The purpose of the present study was to determine olfactory detection thresholds in human subjects for a set of six sulfur-containing odorants which are known to be components of mammalian predator odors. Using a threealternative ascending staircase procedure, the olfactory sensitivity of 12 healthy adult human subjects, 6 males and 6 females was assessed with 2-propylthietane, 2,2-dimethylthietane, 3-mercapto-3-methylbutan-1-ol, 3-mercapto-3- methylbutyl formate, 3-methyl-1-butanethiol, and methyl-2-phenylethyl sulfide. The results showed that A) all six predator odorants were detected at concentrations below 1 ppb (parts per billion), and one of them (3-mercapto-3-methylbutyl formate) even at a concentration below 1 ppt (parts per trillion), B) structurally similar odorants yielded significantly different threshold values, and C) no significant sex differences were found in olfactory sensitivity with any of the six odorants. The findings obtained from the present study show that human subjects were not generally less sensitive to the predator odorants tested here compared to spider monkeys despite having a markedly lower number of olfactory receptor types. Further, they suggest that humans may be more sensitive to predator odorants compared to a variety of non-predator odorants. One possible explanation for the high olfactory sensitivity observed here is the fact that sulfur compounds typically can be detected at low concentrations. An alternative explanation derives from an evolutionary perspective as our human ancestors were a potential prey of large carnivores and  thus a high olfactory sensitivity for predator odors should be adaptive for humans.

The detection of predators by prey species is crucial in order to escape the threat posed by a predator. In mammals, the olfactory sensory system is commonly used to detect odors emitted by predators, and to determine how threatening the situation actually is. However, knowledge about this ability is still sparse and in some cases conflicting. The aim of the present study was therefore to assess whether CD-1 mice (Mus musculus) show behaviors such as avoidance, anxiety and/or decreased activity when exposed to any of the three odorants: cat bladder urine, horse voided urine or a fruity odor (N-pentyl acetate), with a blank solvent as an alternative in a two-compartment test arena. I found no significant differences between avoidance (the time that the mice spent in the different compartments), anxiety (the numbers of fecal pellets dropped by the mice), or the overall activity (the number of switches between the two compartments), when the mice were exposed to the three different odors. The fact that the cat urine derived from the bladder of the cat may explain the lack of avoidance responses, since bladder urine might not contain the same chemical components as voided urine. Bladder urine might therefore also lack the chemical components that signal “predator” to the mice. In conclusion, mice do not respond differently to the odor of cat bladder urine than to horse voided urine or to the fruity odor of N-pentyl acetate.

No description available.

No description available.

Thesis (M.S.)--Miami University, Dept. of Zoology, 2005. / Title from first page of PDF document. Includes bibliographical references (p. 31-35).

No description available.

