treatment with imipramine during the 14 days of separation prevented the behavioural and neurochemical changes caused by social separation. It is suggested that the increase in anxiety determined by both acute and chronic stress is mediated by the activation of the median raphe nucleus-hippocampal 5-hydroxytryptamine pathway.

Antidepressant-like effects of cannabidiol in mice: possible involvement of 5-HT(1A) receptors

Background and purpose: Cannabidiol (CBD) is a non-psychotomimetic compound from Cannabis sativa that induces anxiolytic- and antipsychotic-like effects in animal models. Effects of CBD may be mediated by the activation of 5-HT(1A) receptors. As 5-HT(1A) receptor activation may induce antidepressant-like effects, the aim of this work was to test the hypothesis that CBD would have antidepressant-like activity in mice as assessed by the forced swimming test. We also investigated if these responses depended on the activation of 5-HT(1A) receptors and on hippocampal expression of brain-derived neurotrophic factor (BDNF). Experimental approach: Male Swiss mice were given (i.p.) CBD (3, 10, 30, 100 mg.kg(-1)), imipramine (30 mg.kg(-1)) or vehicle and were submitted to the forced swimming test or to an open field arena, 30 min later. An additional group received WAY100635 (0.1 mg.kg(-1), i.p.), a 5-HT(1A) receptor antagonist, before CBD (30 mg.kg(-1)) and assessment by the forced swimming test. BDNF protein levels were measured in the hippocampus of another group of mice treated with CBD (30 mg.kg(-1)) and submitted to the forced swimming test. Key results: CBD (30 mg.kg(-1)) treatment reduced immobility time in the forced swimming test, as did the prototype antidepressant imipramine, without changing exploratory behaviour in the open field arena. WAY100635 pretreatment blocked CBD-induced effect in the forced swimming test. CBD (30 mg.kg(-1)) treatment did not change hippocampal BDNF levels. Conclusion and implications: CBD induces antidepressant-like effects comparable to those of imipramine. These effects of CBD were probably mediated by activation of 5-HT(1A) receptors. British Journal of Pharmacology (2010) 159, 122-128; doi:10.1111/j.1476-5381.2009.00521.x; published online 4 December 2009

Acute experimental Trypanosoma cruzi infection: establishing a murine model that utilises non-invasive measurements of disease parameters

Trypanosoma cruzi infection has a large public health impact in Latin American countries. Although the transmission rates via blood transfusions and insect vectors have declined sharply in the past 20 years due to policies of the Southern Cone countries, a large number of people are still at risk for infection. Currently, no accepted experimental model or descriptions of the clinical signs that occur during the course of acute murine infection are available. The aim of this work was to use non-invasive methods to evaluate the clinical signs of Balb/c mice infected with the Y strain of T. cruzi. The infected mice displayed evident clinical changes beginning in the third week of infection. The mice were evaluated based on physical characteristics, spontaneous activity, exploratory behaviour and physiological alterations. We hope that the results presented in this report provide parameters that complement the effective monitoring of trypanocidal treatment and other interventions used to treat experimental Chagas disease.

The Role of Non-Coercive Influence Tactics in Online Marketing

This thesis examines the effectiveness of non-coercive influence tactics in the context of consumer online behaviour. The objective of this study is to develop a comprehensive understanding of consumer online behaviour and the role of information types in affecting the consumer’s cognitive responses and behavioural outcomes. The theoretical part of the study examines the academic literature on consumer online behaviour and influence tactics used both in traditional buyer/seller relationships as well as in relationships mediated by online technologies. The empirical part of the study is carried out with four experiments that utilise non-coercive influence tactics to affect online consumer behaviour. The consumers included in this study are 18-28 year-old structural and civil engineering students in Finland, United Kingdom, United States and India. The findings suggest that non-coercive influence tactics are applicable in the online marketing context and generate cognitive responses of site awareness, site involvement and exploratory behaviour which subsequently results in behavioural outcomes of compliance, eWOM and site abandonment.

