O objetivo geral deste estudo foi verificar os efeitos terapêuticos do enriquecimento ambiental e do exercício físico forçado sobre as conseqüências funcionais e cognitivas da Hipoperfusão Encefálica Crônica (HEC) em ratos Wistar. Além disso, padronizamos protocolo alternativo de HEC, a fim de aumentar a taxa de sobrevivência característica deste modelo, juntamente com a análise comportamental e imunohistoquímica do sétimo ao sexto mês após a cirugia, analisando o comportamento de neurônios e astrócitos no hipocampo. Os resultados mostraram que o protocolo modificado, ou seja, com a oclusão das carótidas realizadas com uma semana de intervalo, apresentam resultados comportamentais e morfológicos similares aos do protocolo padrão; todavia, a taxa de sobrevida dos animais no protocolo modificado é significativamente maior quando comparados ao padrão. Além disso, em ambos os protocolos, os animais hipoperfundidos apresentam um déficit cognitivo no Teste Water Maze três meses após a cirurgia, mas os grupos isquêmicos não apresentaram diferenças morfológicas quando comparados ao seus controles em relação a volume total Hipocampal e área Estriatal. Ao analisar o tempo pós- lesão do déficit cognitivo, verificamos que a HEC causa danos comportamentais a longo prazo, chegando a seis meses após o evento isquêmico. Enquanto a cognição é afetada na fase crônica, as células neuronais e astrogliais são acometidas nas fases mais agudas deste modelo, começando a aparecer morte neuronal (através da quantificação de NeuN) e astrogliose reativa (através da quantificação do imunoconteúdo de GFAP) já nos primeiros dias, permanecendo até aproximadamente 3 meses após a lesão. Após o dano estabelecido, testamos estratégias terapêuticas com o objetivo de amenizar principalmente o dano cognitivo apresentado pelos animais a partir dos três meses após cirurgia. Inicialmente foi analisado o efeito pré e pós - isquemia do exercício físico forçado através de uma esteira para ratos na memória espacial e de trabalho, através do Water Maze e bioquimicamente no estado oxidativo cerebral. Posteriormente, os mesmos parâmetros foram testados, só que com a intervenção do enriquecimnto ambiental tanto pré quanto pós-isquemia também. O modelo de hipoperfusão cerebral crônica causa como citado anteriormente, um déficit bastante importante na memória e no apredizado. Somado a isso, em relação ao estresse oxidativo, a quantidade de radicais livres e o estado de lipoperoxidação celular encontra-se bastante aumentados no hipocampo de animais submetidos a isquemia, assim como as enzimas antioxidantes. O protocolo de atividade física regular forçada (3 vezes por semana, durante 20 minutos num período de 3 meses), sobretudo nos grupos pré e pré+pós-isquemia, preveniu os efeitos cognitivos e bioquímicos da HEC. Tal reversão também ocorreu com o uso do enriquecimento ambiental realizado 3 vezes por semana, 1 hora durante 3 meses em todos os grupos estimulados. / The aim of this study was to verify the experimental therapeutic effects of environmental enrichment and forced physical exercise on the consequences of cognitive and functional chronic cerebral hypoperfusion (CCH) in Wistar rats. To do that, a CCH alternative protocol was standardized, in order to increase the survival rate of this model, together with the behavioral and immunohistochemistry analysis done up to the sixth month after the surgery, analyzing hippocampus neurons and astrocytes. Results showed that the modified protocol, with occlusion of both carotid arteries performed with a one-week interval, presents morphological and behavioral results similar to the standard protocol; however, the rate of survival after the modified protocol was significantly greater when compared to the standard one. In addition, both protocols produced ischemic animals with cognitive deficits in the Water Maze Task, three months after the surgery, however with no gross morphological lesion, as assessed by hippocampal volume and estriatal area. The cognitive deficit in CCH rats is long lasting, reaching six months after the ischemic event. While the cognition is affected in the chronic phase of hypoperfusion, the neuronal and astrogliais cells are affected in acute phases of this model; neuronal death (through quantification of NeuN) and reactive astrogliosis (through quantification of imunocontent of GFAP) are already present in the first days and remain until approximately 3 months after the lesion. We tested therapeutic strategies with the aim of alleviating mainly the cognitive damage presented by animals, as from three months after surgery. Initially, the effects of preand post-ischemia forced physical exercise in spatial and working memory, through the Water Maze Tak and oxidative stress parameters were analyzed. Subsequently, we tested the effects of environmental enrichment, both pre- and post-ischemia. The model of chronic cerebral hypoperfusion as previously mentioned, causes an important deficit in spatial learning and memory; the free radicals content and cellullar lipid peroxidation is also substantially increased in the hippocampus of animals submitted to hypoperfusion, as well as the antioxidant enzymes. Forced regular physical activity protocol (20-min, 3 times per week during 12 weeks – moderate), especially in groups pre and pre+post-ischemia, warned cognitive and biochemical preventive effects in CCH rats; the same occurred with the use of enrichment environmental performed 1- hr, 3 times per week during 12 weeks in all groups stimulated.

