Host-parasite interactions are complex, involving host behaviour, host condition, and possible antagonism or mutualism between co-occurring parasites. The white-footed mouse (Peromyscus leucopus) is a small, abundant, generalist rodent, and the primary host for the black-legged tick (Ixodes scapularis) in its larval stage. Since larval ticks do not actively pursue their hosts (they wait for possible hosts to come to them), individual differences in mouse exploratory behaviour might be expected to correlate with tick burden. However, mice may also prevent tick attachment with defensive behaviour such as grooming. Yet, the relationships between tick parasitism and host exploratory and grooming behaviours have never been assessed. I analysed data from a capture-mark-recapture study conducted over 5 summers (2016-2020) in eastern Ontario, Canada, in which 1,035 mice were captured a total of 4,333 times. The probability of tick parasitism occurring and being more intense was significantly higher when the mouse was also parasitized by fleas, suggesting co-occurrence of these two parasites on host mice. A total of 510 mice were subjected to an open-field test to quantify exploratory and grooming behaviours. Exploration had a negative relationship with tick presence and a positive relation with flea presence. Most interestingly, there was a significant “tick × flea” interaction on exploratory behaviour such that fleas were positively associated with exploration only when ticks were absent. Surprisingly, there was no relationship between grooming behaviour in the open-field test and parasite presence, although grooming increased with mouse activity. This study shows that co-occurring parasite species (ticks and fleas) may interact to affect their host’s exploratory behaviour. Alternatively, individual differences in exploratory behaviour of hosts may differentially affect their susceptibility to being infested with ticks, fleas, or both. Future manipulative studies should use experimental design to determine the causality of the parasitism-behaviour relationships observed.

Personality, or behavioural differences among individuals, which are stable both in time and across contexts, is a highly popular topic. Currently there has been an increase of interest in the relationship between personality and repeatability, which is a methodical approach developed to measure the stability of interindividual differences in time. The aim of this thesis is to evaluate the personality of rats according to behavioural patterns exhibited under widely used testing procedures in new environment (open field test, hole board test) and to compare, how behavioural traits in these tests mutually correlate and change over time. Each test trial was repeated eight times with different intervals (24 hours, 6 days, 4 weeks). The results suggest that most of the recorded behavioural variability can be explained with three principal axes. The first one is associated with loco-exploratory activity of the subject. The elements of behaviour associated with this axis are the most repeatable. The second axis is mostly associated with time the animal spent in the central part of the arena and the third axis represents the interest in holes in hole board test. These two axes are less repeatable. A significant effect of the identity of the animal was found in all behavioural traits, associated with these...

Early reports of enhanced behavioral reactivity in isolation-reared rats attributed this syndrome to "isolation stress." In the studies reported here, this "isolation stress syndrome" was reliably obtained in adult rats reared from weaning in individual hanging metal cages. Such isolates showed behavioral and adrenocortical symptoms of profound fear during open-field testing, unlike group-housed controls or littermate isolates reared singly in plastic cages. Animals in hanging metal cages are never touched by human caretakers, whereas rats reared in plastic cages are picked up and put in clean cages twice weekly. Handling hanging-cage isolates twice weekly to model the handling associated with cage changes completely protected against this syndrome. Further, there was no hormonal, neurochemical or anatomical evidence of chronic stress even in hanging-cage isolates. Littermates housed in social groupings (three rats per plastic cage) also froze and defecated in the open field at rates comparable to hanging-cage isolates if they were the first animals to be tested from their social group cage. It is probable that odor cues from familiar cagemates in the open field protected socially reared animals tested subsequently from the same cage from this syndrome. It is concluded that isolates are not chronically stressed, and that rearing effects are the result of a complex interaction between prior handling, social experience and test conditions.

京都大学 / 新制・課程博士 / 博士(薬科学) / 甲第23831号 / 薬科博第146号 / 新制||薬科||16(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 山下 富義, 教授 髙倉 喜信, 准教授 伊藤 美千穂 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

