Os interneurônios do bulbo olfatório são elementos chave para o entendimento do processamento de odores. O papel funcional desses neurônios ainda não é bem compreendido, em especial o papel da célula periglomerular (PG). O presente trabalho consiste em construir um modelo biologicamente plausível da célula PG e investigar os efeitos dessa célula em conjunto com modelos da célula mitral e da célula granular. Esses modelos são acoplados através de conexões sinápticas inspiradas nas conexões existentes no bulbo olfatório, formando uma pequena rede simplificada. A rede é usada para analisar o efeito da inibição inicial da célula mitral por parte da célula PG e os mecanismos que podem influenciar o padrão de atividade da célula mitral. Através deste estudo, verifica-se que a célula PG pode influenciar na frequência, no tempo de disparo e gerar atrasos na propagação do potencial da célula mitral, agindo como um mecanismo de controle nas camadas iniciais do processamento de odores do bulbo olfatório. / Interneurons of the olfactory bulb are key elements for understanding odor processing. The functional role of these cells are not yet well understood, in particular the role of periglomerular cell (PG). This work aims at constructing a biologically plausible model of the PG cell to study effects of the coupling of this cell with model of mitral and granule cells of the olfactory bulb. Single cell models of these three cell types coupled by synaptic connections inspired on existing connections in the olfactory bulb, constituting a small and simple network. This network is used to investigate the effect of early lateral inhibition of the mitral cell by PG cell and the mechanisms witch can influence the output activity pattern of mitral cell. The study shows that the PG cell may influence the spike frequency and the spike timing of the mitral cell, as well as provoke delays in the propagation of action potential along this cell. Therefore, the PG cell may act as a control mechanism in the early odor processing stages in the olfactory bulb.

Over the last three decades there has been a significant increase in aquaculture production and the demand for farmed fish is predicted to rise further. More fish are being caught to become fishmeal in aquaculture, than for direct human consumption use, while a large number of fish stocks are being depleted. Many popular farmed species are carnivores and thus brought up on a diet consisting of fishmeal and fish oil. However, several studies have shown that several fish species can be brought up on a diet consisting of mussel meal instead of fishmeal. If so, this finding can possibly lead to a more sustainable fishing in the future by reducing the number of wild-caught fish. The purpose of this study has been to examine if mussel meal extract can induce foraging in the omnivorous species crucian carp (Carassius carassius), a commercial fish that is mainly farmed in China. Induced foraging can indicate that crucian carp could become accustomed to mussels, even though mussels are not part of its natural food source. The results revealed that foraging was induced in the crucian carp by conventional feed for carp, the control diet, but not by extract of mussels. / Vattenbruket har ökat markant under de senaste tre decennierna och idag går mer fisk till foderproduktion för fiskodlingar än vad som konsumeras direkt av människan. Detta är problematiskt då många fiskbestånd är utarmade, samtidigt ökar efterfrågan på fisk. Många populära matfiskar är rovfiskar som huvudsakligen matas med fiskbaserat foder. Ett flertal studier har emellertid visat att flera fiskarter potentiellt kan födas upp på blåmusslor (Mytilus edulis) istället för fiskbaserat foder. Foder som huvudsakligen baseras på musslor kan därför i framtiden möjligen bidra till att minska överexploatering av fisk. Denna studie undersökte om musselextrakt kan inducera ett födosök hos omnivoren ruda (Carassius carassius), som idag odlas och används som matfisk framförallt i Kina. I så fall kan det indikera att ruda möjligen kan vänjas vid musslor, trots att det inte ingår i fiskens naturliga föda. Resultaten i studien visade att ett födosök inducerades hos ruda gentemot extrakt av vanligt karpfoder, kontrollsubstansen, men inte gentemot musselextrakt.