Ratos submetidos à desnutrição proteica apresentam elevada impulsividade e alterações em comportamentos de avaliação de risco no labirinto em cruz elevado (LCE). A desnutrição também pode influenciar a atividade do eixo hipotálamo-hipófise-adrenal (HPA). Alterações causadas pela desnutrição podem ser parcialmente revertidas pela estimulação ambiental; animais desnutridos e submetidos ao enriquecimento ambiental apresentaram maior locomoção e exploração no LCE, comparados com animais de mesma condição de dieta e que não foram estimulados. Demonstrou-se também que a estimulação pode influenciar os níveis de corticosterona plasmática evidenciando uma alteração da sensibilidade do eixo HPA. Este trabalho tem o objetivo de comparar, em ratos desnutridos (M) e bem nutridos (C), os efeitos do enriquecimento ambiental (E) em relação às concentrações de corticosterona plasmática, expressão de receptores de glicocorticóides (GR) no hipocampo e o desempenho no LCE aos 36 dias de idade. Ratos Wistar machos foram divididos em dois grupos de acordo com a dieta e subdivididos em subgrupos conforme a manipulação ambiental. A manipulação ambiental foi realizada no período de 8 a 35 dias (1 hora por dia). Após o teste no LCE os animais foram decapitados e tiveram o sangue coletado e o cérebro removido. Para a análise de corticosterona plasmática foi utilizada a técnica de radioimunoensaio. Para a quantificação dos receptores (GR) no hipocampo foi realizada uma análise quantitativa de expressão gênica por meio da reação em cadeia da polimerase (PCR) em tempo real. Ratos M apresentaram menor peso corporal quando comparados com os ratos C (p<0,001). Em relação ao LCE, ratos M permaneceram uma maior porcentagem de tempo [F(1,44)=9,08; p<0,01] e entraram mais [F(1,44)=9,01; p<0,01] nos braços abertos em relação a C. Animais ME apresentaram porcentagem de tempo nos braços abertos (6% ± 2%) próxima àquela dos animais CN (8% ± 2%). De acordo com a PCR em tempo real, o teste do LCE alterou a quantidade de receptores GR no hipocampo (t(10)=2,37; p<0,05) e essa adaptação ocorreu diferentemente em ratos M quando comparados com os C. Também foi possível observar que a quantidade de receptores GR após o teste do LCE é diferente entre os grupos M e ME (t(11)=4,48; p<0,05). Os dados do presente estudo sugerem que animais desnutridos se expõem a mais situações de risco que ratos bem nutridos. Quando o enriquecimento ambiental foi realizado no período crítico do desenvolvimento do sistema nervoso central observou-se um efeito de neuroproteção em relação às alterações produzidas pela desnutrição tanto na expressão de RNAm de receptores GR como no comportamento de avaliação de risco de ratos no LCE. Os dados do presente trabalho também mostraram que a desnutrição pode alterar a resposta de estresse mediada pelo eixo HPA após exposição ao teste do LCE, e que o enriquecimento ambiental possui efeito protetor em relação os efeitos da desnutrição precoce sobre a atividade deste eixo / Rats subjected to protein malnutrition have high impulsivity and changes in risk-assessment behaviors in the elevated plus maze (EPM). Malnutrition can also influence the activity of the hypothalamic-pituitary-adrenal (HPA). Changes caused by malnutrition can be partly reversed by environmental stimulation; malnourished animals subjected to environmental enrichment had higher locomotion and exploration in the EPM compared with animals of the same condition and diet that were not stimulated. It was also demonstrated that stimulation can influence plasma corticosterone levels indicating a change in sensitivity of the HPA axis. This study aims to compare, in undernourished rats (M) and well nourished (C), the effects of environmental enrichment (E) in relation to plasma concentrations of corticosterone, expression of glucocorticoid receptors (GR) in the hippocampus and performance in EPM at 36 days of age. Male Wistar rats were divided into two groups according to diet and subdivided according handling environment. The environmental manipulation was performed within 8 to 35 days (1 hour per day). After testing in the EPM animals were decapitated and had their blood drawn and the brain removed. For the analysis of plasma corticosterone it was used the radioimmunoassay technique. For quantification of the glucocorticoid receptor (GR) in the hippocampus it was performed a quantitative analysis of gene expression by polymerase chain reaction (PCR) in real time. M rats showed lower body weight compared to C rats (p<0.001). In relation to the EPM, M rats showed higher number of entries [F(1,44)=9.01, p<0.01] and remain a higher percentage of time [F(1,44)=9.08, p<0.01] in the open arms as compared to C. ME rats presented a percentage of time in the open arms (6% ± 2%) similar to that of CN animals (8% ± 2%). According to the