Systena frontalis (F.) (Coleoptera: Chrysomelidae), the red headed flea beetle (RHFB), is a ubiquitous pest of ornamental nursery crops in the eastern United States. Defoliation by adults renders plants unsaleable. Control costs and economic losses from injured plants have become a top concern among Virginia nurseries in the past decade. Current management tactics include spraying insecticides up to three times a week during the adult active season. The frequent use of insecticides poses a risk to the environment, non-target organisms, and evolution of resistance within the targeted beetle population. To develop a sustainable pest management program, more information is needed to understand pest biology, quantify the injury potential, and explore control tactics. Methods to monitor this beetle were used to observe peak activity throughout the growing season as well as the adult daily activity levels. There were three observed generations with population peaks in late June, late July, and late August into early September. Within the scale of one day, adult beetles were found to be diurnal with peaks in activity in the middle of the day. These findings will inform growers of the most efficient times to scout and spray, ultimately reducing insecticide usage. Quantification of feeding damage to individual leaves, the entire plant, and preference between older and newer growth may relate plant injury with specific population densities. The use of phenyl ethyl alcohol as an attractant lure, was explored to bolster pest control. Finally, insecticide bioassays were performed to compare those currently used to others yet untested. / Master of Science in Life Sciences / The red headed flea beetle (RHFB) is an important pest of ornamental crops in open-field nurseries along the Eastern United States. Defoliation caused by adult feeding renders plants unsellable. Japanese hollies, hydrangeas, and sweetspire iteas are among the most affected plants. Infested nurseries suffer severe economic losses due to insecticide costs and plant inventory reductions. Growers are spraying insecticides up to three times a week to manage RHFB. Frequent use of insecticides poses risks to the environment non-target organisms. This study will help improve control tactics for this pest and potentially minimize non-target effects by reducing insecticide usage. Understanding when beetles are active throughout the day, and throughout the growing season, may inform timing of scouting and insecticide sprays to maximize effectiveness. With populations highest in late June, late July, and late August, RHFB is estimated to have three generations per year. Adults are most active in the middle of the day and sedentary at night. It was observed how different densities of beetles cause injury to individual leaves and entire plants, and compared feeding preference on older versus newer growth. Chemical control tactics were explored including insecticides labeled and not labeled for RHFB such as iscycloseram. Finally, the effectiveness of phenyl ethyl alcohol as an attractant lure for RHFB was assessed and found ineffective within the open-field nursery ecosystem.

La paralysie cérébrale (PC) regroupe un ensemble varié de troubles moteurs, sensoriels et cognitifs, liés à des lésions de la substance blanche (i.e. leucomalacie périventriculaire, PVL) survenant, le plus souvent, après un épisode hypoxo-ischémique autour de la naissance. Afin de reproduire la PVL chez l'animal, nous utilisons une ischémie prénatale (PI) qui induit des lésions des substances blanche et grise. Les rats ischémiés développent des déficits cognitifs visuo-spatiaux et une hyperactivité, également observés chez les patients atteints de PC, liés à des lésions du cortex entorhinal, préfrontal et cingulaire. La PI n'induit que des troubles locomoteurs modérés associés à des signes de spasticité, et une atteinte anatomique et fonctionnelle du cortex somesthésique primaire (S1), tandis que le cortex moteur (M1) reste intact. Ainsi, la PI reproduit les symptômes observés chez les enfants et adultes nés prématurément. La présence de mouvements spontanés anormaux au cours de la 1ère année conduisant à la PC suggère une implication de l'expérience sensorimotrice anormale dans le développement de cette pathologie. La combinaison d'une restriction sensorimotrice (SMR) durant le développement et de la PI induit des troubles cognitifs atténués mais une hyperactivité importante. Les rats combinant PI et SMR présentent des déficits posturo-moteurs drastiques et une spasticité, associés à une dégradation des tissus musculo-squelettiques, comparables à ceux observés chez les patients. Ces troubles moteurs, associés à une désorganisation importante des cartes corticales dans S1 et M1, suggèrent un dysfonctionnement important des boucles d'intégration sensorimotrice. / Cerebral palsy (CP) corresponds to various motor, sensory and cognitive disorders related to white matter damage (i.e. periventricular leucomalacia, PVL) often occurring after perinatal hypoxic-ischemic events. To reproduce PVL in rodents, we used a prenatal ischemia (PI) that induces white and gray matter damage. The ischemic rats exhibit visual-spatial cognitive deficits and hyperactivity, as observed in patients with CP, related to lesions of entorhinal, prefrontal and cingular cortices. Only mild locomotor disorders are induced by PI, associated to signs of spasticity, along with anatomical and functional degradation in the primary somatosensory cortex (S1), while the primary motor cortex (M1) remains unchanged. Thus, PI recapitulates the main symptoms found in children born preterm. Abnormal spontaneous movements (i.e. general movements) observed in infants who develop CP later on suggest that abnormal sensorimotor experience during maturation is key in the development of this catastrophic disease. The combination of a sensorimotor restriction (SMR) and PI in animal induces fewer cognitive deficits but still hyperactivity. Such a combination leads to severe postural and motor disorders, and spasticity, associated with musculoskeletal pathologies, as observed in patients with CP. In addition to motor disorders, drastic topographical disorganization of cortical maps in S1 and M1 suggest a major dysfunction of sensorimotor loops.