AN ABSTRACT OF THE THESIS OF MARCUS C. ABSTON, for the Master of Science degree in ZOOLOGY, presented on 18 April 2017, at Southern Illinois University Carbondale. TITLE: EFFECTS OF OLFACTORY ENRICHMENT ON AFRICAN CHEETAHS (ACINONYX JUBATUS) MAJOR PROFESSOR: Dr. Carey Krajewski Environmental enrichment has been an essential part of felid husbandry in zoos, serving to reduce both physiological and psychological stress. Olfactory enrichment is one of many interventions used to prevent stereotypic behavior caused by stress in felids. However, little research has been done on this practice. The purpose of this study was to compare behavioral responses of four captive African cheetahs to six types of commercial fragrances used as olfactory enrichment stimuli. Three of these fragrances are marketed as “men’s cologne” and three as “women’s perfume”. The fragrances were also categorized as musky, spice, and floral types. Behavioral responses were recorded by live observations during 36 bouts at the St. Louis Zoo. There was a significant difference between cheetahs’ interaction time with male and female fragrances; they seemed to prefer male colognes. However, there was no significant difference in interaction time among fragrance types. Engagement behaviors varied among individuals (e.g. sniffing, scent rolling, pawing), but were similar to those reported by previous authors. These findings suggest that commercial fragrances may be a useful option for African cheetah olfactory enrichment.

As células-tronco do epitélio olfatório possuem a capacidade de diferenciação, regeneração de neurônios olfatórios e atuam no processo de mielinização das fibras nervosas. O objetivo desse trabalho foi verificar o potencial terapêutico de células-tronco do epitélio olfatório de ratos Wistar em terapia celular em coelhos submetidos à lesão medular. Foram utilizados ratos com idade de 2 meses e coelhos da raça nova Zelândia obtidos no Biotério do Departamento de Patologia da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Os fragmentos do epitélio olfatório dos ratos foram tratados e colocadas em cultivo em DMEM-F12 suplementado. Foram testadas nos coelhos nova Zelândia 4 tipos de lesão medular, hemisecção dorsal e ventral e secção lateral e total. Foi realizado teste de potencial teratogênico em camundongos NUDE e para terapia foram transplantadas 5x105 células em 4 coelhos submetidos a lesão medular ventral. A morfologia predominante das células em cultivo era fibroblastóide. Os ensaios de curva de crescimento e tendência a formação de colônia demonstraram que as condições de cultivo destas células estavam adequadas. Foi encontrada positividade para Vimentina, Oct-4, GFAP, OMP, Nanog, Citoqueratina-18 e Beta tubulina em imunofluorescência. Em citometria de fluxo foi encontrada negatividade para CD 113, CD 117 e Stro-1 e positividade para Vimentina, Nanog e OMP. Em análise por imunohistoquíca verificou-se marcação positiva para Vimentina, OMP, GFAP e Nanog. Verificou-se marcação positiva no material coletado por retrovírus GFP. Houve melhora clínica nos animais avaliados 21 dias após o transplante de células com retorno de alguns reflexos como o de propriocepção consciente e colocação tátil, o mesmo apresentou ainda reflexo de pedalagem. Conclui-se que o melhor modelo para indução da lesão medular em coelhos é a hemisecção ventral da medula e que as células-tronco olfatórias de ratos Wistar possuem grande potencial terapêutico em animais submetidos à lesão medular. / Stem cells from olfactory epithelium are capable of differentiation, regeneration of olfactory neurons and act in the myelination process of nerve fibers. The aim of this study was to verify the therapeutic potential of stem cells from the olfactory epithelium of Wistar rats in cell therapy in rabbits subjected to spinal cord injury. Rats were aged 2 months and New Zealand rabbits obtained in the bioterio of the Animal Pathology Department, Faculty of Veterinary Medicine, at University of Sao Paulo. Samples of the olfactory epithelium of rats were treated and placed in culture in DMEM-F12 supplemented. Four types of spinal cord injury were tested in New Zealand rabbits: hemisecction dorsal and ventral, total and lateral section. The teratogenic potential test was made in NUDE mices. For therapy were transplanted 5x105 cells in 4 rabbits subjected to spinal cord injury in the ventral region. The cells showed predominant fibroblastoid morphology. Tests for growth curve and colony formation demonstrated that culture conditions in these cells were suitable for the development of these cells. In the immunofluorescence analyses the cells showed positive reaction for vimentin, Oct-4, GFAP, OMP, Nanog, cytokeratin-18 and beta tubulin. In flow cytometry analyses was found negative reaction for CD 113, CD 117 and Stro-1 and positive reaction for vimentin, Nanog and OMP. In immunohistochemistry analysis were observed positive reaction for vimentin, OMP, GFAP and Nanog. Positive labeling was showed on the collected material for GFP. Clinical improvement occurred in the animals evaluated 21 days after cell transplantation. With some reflections about how the placement of conscious proprioception and tactile, it also presented a reflection of pedaling. After this, we concluded that the better model for induction of spinal cord injury in rabbits is the hemisecction ventral and the olfactory stem cells of Wistar rats showed a great therapeutic potential in animals subjected to spinal cord injury.