real time PCR, the EPM test changed the quantity of GR receptors in the hippocampus (t(10)=2.37, p<0.05), and that adaptation was different in M as compared with C rats. It was also observed that the amount of GR after EPM test was different between M and ME groups (t(11)=4.48, p<0.05). Data from the present study suggest that M animals are more likely to explore risk situations than C rats. It is also suggested that environmental enrichment imposed during the critical period of central nervous system development may have neuroprotective effects in both physiological and behavioral changes produced by early protein malnutrition. The data of this work also showed that malnutrition may alter the stress response mediated by the HPA axis after exposure to the EPM test and that environmental enrichment has a protective effect against the effects of malnutrition on the functioning of that axis.

O objetivo geral deste estudo foi verificar os efeitos terapêuticos do enriquecimento ambiental e do exercício físico forçado sobre as conseqüências funcionais e cognitivas da Hipoperfusão Encefálica Crônica (HEC) em ratos Wistar. Além disso, padronizamos protocolo alternativo de HEC, a fim de aumentar a taxa de sobrevivência característica deste modelo, juntamente com a análise comportamental e imunohistoquímica do sétimo ao sexto mês após a cirugia, analisando o comportamento de neurônios e astrócitos no hipocampo. Os resultados mostraram que o protocolo modificado, ou seja, com a oclusão das carótidas realizadas com uma semana de intervalo, apresentam resultados comportamentais e morfológicos similares aos do protocolo padrão; todavia, a taxa de sobrevida dos animais no protocolo modificado é significativamente maior quando comparados ao padrão. Além disso, em ambos os protocolos, os animais hipoperfundidos apresentam um déficit cognitivo no Teste Water Maze três meses após a cirurgia, mas os grupos isquêmicos não apresentaram diferenças morfológicas quando comparados ao seus controles em relação a volume total Hipocampal e área Estriatal. Ao analisar o tempo pós- lesão do déficit cognitivo, verificamos que a HEC causa danos comportamentais a longo prazo, chegando a seis meses após o evento isquêmico. Enquanto a cognição é afetada na fase crônica, as células neuronais e astrogliais são acometidas nas fases mais agudas deste modelo, começando a aparecer morte neuronal (através da quantificação de NeuN) e astrogliose reativa (através da quantificação do imunoconteúdo de GFAP) já nos primeiros dias, permanecendo até aproximadamente 3 meses após a lesão. Após o dano estabelecido, testamos estratégias terapêuticas com o objetivo de amenizar principalmente o dano cognitivo apresentado pelos animais a partir dos três meses após cirurgia. Inicialmente foi analisado o efeito pré e pós - isquemia do exercício físico forçado através de uma esteira para ratos na memória espacial e de trabalho, através do Water Maze e bioquimicamente no estado oxidativo cerebral. Posteriormente, os mesmos parâmetros foram testados, só que com a intervenção do enriquecimnto ambiental tanto pré quanto pós-isquemia também. O modelo de hipoperfusão cerebral crônica causa como citado anteriormente, um déficit bastante importante na memória e no apredizado. Somado a isso, em relação ao estresse oxidativo, a quantidade de radicais livres e o estado de lipoperoxidação celular encontra-se bastante aumentados no hipocampo de animais submetidos a isquemia, assim como as enzimas antioxidantes. O protocolo de atividade física regular forçada (3 vezes por semana, durante 20 minutos num período de 3 meses), sobretudo nos grupos pré e pré+pós-isquemia, preveniu os efeitos cognitivos e bioquímicos da HEC. Tal reversão também ocorreu com o uso do enriquecimento ambiental realizado 3 vezes por semana, 1 hora durante 3 meses em todos os grupos estimulados. / The aim of this study was to verify the experimental therapeutic effects of environmental enrichment and forced physical exercise on the consequences of cognitive and functional chronic cerebral hypoperfusion (CCH) in Wistar rats. To do that, a CCH alternative protocol was standardized, in order to increase the survival rate of this model, together with the behavioral and immunohistochemistry analysis done up to the sixth month after the surgery, analyzing hippocampus neurons and astrocytes. Results showed that the modified protocol, with occlusion of both carotid arteries performed with a one-week interval, presents morphological and behavioral results similar to the standard protocol; however, the rate of survival after the modified protocol was significantly greater when compared to the standard one. In addition, both protocols produced ischemic animals with cognitive deficits in the Water Maze Task, three months after the surgery, however with no gross