Ökad kunskap om djurs beteendesyndrom kan möjliggöra förbättrade bevarandeåtgärder för hotade arter. I den här studien genomgick 108 blankålar (Anguilla anguilla) två beteendetester; “open-field test” och “novel-object test”. Ålars morfologi och val av föda, habitat och dygnsaktivitet har i tidigare studier visats hänga ihop. I den här studien undersökte jag om det fanns något samband mellan ålarnas morfologi, aktivitet samt respons på främmande föremål. De ålar som var mest aktiva under open-field-testet var också de ålar som visade störst intresse för det främmande föremålet i novel-object-testet. Det fanns dock inte något samband mellan morfologi och aktivitet eller mellan morfologi och respons på främmande föremål. Detta innebär att ett utforskande och djärvt beteendesyndrom har upptäckts hos vissa av ålarna, medan den bakomliggande faktorn fortsätter vara okänd. / Increased knowledge of behavioural syndromes may contribute to enhancing our conservation methods for endangered species. In this study, the behavior of 108 silver eels (Anguilla anguilla) was assessed in two assays: an open-field test and a novel-object test. Eel morphology and diel activity as well as diet and habitat use have previously been shown to correlate with each other. In this study, I investigated the potential relationship between the morphology, activity and response to a novel object. The most active eels during the open-field test were also the ones that expressed the most interest for the novel object. There was, however, no correlation between morphology and activity or morphology and response to the novel object. This means an exploring and bold behaviour syndrome was discovered amongst some of the eels, whilst the underlying cause remains unknown.

The term "personality" nowadays occurs more often not only in psychological studies of humans but also in animal studies. Studying of personality help us to define the behavioural characteristics which can vary within the age, sexes, species or enviroments. Behavioral experiments are used to detect these behavioral patterns and they can divide the animals into the different groups. The subject of our research became three populations of house mouse (Mus musculus sensu lato) which we tested in a series of experiments involving free exploration, forced exploration, hole- board test, test of vertical activity and Elevated plus-maze. These experiments should reveal wheter the mice differ in their behaviour through the context of sex, comensalism or subspecies. We found (with in excepcion of one test) that intrapopulation variability differences are very small but interpopulation differences purely increase in the cas of comensalism and effects of subspecies. Keywords: Mus musculus, comensalism, open fieldtest, Elevated plus-maze, Principal Component Analysis (PCA)

Vários estudos realizados com roedores permitem analisar, entre outros fatores, as respostas dos animais à novidade, a emocionalidade e locomoção dos animais. Para tal, vários testes tem sido empregados e um dos mais utilizados é o do campo aberto. O presente estudo visa analisar o papel da presença de um animal adulto da mesma espécie, ou de espécie diferente, no comportamento exploratório e na ocupação das áreas de um campo aberto por filhotes de rato, testados em duas condições: agrupados ou individualmente. Na primeira condição os testes de exploração foram feitos em um campo aberto. Em uma das paredes do campo aberto foi acoplada uma gaiola que em diferentes momentos continha uma fêmea da mesma espécie (Rattus norvegicus), um macho da mesma espécie (ambos não familiarizados com os filhotes), a própria ama-de-leite ou uma fêmea de outra espécie, no caso, uma cobaia (Cavia porcelus). As sessões experimentais foram realizadas no vigésimo quinto dia de vida dos filhotes. Os animais foram divididos em cinco ninhadas compostas por oito filhotes cada uma: quatro machos e quatro fêmeas., testados juntos em uma única sessão. O primeiro grupo foi testado no campo aberto sem qualquer tipo de estímulo na gaiola. Os outros grupos foram testados, respectivamente, na presença da ama-de-leite, de uma outra rata, de um rato macho ou de uma cobaia. Na segunda condição, os sujeitos de outras cinco ninhadas foram testados nas mesmas circunstâncias, porém individualmente. Os resultados mostraram que a presença de um animal adulto altera a preferência pela ocupação dos cantos mais estruturados por filhotes de rato em campo aberto. Quando o adulto presente é um co-especifico, a tendência dos filhotes é de se aproximar do local onde o animal se encontra (gaiola). Na presença de um animal de outra espécie, a tendência é, num primeiro momento, de aproximação e posteriormente de permanência nos locais mais estruturados do campo aberto, como as áreas de duas paredes, igual aos testados com a gaiola vazia. Os animais apresentaram diferenças de comportamento devidos ao agrupamento. Os filhotes agrupados frequentaram mais a periferia do campo aberto e passaram mais tempo nestas áreas que os testados individualmente, que por sua vez tendem a se aproximar mais do adulto do que os testados em grupo. Na idade em que foram testadas, as fêmeas mostraram-se menos ansiosas que os machos. De um modo geral, a principal conclusão é a de que filhotes de rato expostos a um campo aberto na presença de um adulto, exibem preferência pelas proximidades do adulto quando este é um co-específico, tendendo a permanecer nas áreas mais estruturadas quando o animal presente é de outra espécie. / Several studies with rodents allow us to analyze, among other factors, the responses of animals to novelty, emotionality and locomotion of animals. For this, several tests have been used and one of the most frequently used is the open-field. The present study aims at examining the role of the presence of an adult animal of the same species, or of a different species, in the exploratory behavior and the occupation of areas of an open-field by rat pups, tested in two conditions: grouped and individually. In the first condition, exploration tests were done in an open-field. In one wall of the open-field a cage was connected which, in different occasions, contained a female of the same species (Rattus norvegicus), a male of the same species (both unfamiliar to the pups), the dam or a female of another species, in this case, a guinea-pig (Cavia porcelus). The experimental sessions occurred at the twenty-fifth day of life of the of pups. The animals were divided into five eight-pup litters with four males and four females, which were tested together in a single session. The first group was tested in the open-field without any kind of stimulus in the cage. The other groups were tested, respectively, in the presence of the dam, another female, a male or a female guinea-pig. In the second condition, all subjects in a litter were tested under the same circumstances, but individually. The results showed that the presence of an adult animal changes the preference for the occupation of the more structured corners by rat pups in the open-field. When the animal in the cage was an adult co-specific, the tendency of the subjects was to approach the place where the adult animal was (the cage). In the presence of an animal of another species, the trend was, at first, to approach and subsequently to spent more time in the most structured corners of the open-field, areas with two walls. The animals showed behavioral differences due to grouping. The grouped pups went more often to the periphery of the open-field and spent more time in these areas than those tested individually, which, in turn, tended to be close to the adult longer than the grouped subjects. At the age they were tested, female infants were less anxious than males. In general, the main conclusion is that rat pups exposed to an open-field in the presence of an adult, exhibit a preference for the vicinity of the adult when it is a co-specific, tending to remain in the more structured areas when the cage was empty or when the animal in the cage belonged to another species.