La représentation corticale des informations sensorielles est fondamentale dans la perception, la reconnaissance et la mémorisation des différents objets de l’environnement. Les mécanismes de codage d’un stimulus sensoriel au niveau d’une population neuronale prennent place dans le temps et l’espace, deux composantes que nous avons étudiées successivement dans ce travail de thèse. Dans le bulbe olfactif, la dynamique des activités neuronales se traduit par de larges oscillations du potentiel de champ local. Plusieurs études indiquent que ces activités oscillatoires varient en fonction de l’environnement olfactif ou de l’expérience de l’animal. Toutefois peu d’études ont comparé les réponses oscillatoires aux odeurs entre les états d’éveil et d’anesthésie. La composante spatiale du traitement olfactif dans le bulbe se manifeste par l’activation d’unités fonctionnelles, les glomérules. Visualisées par des techniques d’imagerie fonctionnelle, ces activités distribuées à la surface du bulbe olfactif forment une topographie lâche des molécules olfactive reconnues en périphérie par les neurorécepteurs olfactifs. L’existence d’une plasticité de ces cartes spatiales, un aspect crucial du codage de la représentation de l’information dans d’autres modalités sensorielles, est débattue dans le bulbe olfactif. Dans ce cadre, les travaux présentés dans cette thèse s’articulent autour de deux questions : quel est l’impact de l’état d’éveil de l’animal sur les oscillations du potentiel de champ local enregistré dans le bulbe olfactif ? Existe-t-il une plasticité des cartes glomérulaires suite à un apprentissage associatif ? Par l’enregistrement, chez les mêmes souris, des régimes oscillatoires en condition éveillée et anesthésiée (par un mélange de kétamine-xylazine ou kétamine-médétomidine), nous montrons que les profils de réponses oscillatoires évoquées par l’odeur sont similaires dans les deux conditions, et que l’activité spontanée est modulée différemment selon le régime anesthésique. Pour étudier le codage spatial nous avons en premier lieu visualisé et décrit les variations des cartes glomérulaires évoquées par les odeurs en enregistrant par imagerie optique deux types de signaux basés sur l’activité métabolique, le signal intrinsèque et l’autofluorescence des flavoprotéines. Suite au développement d’une fenêtre optique dans le bulbe olfactif en chronique, nous avons pu comparer les cartes spatiales obtenues avant et après un apprentissage olfactif. Nous avons mis en évidence un impact différentiel de deux types de conditionnement sur la représentation spatiale de l’odeur. / The cortical representation of sensory information is fundamental for perception, recognition and storage of different objects in the environment. Sensory coding by neuronal population has two components, time and space, that we studied successively in this thesis. In the olfactory bulb, the rhythmic and transient’s dynamic of the extracellular activities are represented as large oscillations of the local field potential. Several studies indicate that these oscillatory activities vary with the olfactory environment or the experience of the animal. However, very few studies have compared oscillatory profiles evoked by odors between awake and anesthetized animals. The spatial component of sensory processing in the olfactory bulb is characterized by the activation of functional units, the glomeruli, which can be visualized by functional imaging techniques. These distributed activities at the surface of the olfactory bulb form a coarse topography of the olfactory molecules that bind on peripheral olfactory neuroreceptors. However, the fact that these spatial maps are plastic, a crucial aspect of encoding the representation of information in other sensory modalities, is still debated in the olfactory bulb. In this context, the work presented in this thesis is driven by two questions: what is the impact of the level of arousal on the oscillations of local field