Esse estudo foi realizado para verificar se a exposição a separações repetidas (por diferentes intervalos de tempo) de mães dos seus filhotes no período neonatal poderiam ser classificadas como indutoras de um estado do tipo deprimido em genitoras. Sessenta ratas Wistar prenhes foram divididas em 3 grupos: controle, separação por 10 minutos e separação por 3 horas. As intervenções neonatais foram realizadas nos dias 1-10 pós parto. Após o desmame as genitoras foram submetidas ao teste do nado forçado, ao teste do labirinto em cruz elevado e ao teste do odor de predador. Também foi avaliado o comportamento alimentar e os padrões de reatividade a um sabor doce e a um sabor amargo. Foi medido os níveis de ocitocina no líquido cefaloraquidiano, corticosterona plasmática e atividade hipocampal Na+, K+-ATPase, assim como a atividade das enzimas antioxidantes catalase, glutationa peroxidase, superoxido dismutase, produção de radicais livres, e a produção de óxido nítrico, além dos níveis dos receptores A2A de adenosina e D2 de dopamina no estriado dorsoventral e no hipocampo. Foi observado que somente a separação por 3 h induziu um aumento significativo no tempo de imobilidade no teste do nado forçado, o que é consistente com estudos prévios. A atividade hipocampal da Na+, K+-ATPase se mostrou diminuída no grupo separado por 10 minutos e mais significativamente diminuída nas genitoras submetidas a separação por 3 horas de seus filhotes. Adicionalmente, os níveis de ocitocina no líquido cefaloraquidiano se encontravam aumentados no grupo separado por 10 minutos, o que pode estar relacionado a um aumento no cuidado materno, induzido por esta manipulação dos filhotes, por parte das genitoras, como reportado na literatura. Uma redução nos níveis de óxido nítrico no hipocampo das genitoras separadas por 3 horas foi observado Nessas genitoras também foi verificado um aumento no comportamento de risco, uma diminuição no sentimento prazeroso frente a uma solução doce e aumento na sensibilidade a uma solução aversiva, o que é congruente a um perfil de estado do tipo deprimido. Além disso, nós verificamos uma diminuição na quantidade do receptor de dopamina D2 no estriado das mães submetidas a separação por 3 horas dos filhotes, o que poderia ser relacionado com uma diminuição no prazer (anedonia) que acontece na depressão. Conclui-se que a retirada dos filhotes das mães por longos períodos tornam essas mães mais susceptíveis ao desenvolvimento de características depressivas. / This study was carried out to ascertain whether exposure to repeated separations (different times) of mothers from their pups in the neonatal period could be classified as an induction of a depressive-like state in dams. Sixty Wistar rats were divided into 3 groups: control, brief separation and long-term separation. The neonatal interventions were done on postpartum days 1-10. After weaning, the dams were subjected to the forced swimming test, elevated plus maze and predator odor test. It was also evaluated the feeding behavior and the taste reactivity patterns to a sweet and to a bitter solution. It was mesaured cerebral spinal fluid oxytocin, plasma corticosterone, and hippocampal Na+, K+-ATPase activity, as well as the activity of the antioxidant enzymes catalase, glutathione peroxidase, superoxide dismutase, free radicals production, and the production of nitric oxide and the levels of adenosine A2A and dopamine D2 receptors in the dorsoventral striatum and hippocampus. It was observed that only the 3 h separation induced a significant increase in the immobility time of rats in the forced swimming test, which is consistent with previous studies. Hippocampal Na+, K+-ATPase activity was decreased in the brief separated group and more significantly decreased in dams subjected to 3h separation from their pups. Additionally, cerebral spinal fluid oxytocin was increased in dams of the brief separated group, which may be related to the increased handled-induced maternal care, as reported in the literature. A reduction in nitric oxide levels in the hippocampus in dams of the long separated group was also observed. It was also verify an increase in the risk-taking behavior by the 3h separated mothers. The 3h separated mother also demonstrated a diminished feeling of pleasure with a sucrose solution and a increased sensibility to a aversive solution, wich is congruent with a depressive like state profile. Furthermore, we shown a decrease in the dopamine D2 receptor quantity in the striatum of the 3 h separated mothers, wich could be related to a decrease in pleasure feeling (anhedonia) experienced in depression. It is concluded that the withdrawal of pups from their mothers for long periods make the mothers more susceptible to the development of depressive features.