Les relations entre le stress et l'alimentation sont l'objet d'interactions complexes et multiples. Le lien habituellement admis entre le stress et le gain de poids passe par une modification du comportement alimentaire. Plusieurs travaux indiquant l'impact du stress sur la prise alimentaire ont donné cependant des résultats variables, engendrant selon les sujets une réduction ou un accroissement de la prise alimentaire sans préciser quel(s) est (sont) le(s) macronutriment(s) modifié(s). Dans la première partie de cette thèse nous avons montré l'influence du stress sur le gain de poids et sur le choix en macronutriments, étude réalisée sur le modèle rat soumis à deux situations alimentaires différentes (expérience 1 : les rats ont reçu l'aliment ad-lib ; expérience 2 : les rats sont soumis à une restriction alimentaire( 2 épisodes alimentaires par jour)). Les résultats de ces deux protocoles expérimentaux ont montré qu'un stress aigu (15 min de nage par jour pendant 3 jours consécutifs) appliqué juste avant la phase active entraîne une diminution du gain de poids journalier chez les rats Wistar mâles et femelles. Les mesures de consommations examinées à différents intervalles de temps durant la phase nocturne ont révélé une dépression de la prise alimentaire durant les 3 premières heures après le stress (expérience 1) et durant la 1ere période alimentaire (expérience 2) quel que soit le sexe. Le stress a entraîné aussi une augmentation de la corticostéronémie et une diminution de l'insulinémie. Ces résultats démontrent un dimorphisme sexuel quant au choix en macronutriments en réponse au stress. On conclue donc que les stress induit, en plus d'un effet quantitatif, des effets qualitatifs sur la prise alimentaire. Dans la deuxième partie nous nous sommes intéressés à la variabilité génétique de l'axe corticotrope en relation avec la régulation du métabolisme énergétique entre deux souches consanguines de rats : Fischer F344 obèse et Lou maigre. Les comparaisons neuroendocrinienne, nutritionnelle et métabolique ont révélé que la souche F344 présentait (i) des perturbations de son axe corticotrope qui se traduisent par une forte sécrétion de corticostérone et (ii) une forte vulnérabilité à développer l'obésité liée au régime par augmentation de l'adiposité et diminution du métabolisme de base comparée à la souche Lou. Dans la dernière partie de cette thèse nous avons utilisé une « approche nutraceutique » : testant l'influence, sur le stress, d'un aliment fonctionnel (extrait de levure). A partir de notre modèle de stress mis au point dans la première partie, nous avons pu montrer les propriétés protectrices de l'apport alimentaire de l'extrait de levure sur les perturbations comportementales et alimentaires induites par le stress. Ces résultats ouvrent une perspective sur la relation entre le stress et le comportement alimentaire mais aussi sur une meilleure compréhension de la résistance à l'obésité chez le rat Lou impliquant l'axe corticotrope.