morphological lesion, as assessed by hippocampal volume and estriatal area. The cognitive deficit in CCH rats is long lasting, reaching six months after the ischemic event. While the cognition is affected in the chronic phase of hypoperfusion, the neuronal and astrogliais cells are affected in acute phases of this model; neuronal death (through quantification of NeuN) and reactive astrogliosis (through quantification of imunocontent of GFAP) are already present in the first days and remain until approximately 3 months after the lesion. We tested therapeutic strategies with the aim of alleviating mainly the cognitive damage presented by animals, as from three months after surgery. Initially, the effects of preand post-ischemia forced physical exercise in spatial and working memory, through the Water Maze Tak and oxidative stress parameters were analyzed. Subsequently, we tested the effects of environmental enrichment, both pre- and post-ischemia. The model of chronic cerebral hypoperfusion as previously mentioned, causes an important deficit in spatial learning and memory; the free radicals content and cellullar lipid peroxidation is also substantially increased in the hippocampus of animals submitted to hypoperfusion, as well as the antioxidant enzymes. Forced regular physical activity protocol (20-min, 3 times per week during 12 weeks – moderate), especially in groups pre and pre+post-ischemia, warned cognitive and biochemical preventive effects in CCH rats; the same occurred with the use of enrichment environmental performed 1- hr, 3 times per week during 12 weeks in all groups stimulated.

O objetivo geral deste estudo foi verificar os efeitos terapêuticos do enriquecimento ambiental e do exercício físico forçado sobre as conseqüências funcionais e cognitivas da Hipoperfusão Encefálica Crônica (HEC) em ratos Wistar. Além disso, padronizamos protocolo alternativo de HEC, a fim de aumentar a taxa de sobrevivência característica deste modelo, juntamente com a análise comportamental e imunohistoquímica do sétimo ao sexto mês após a cirugia, analisando o comportamento de neurônios e astrócitos no hipocampo. Os resultados mostraram que o protocolo modificado, ou seja, com a oclusão das carótidas realizadas com uma semana de intervalo, apresentam resultados comportamentais e morfológicos similares aos do protocolo padrão; todavia, a taxa de sobrevida dos animais no protocolo modificado é significativamente maior quando comparados ao padrão. Além disso, em ambos os protocolos, os animais hipoperfundidos apresentam um déficit cognitivo no Teste Water Maze três meses após a cirurgia, mas os grupos isquêmicos não apresentaram diferenças morfológicas quando comparados ao seus controles em relação a volume total Hipocampal e área Estriatal. Ao analisar o tempo pós- lesão do déficit cognitivo, verificamos que a HEC causa danos comportamentais a longo prazo, chegando a seis meses após o evento isquêmico. Enquanto a cognição é afetada na fase crônica, as células neuronais e astrogliais são acometidas nas fases mais agudas deste modelo, começando a aparecer morte neuronal (através da quantificação de NeuN) e astrogliose reativa (através da quantificação do imunoconteúdo de GFAP) já nos primeiros dias, permanecendo até aproximadamente 3 meses após a lesão. Após o dano estabelecido, testamos estratégias terapêuticas com o objetivo de amenizar principalmente o dano cognitivo apresentado pelos animais a partir dos três meses após cirurgia. Inicialmente foi analisado o efeito pré e pós - isquemia do exercício físico forçado através de uma esteira para ratos na memória espacial e de trabalho, através do Water Maze e bioquimicamente no estado oxidativo cerebral. Posteriormente, os mesmos parâmetros foram testados, só que com a intervenção do enriquecimnto ambiental tanto pré quanto pós-isquemia também. O modelo de hipoperfusão cerebral crônica causa como citado anteriormente, um déficit bastante importante na memória e no apredizado. Somado a isso, em relação ao estresse oxidativo, a quantidade de radicais livres e o estado de lipoperoxidação celular encontra-se bastante aumentados no hipocampo de animais submetidos a isquemia, assim como as enzimas antioxidantes. O protocolo de atividade física regular forçada (3 vezes por semana, durante 20 minutos num período de 3 meses), sobretudo nos grupos pré e pré+pós-isquemia, preveniu os efeitos cognitivos e bioquímicos da HEC. Tal reversão também ocorreu com o uso do enriquecimento ambiental realizado 3 vezes por semana, 1 hora durante 3 meses em todos os grupos estimulados. / The aim of this study was to verify the experimental therapeutic effects of environmental enrichment and forced physical exercise on the consequences of cognitive and functional chronic cerebral hypoperfusion (CCH) in Wistar rats. To do that, a CCH alternative