Esse estudo foi realizado para verificar se a exposição a separações repetidas (por diferentes intervalos de tempo) de mães dos seus filhotes no período neonatal poderiam ser classificadas como indutoras de um estado do tipo deprimido em genitoras. Sessenta ratas Wistar prenhes foram divididas em 3 grupos: controle, separação por 10 minutos e separação por 3 horas. As intervenções neonatais foram realizadas nos dias 1-10 pós parto. Após o desmame as genitoras foram submetidas ao teste do nado forçado, ao teste do labirinto em cruz elevado e ao teste do odor de predador. Também foi avaliado o comportamento alimentar e os padrões de reatividade a um sabor doce e a um sabor amargo. Foi medido os níveis de ocitocina no líquido cefaloraquidiano, corticosterona plasmática e atividade hipocampal Na+, K+-ATPase, assim como a atividade das enzimas antioxidantes catalase, glutationa peroxidase, superoxido dismutase, produção de radicais livres, e a produção de óxido nítrico, além dos níveis dos receptores A2A de adenosina e D2 de dopamina no estriado dorsoventral e no hipocampo. Foi observado que somente a separação por 3 h induziu um aumento significativo no tempo de imobilidade no teste do nado forçado, o que é consistente com estudos prévios. A atividade hipocampal da Na+, K+-ATPase se mostrou diminuída no grupo separado por 10 minutos e mais significativamente diminuída nas genitoras submetidas a separação por 3 horas de seus filhotes. Adicionalmente, os níveis de ocitocina no líquido cefaloraquidiano se encontravam aumentados no grupo separado por 10 minutos, o que pode estar relacionado a um aumento no cuidado materno, induzido por esta manipulação dos filhotes, por parte das genitoras, como reportado na literatura. Uma redução nos níveis de óxido nítrico no hipocampo das genitoras separadas por 3 horas foi observado Nessas genitoras também foi verificado um aumento no comportamento de risco, uma diminuição no sentimento prazeroso frente a uma solução doce e aumento na sensibilidade a uma solução aversiva, o que é congruente a um perfil de estado do tipo deprimido. Além disso, nós verificamos uma diminuição na quantidade do receptor de dopamina D2 no estriado das mães submetidas a separação por 3 horas dos filhotes, o que poderia ser relacionado com uma diminuição no prazer (anedonia) que acontece na depressão. Conclui-se que a retirada dos filhotes das mães por longos períodos tornam essas mães mais susceptíveis ao desenvolvimento de características depressivas. / This study was carried out to ascertain whether exposure to repeated separations (different times) of mothers from their pups in the neonatal period could be classified as an induction of a depressive-like state in dams. Sixty Wistar rats were divided into 3 groups: control, brief separation and long-term separation. The neonatal interventions were done on postpartum days 1-10. After weaning, the dams were subjected to the forced swimming test, elevated plus maze and predator odor test. It was also evaluated the feeding behavior and the taste reactivity patterns to a sweet and to a bitter solution. It was mesaured cerebral spinal fluid oxytocin, plasma corticosterone, and hippocampal Na+, K+-ATPase activity, as well as the activity of the antioxidant enzymes catalase, glutathione peroxidase, superoxide dismutase, free radicals production, and the production of nitric oxide and the levels of adenosine A2A and dopamine D2 receptors in the dorsoventral striatum and hippocampus. It was observed that only the 3 h separation induced a significant increase in the immobility time of rats in the forced swimming test, which is consistent with previous studies. Hippocampal Na+, K+-ATPase activity was decreased in the brief separated group and more significantly decreased in dams subjected to 3h separation from their pups. Additionally, cerebral spinal fluid oxytocin was increased in dams of the brief separated group, which may be related to the increased handled-induced maternal care, as reported in the literature. A reduction in nitric oxide levels in the hippocampus in dams of the long separated group was also observed. It was also verify an increase in the risk-taking behavior by the 3h separated mothers. The 3h separated mother also demonstrated a diminished feeling of pleasure with a sucrose solution and a increased sensibility to a aversive solution, wich is congruent with a depressive like state profile. Furthermore, we shown a decrease in the dopamine D2 receptor quantity in the striatum of the 3 h separated mothers, wich could be related to a decrease in pleasure feeling (anhedonia) experienced in depression. It is concluded that the withdrawal of pups from their mothers for long periods make the mothers more susceptible to the development of depressive features.