Warfarin-induced vitamin K deficiency is associated with cognitive and behavioral perturbations, and alterations in brain sphingolipids in rats

La Vitamine K (VK) est largement reconnue pour son rôle dans la coagulation sanguine toutefois, de plus en plus de travaux indiquent son implication dans la fonction cérébrale. La VK est requise pour l'activation de différentes protéines, par exemple la protéine Gas6, et la ménaquinone-4 (MK-4), le principal vitamère K dans le cerveau, est impliquée dans le métabolisme des sphingolipides. Dans un rapport précédent, nous avons montré qu'un régime alimentaire faible en VK tout au long de la vie était associé à des déficits cognitifs chez des rats âgés. La warfarine sodique est un puissant antagoniste de la VK qui agit en bloquant le cycle de la VK, provoquant un «déficit relatif de VK » au niveau cellulaire. À la lumière du rôle émergent de la VK dans le cerveau, la warfarine pourrait représenter un facteur de risque pour la fonction cérébrale. Ce travail est donc pertinente en raison de la forte proportion d'adultes traîtés à la warfarine sodique. Dans la présente étude, 14 rats mâles Wistar ont été traités avec 14 mg de warfarine/kg /jour (dans l'eau potable) et des injections sous-cutanées de VK (85 mg/kg), 3x/sem, pendant 10 semaines. Quatorze rats témoins ont été traités avec de l'eau normale et injectés avec une solution saline. Les rats ont été soumis à différents tests comportementaux après quoi les niveaux de phylloquinone, MK-4, sphingolipides (cérébroside, sulfatide, sphingomyéline, céramide et gangliosides), et les sous-types de gangliosides (GT1b, GD1a, GM1, GD1b), ont été évalués dans différentes régions du cerveau. Comparativement aux rats du groupe contrôle, les rats traités à la warfarine présentaient des latences plus longues au test de la piscine de Morris (p <0,05) ainsi qu'une hypoactivité et un comportement exploratoire plus faible au test de « l’open field » (p <0,05). Le traitement par warfarine a également entraîné une diminution spectaculaire du niveau de MK-4 dans toutes les régions du cerveau (p <0,001), une altération des concentrations de sphingolipidiques, en particulier dans le cortex frontal et le mésencéphale (p <0,05), et une perte de différences régionales sphingolipidiques, notamment pour les gangliosides. Le traitement par warfarine a été associé à un niveau inférieur de GD1a dans l'hippocampe et un niveau supérieur de GT1b dans le cortex préfrontal et le striatum. En conclusion, la déficience en VK induite par warfarine altère les niveaux de VK et sphingolipides dans le cerveau, avec de potentiels effets néfastes sur les fonctions cérébrales.

Functional studies of the deubiquitinating enzymes USP19, USP4 and UCH-L1

El marcaje de proteínas con ubiquitina, conocido como ubiquitinación, cumple diferentes funciones que incluyen la regulación de varios procesos celulares, tales como: la degradación de proteínas por medio del proteosoma, la reparación del ADN, la señalización mediada por receptores de membrana, y la endocitosis, entre otras (1). Las moléculas de ubiquitina pueden ser removidas de sus sustratos gracias a la acción de un gran grupo de proteasas, llamadas enzimas deubiquitinizantes (DUBs) (2). Las DUBs son esenciales para la manutención de la homeostasis de la ubiquitina y para la regulación del estado de ubiquitinación de diferentes sustratos. El gran número y la diversidad de DUBs descritas refleja tanto su especificidad como su utilización para regular un amplio espectro de sustratos y vías celulares. Aunque muchas DUBs han sido estudiadas a profundidad, actualmente se desconocen los sustratos y las funciones biológicas de la mayoría de ellas. En este trabajo se investigaron las funciones de las DUBs: USP19, USP4 y UCH-L1. Utilizando varias técnicas de biología molecular y celular se encontró que: i) USP19 es regulada por las ubiquitin ligasas SIAH1 y SIAH2 ii) USP19 es importante para regular HIF-1α, un factor de transcripción clave en la respuesta celular a hipoxia, iii) USP4 interactúa con el proteosoma, iv) La quimera mCherry-UCH-L1 reproduce parcialmente los fenotipos que nuestro grupo ha descrito previamente al usar otros constructos de la misma enzima, y v) UCH-L1 promueve la internalización de la bacteria Yersinia pseudotuberculosis.

Role of spinal microglia in myositis-induced central sensitisation: An immunohistochemical and behavioural study in rats