protocol was standardized, in order to increase the survival rate of this model, together with the behavioral and immunohistochemistry analysis done up to the sixth month after the surgery, analyzing hippocampus neurons and astrocytes. Results showed that the modified protocol, with occlusion of both carotid arteries performed with a one-week interval, presents morphological and behavioral results similar to the standard protocol; however, the rate of survival after the modified protocol was significantly greater when compared to the standard one. In addition, both protocols produced ischemic animals with cognitive deficits in the Water Maze Task, three months after the surgery, however with no gross morphological lesion, as assessed by hippocampal volume and estriatal area. The cognitive deficit in CCH rats is long lasting, reaching six months after the ischemic event. While the cognition is affected in the chronic phase of hypoperfusion, the neuronal and astrogliais cells are affected in acute phases of this model; neuronal death (through quantification of NeuN) and reactive astrogliosis (through quantification of imunocontent of GFAP) are already present in the first days and remain until approximately 3 months after the lesion. We tested therapeutic strategies with the aim of alleviating mainly the cognitive damage presented by animals, as from three months after surgery. Initially, the effects of preand post-ischemia forced physical exercise in spatial and working memory, through the Water Maze Tak and oxidative stress parameters were analyzed. Subsequently, we tested the effects of environmental enrichment, both pre- and post-ischemia. The model of chronic cerebral hypoperfusion as previously mentioned, causes an important deficit in spatial learning and memory; the free radicals content and cellullar lipid peroxidation is also substantially increased in the hippocampus of animals submitted to hypoperfusion, as well as the antioxidant enzymes. Forced regular physical activity protocol (20-min, 3 times per week during 12 weeks – moderate), especially in groups pre and pre+post-ischemia, warned cognitive and biochemical preventive effects in CCH rats; the same occurred with the use of enrichment environmental performed 1- hr, 3 times per week during 12 weeks in all groups stimulated.

Cette thèse avait pour but d’étudier dans quelle mesure l’enrichissement des conditions d’hébergement jusqu’à- ou à partir d’-un âge auquel les déficits cognitifs sont déjà présents contribue au maintien de la mémoire spatiale observé chez des rats âgés hébergés toute leur vie en environnement enrichi (EE), et d’étudier certains mécanismes neurobiologiques susceptibles de contribuer à cette préservation. Nous avons montré que l’hébergement en EE n’a pas besoin d’être maintenu jusqu’à la fin de la vie pour permettre la préservation des fonctions cognitives chez le Rat âgé. De plus, un enrichissement tardif ne permet pas de récupérer des capacités déjà altérées mais permet la préservation de certaines fonctions d’altérations subséquentes. Ce maintien de la mémoire spatiale ne semble pas être dû à la modification par l’enrichissement du cycle veille-sommeil. Par contre, cet enrichissement induit une modification de l’activité oscillatoire hippocampique, et pourrait, en favorisant une synchronisation neuronale locale, promouvoir un traitement de l’information au sein de réseaux plus spécialisés. Enfin, l’exposition à un EE pendant toute la vie permet la préservation de l’innervation cholinergique de différentes aires cérébrales, un effet pouvant contribuer au maintien des fonctions cognitives chez les animaux âgés hébergés toute leur vie en EE. / This thesis aimed to investigate in which extent environmental enrichment (EE) until or from an age at which cognitive decline is already apparent contributes to the maintenance of spatial memory observed in aged rats housed all their life in EE, and to study some neurobiological mechanisms likely underlying this preservation. We showed that housing in EE does not need to be maintained until the end of life to allow the preservation of cognitive function in aged rats. Moreover, late EE does not permit the recovery from already altered capabilities, but enables the preservation of some functions of subsequent alterations. The maintenance of spatial memory does not seem to be due to EE-related modification of sleep-wake cycle. But, exposure to EE induces a modification of hippocampal oscillatory activity, and could, by supporting local neuronal synchronization, promote information processing in more specialized networks. Finally, EE preserves the cholinergic system from age-related alteration in different cerebral areas, a mechanism that could participate to the maintenance of cognitive function in aged rats housed all their life in EE.