Esse estudo foi realizado para verificar se a exposição a separações repetidas (por diferentes intervalos de tempo) de mães dos seus filhotes no período neonatal poderiam ser classificadas como indutoras de um estado do tipo deprimido em genitoras. Sessenta ratas Wistar prenhes foram divididas em 3 grupos: controle, separação por 10 minutos e separação por 3 horas. As intervenções neonatais foram realizadas nos dias 1-10 pós parto. Após o desmame as genitoras foram submetidas ao teste do nado forçado, ao teste do labirinto em cruz elevado e ao teste do odor de predador. Também foi avaliado o comportamento alimentar e os padrões de reatividade a um sabor doce e a um sabor amargo. Foi medido os níveis de ocitocina no líquido cefaloraquidiano, corticosterona plasmática e atividade hipocampal Na+, K+-ATPase, assim como a atividade das enzimas antioxidantes catalase, glutationa peroxidase, superoxido dismutase, produção de radicais livres, e a produção de óxido nítrico, além dos níveis dos receptores A2A de adenosina e D2 de dopamina no estriado dorsoventral e no hipocampo. Foi observado que somente a separação por 3 h induziu um aumento significativo no tempo de imobilidade no teste do nado forçado, o que é consistente com estudos prévios. A atividade hipocampal da Na+, K+-ATPase se mostrou diminuída no grupo separado por 10 minutos e mais significativamente diminuída nas genitoras submetidas a separação por 3 horas de seus filhotes. Adicionalmente, os níveis de ocitocina no líquido cefaloraquidiano se encontravam aumentados no grupo separado por 10 minutos, o que pode estar relacionado a um aumento no cuidado materno, induzido por esta manipulação dos filhotes, por parte das genitoras, como reportado na literatura. Uma redução nos níveis de óxido nítrico no hipocampo das genitoras separadas por 3 horas foi observado Nessas genitoras também foi verificado um aumento no comportamento de risco, uma diminuição no sentimento prazeroso frente a uma solução doce e aumento na sensibilidade a uma solução aversiva, o que é congruente a um perfil de estado do tipo deprimido. Além disso, nós verificamos uma diminuição na quantidade do receptor de dopamina D2 no estriado das mães submetidas a separação por 3 horas dos filhotes, o que poderia ser relacionado com uma diminuição no prazer (anedonia) que acontece na depressão. Conclui-se que a retirada dos filhotes das mães por longos períodos tornam essas mães mais susceptíveis ao desenvolvimento de características depressivas. / This study was carried out to ascertain whether exposure to repeated separations (different times) of mothers from their pups in the neonatal period could be classified as an induction of a depressive-like state in dams. Sixty Wistar rats were divided into 3 groups: control, brief separation and long-term separation. The neonatal interventions were done on postpartum days 1-10. After weaning, the dams were subjected to the forced swimming test, elevated plus maze and predator odor test. It was also evaluated the feeding behavior and the taste reactivity patterns to a sweet and to a bitter solution. It was mesaured cerebral spinal fluid oxytocin, plasma corticosterone, and hippocampal Na+, K+-ATPase activity, as well as the activity of the antioxidant enzymes catalase, glutathione peroxidase, superoxide dismutase, free radicals production, and the production of nitric oxide and the levels of adenosine A2A and dopamine D2 receptors in the dorsoventral striatum and hippocampus. It was observed that only the 3 h separation induced a significant increase in the immobility time of rats in the forced swimming test, which is consistent with previous studies. Hippocampal Na+, K+-ATPase activity was decreased in the brief separated group and more significantly decreased in dams subjected to 3h separation from their pups. Additionally, cerebral spinal fluid oxytocin was increased in dams of the brief separated group, which may be related to the increased handled-induced maternal care, as reported in the literature. A reduction in nitric oxide levels in the hippocampus in dams of the long separated group was also observed. It was also verify an increase in the risk-taking behavior by the 3h separated mothers. The 3h separated mother also demonstrated a diminished feeling of pleasure with a sucrose solution and a increased sensibility to a aversive solution, wich is congruent with a depressive like state profile. Furthermore, we shown a decrease in the dopamine D2 receptor quantity in the striatum of the 3 h separated mothers, wich could be related to a decrease in pleasure feeling (anhedonia) experienced in depression. It is concluded that the withdrawal of pups from their mothers for long periods make the mothers more susceptible to the development of depressive features.