There is increasing evidence that spinal glial cells play an important role in chronic pain states. However, so far no data on the role of microglia in muscle pain are available. The aim of the present study was to investigate the involvement of spinal microglial cells in chronic muscle pain. In a rat model of chronic muscle inflammation (injection of complete Freunds adjuvant into the gastrocnemius-soleus muscle) alterations of microglia were visualized with quantitative OX-42 immunohistochemistry in the dorsal horn of the segments L4 and L5 12 days after induction of inflammation. In behavioural experiments the influence of chronic intrathecally applied minocycline - a specific microglia inhibitor - or an antibody against tumour necrosis factor-alpha (TNF-alpha: a cytokine released from microglia) on pain-related behaviour was investigated after 1, 3, 6, and 12 days. The immunhistochemical data show that in the deep laminae of the spinal dorsal horn microglial cells reacted with morphological changes to the muscle inflammation. Following inflammation, the mean boundary length surrounding the OX-42 immunostained area was significantly shorter. This indicates that microglial cells were activated by the myositis and withdrew their processes. Chronic intrathecal administration of minocycline or anti TNF-alpha with an osmotic mini-pump largely normalised the inflammation-induced changes in spontaneous exploratory behaviour and attenuated the hypersensitivity to mechanical stimulation. Both the immunohistochemical and behavioural data show that spinal microglial cells are involved in nociceptive processes in the cause of a chronic muscle inflammation. (C) 2008 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

Social separation and diazepam withdrawal increase anxiety in the elevated plus-maze and serotonin turnover in the median raphe and hippocampus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

How wild bearded capuchin monkeys select stones and nuts to minimize the number of strikes per nut cracked

Wild bearded capuchin monkeys, Cebus libidinosus, use stone tools to crack palm nuts to obtain the kernel. In five experiments, we gave 10 monkeys from one wild group of bearded capuchins a choice of two nuts differing in resistance and size and/or two manufactured stones of the same shape, volume and composition but different mass. Monkeys consistently selected the nut that was easier to crack and the heavier stone. When choosing between two stones differing in mass by a ratio of 1.3:1, monkeys frequently touched the stones or tapped them with their fingers or with a nut. They showed these behaviours more frequently before making their first selection of a stone than afterward. These results suggest that capuchins discriminate between nuts and between stones, selecting materials that allow them to crack nuts with fewer strikes, and generate exploratory behaviours to discriminate stones of varying mass. In the final experiment, humans effectively discriminated the mass of stones using the same tapping and handling behaviours as capuchins. Capuchins explore objects in ways that allow them to perceive invariant properties (e.g. mass) of objects, enabling selection of objects for specific uses. We predict that species that use tools will generate behaviours that reveal invariant properties of objects such as mass; species that do not use tools are less likely to explore objects in this way. The precision with which individuals can judge invariant properties may differ considerably, and this also should predict prevalence of tool use across species. (C) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Coping personality type and environmental enrichment affect aggression at weaning in pigs

This study investigated the effects of different environmental treatments and personality types on aggression at mixing of newly weaned domestic piglets. From birth to weaning, 16 litters were housed with their dams in either barren (B) or larger, substrate-enriched (E) environments. At 15 days old, piglets were classified as 'high' (HR) or low resistant' (LR) in a manual restraint test (backtest), which is thought to identify proactive (HR) and reactive (LR) stress coping strategies that may reflect different personality types. At 30 days old, 128 piglets were weaned, relocated and mixed into 32 pens comprising two HR and two LR unfamiliar pigs, balanced for sex and weaning weight. Eight B and eight E groups changed environmental condition whereas the others remained in the same type of environment. Number and duration of fights. fight outcomes and unilateral fighting were scored for 5 h post-mixing and skin lesions were counted before and 5 h, 1 day and 2 days after mixing. On the day following weaning, fighting and also exploratory and oral manipulative behaviours were measured for 6 h. Generalized Linear Mixed Model analyses suggested interactions between pre-weaning environment, post-weaning environment and personality type. Overall, pre-weaning E pigs had longer fights at weaning and mixing (P=0.01) and fought for longer on the next day (P=0.02) than pre-weaning B pigs, and inflicted more skin lesions (P=0.02). Post-weaning enrichment did not affect fighting at mixing but reduced the time spent fighting the next day (P=0.03). Personality had subtle and environment-dependent effects on fighting, and influenced the "structure" rather than the amount of aggressive behaviour. HR pigs, for instance, bullied (i.e. chased surrendering pigs) more often (P=0.009) and their fighting behaviour was less affected by their relative body weight than that of LR pigs. Post-weaning E pigs showed relatively higher levels of exploratory behaviour (P=0.02) and less oral manipulative behaviour (P=0.04) than post-weaning B pigs. In particular, switching from a good quality environment (E) to a worse quality one (B) at weaning decreased exploratory behaviour on the next day, especially for LR pigs, who also tended to fight with and orally manipulate their pen mates more in that condition, and seemed to be more affected by a deterioration of the environment. Overall, pre-weaning enrichment increased aggression after weaning whereas post-weaning enrichment reduced it, and personality type related to some aspects of fighting behaviour. (C) 2011 Elsevier B.V. All rights reserved.