Patients with epilepsy often suffer debilitating cognitive and psycho-affective disorders.In some cases, epilepsy is associated to neurodegenerative processes that are the targetof certain therapeutical agents. Today, erythropoietin is considered as one of the most promising neuroprotective agents. In addition, an increased body of studies provides evidence that enrichment (or complexity) of housing decreases the cerebral vulnerabilityin the context of diverse brain insults. In this thesis, we demonstrate: 1) in a model ofepilepsy with large neuronal lesions, that erythropoietin protects the most vulnerable neuronal populations to excitotoxic injury, at the only condition that neuronal expression of its receptor is optimized prior to the primary insult causing epilepsy; 2) in a model of epilepsy associated with faint neuronal lesions that: i) erythropoietin prevents anxietyand impaired spatial learning and memory, ii) enriched housing in Marlau™ cages is moreefficient than erythropoietin, and iii) erythropoietin treatment abolishes beneficial effectsof enriched housing. These results, obtained in animal models of epilepsies associatedwith cognitive disorders establish that beneficial effects of a potential therapeutic agentmay rely on quality of life / Dans de nombreux cas, les patients avec des épilepsies présentent d’importants troubles cognitifs et psycho-affectifs. Ces épilepsies sont parfois accompagnées de phénomènes neuro-dégénératifs qui sont la cible de certains agents thérapeutiques. Aujourd’hui, l’érythropoïétine apparaît comme l’un des agents neuro-protecteurs les plus prometteurs.En outre, des études de plus en plus nombreuses montrent que l’enrichissement (ou la complexification) des conditions d’hébergement diminue la vulnérabilité cérébrale face à des agressions d’origine différente. Dans cette thèse, nous montrons : 1) dans un modèle d’épilepsie accompagné de vastes lésions neuronales, que l’érythropoïétine protège les populations neuronales les plus vulnérables aux atteintes excitotoxiques, à la condition d’optimiser l’expression neuronale de son récepteur, préalablement à l’agression cérébrale ayant initié l’épilepsie ; 2) dans un modèle d’épilepsie associé à des phénomènes neurodégénératifs très discrets, que : i) l’érythropoïétine bloque le développement de l’anxiété et des troubles de l’apprentissage et de la mémoire spatiale,ii) l’enrichissement du milieu d’hébergement en cages Marlau™ est plus efficace que l’érythropoïétine, et iii) le traitement par l’érythropoïétine annihile les effets bénéfiques de l’enrichissement du milieu d’hébergement. Les résultats de cette thèse, obtenus dans des modèles expérimentaux d’épilepsies associés à des troubles cognitifs, démontrent que les effets bénéfiques d’un potentiel agent thérapeutique peuvent dépendre de la qualité de vie

No description available.

No description available.

By studying how captive animals use outdoor space, we can determine which areas fulfill their biological and behavioral needs to improve enclosure design for animal welfare and visitor experience. The aim of the study was to determine the differential use of outdoor space in a mixed exhibit of captive ring-tailed lemurs (Lemur catta) and red ruffed lemurs (Varecia rubra), and to assess both the effect of adding environmental enrichment and possible visitor and meteorological effects on the lemurs’ use of space and behavior. For one month, five-minute interval scan sampling was used to record lemur location and behavior, as well as the meteorological conditions and presence of zoo visitors in the lemurs’ outdoor enclosure. That baseline was followed by four alternating two-week periods of food or structural enrichment, both with and without visitors. Enrichment increased the lemurs’ use of the enriched sectors, decreased resting, and increased locomotion. Structural enrichment increased their exploratory behaviors and stimulated arboreal locomotion. Both species preferred sunny and warm conditions for sunbathing and resting, while moving more around the enclosure in cooler and cloudier weather. The visitor effect on the lemurs’ use of space was weaker than the effects of enrichment and meteorological conditions. The availability of areas to hide and possible habituation to humans may have played a role in the reduced visitor effect. The results of the study showed inter-specific differences in the lemurs’ use of space and behavior and a complex combined effect of enrichment, visitor presence and meteorological conditions.

African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate. Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS. In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved. Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence. Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so. This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management.