Le stress prénatal est un sujet d'intérêt éthologique croissant en raison de ses effets sur la santé humaine et le bien-être des animaux. Cette thése de doctorat s’intéresse à la seiche Sepia officinalis, un modèle pratique dans lequel la progéniture en développement peut être séparée de leurs mères pour examiner diverses sources potentielles de stress en isolement expérimental. Plusieurs catégories de facteurs de stress ont été appliquées aux embryons et aux juvéniles et la progéniture résultante a été testée dans une série d'épreuves physiologiques et comportementales. L'objectif était de déterminer si différents types de stress prénatal affectent la seiche et, dans l'affirmative, comment ces effets se transmettent. Les données présentées démontrent que les stresseurs appliqués aux femelles reproductrices (stress maternel), ainsi que les stresseurs appliqués directement aux embryons (stress embryonnaire), affectent le comportement postnatal (y compris la structuration corporelle, la latéralisation cérébrale, la prédation et les schémas d'activité) la mémoire et / ou la neurobiologie (y compris les concentrations et le renouvellement de la monoamine, la taille des différents lobes cérébraux et la division cellulaire). Les résultats mettent en évidence la présence de trois voies par lesquelles le stress peut exercer des effets: sur le nombre de descendants produits par la femelle, la transmission de la femelle à sa progéniture et directement sur la progéniture elle-même. Les expériences ont également démontré qu'un facteur de stress complètement artificiel (lumière forte) affectait un éventail plus large de comportements chez la progéniture qu’un stress naturel (odeur de prédateur). Enfin, les données ont montré que l'environnement d'incubation et d’élevage peuvent également affecter la progéniture et méritent donc une attention particulière dans la formulation et l'interprétation des expériences avec cette espèce. Ces découvertes informent à la fois les pratiques de bien-être des seiches et d'autres céphalopodes (par exemple, réduisent la manipulation pour maximiser la reproduction) et élucident et renforcent les principes éthologiques qui s'appliquent au stress animal en général (par exemple la transmission des effets de stress de la mère à la progéniture). Compte tenu des informations fournies ici et dans de nombreuses autres études, la seiche et d'autres céphalopodes devraient continuer à servir de modèles comportementaux en éthologie et en biologie en général. / Prenatal stress is a subject of growing ethological interest due to its effects on human health and animal welfare. This Ph.D. thesis utilizes the cuttlefish Sepia officinalis, a convenient model in which developing offspring can be separated from their mothers to examine various potential sources of stress in experimental isolation. Several categories of stressors were applied to cuttlefish and cuttlefish eggs and the resulting offspring were tested in a range of physiological and behavioral tests. The goal was to determine if various types of prenatal stress affect cuttlefish, and if so, how these effects are transmitted. The data presented demonstrate that both stressors applied to reproducing females (maternal stress), as well as stressors applied directly to embryos (embryonic stress), affected post-natal behavior (including body patterning, brain lateralization, predation and activity patterns), learning, memory and/or neurobiology (including monoamine concentrations and turnover, the size of various brain lobes and cell division). The results highlight the presence of three pathways by which stress can exert effects: on the number of offspring produced by the female, transmission from the female to her offspring and directly on the offspring themselves. The experiments also demonstrated that a completely artificial stressor (bright light) affected a wider range of behaviors in offspring than a natural-occurring one (predator odor). Finally, the data showed that incubation and spawning environment can also affect offspring, and thus deserve attention in the formulation and interpretation of experiments with this species. These findings inform both welfare practices for cuttlefish and other cephalopods (e.g. reduce handling to maximize reproduction) as well as elucidating and reinforcing ethological principles that apply to animal stress in general (e.g. the transmission of stress effects from mother to offspring). Given the insight provided here and in numerous other studies, cuttlefish and other cephalopods should continue to serve as behavioral models in ethology and biology in general.