potential recorded in the olfactory bulb? Are glomerular maps plastic after associative learning? In the same mice, we recorded oscillatory activities in awake and anesthetized conditions (using ketamine-xylazine or ketamine-medetomidine mixtures). We show that the profiles of oscillatory responses evoked by odor stimulations are similar in the two conditions, and that spontaneous activity is differentially modulated according to the anesthetic regime. To study odor spatial coding, we used optical imaging to record odor-evoked glomerular maps using two types of metabolic signals, the intrinsic signal and flavoproteins autofluorescence. We developed chronic optical window on the olfactory bulb that allowed us to compare the spatial maps obtained before and after olfactory learning. We have shown that two types of conditioning exerted a differential impact on the spatial representation of the odor.

Predation by olfactory meso-predators has a large impact on avian nest success, particularly for ground-nesting waterfowl. Olfactory predators rely on odors to locate their prey. Weather conditions (e.g. wind speed, humidity, and temperature), vegetation, and landscape features affect the dissipation rate of odors and could affect the foraging efficiency of olfactory predators. I conducted 2 studies to determine if weather and landscape impact predator foraging ability and behavior: a predator survey study and an artificial nest study. The objective of the predator survey was to investigate how landscape and weather conditions interact to influence the distribution of olfactory meso-predators [e.g. red foxes (Vulpes vulpes), skunks (Mephitis mephitis), and raccoons (Procyon lotor)] in their nightly foraging on the dike. Specifically, I examined how wind speed, wind orientation, temperature, and humidity affect the distribution, number, and species of olfactory meso-predators foraging on the Arthur V. Watkins Dike at Willard Bay State Park and Reservoir. The objective of the artificial nest study was to determine if weather, vegetation, or nest location relative to a large-scale surface feature have an effect on survival of artificial ground-nests in an area dominated by olfactory meso-predators. Artificial nests were placed on the dike throughout the summer of 2009. Spotlighting surveys for predators were conducted from August 2008 to August 2009. I found that section of the dike, time since study initiation, terrain type on the dike, wind speed, and vegetation height during daylight hours affected nest survival. The results indicated that predators formed olfactory search images in that nest survival decreased over the summer, while predator populations remained constant. I observed foxes, skunks, and raccoons while spotlighting for predators. After accounting for time, wind speed and direction were significant predictors of predators' nightly foraging activity with most predators observed when wind speeds were 2 to 4 m/s and winds were blowing from the northwest. Overall the model accounted for 75% of the nightly variation in predator numbers. Additionally, wind speed and direction impacted where predators were foraging. There were interspecific differences among predators in their responses to wind speed with raccoons being observed more than skunks and foxes when the wind was calm and blowing from the south. The results of the spotlighting data indicate that wind speed and direction have a strong effect on foraging activity. Overall, I concluded that wind speed affects predator foraging ability and behavior.

Selecting a nest site is an important decision for waterfowl. Because most nest failure is due to depredation, the primary selective pressure in choosing a nest site should be to reduce depredation risk. This task is difficult because predators use differing tactics to locate nests, such as olfactory or visual cues. I investigated several components of waterfowl nest-site selection and success on sites with shelterbelts (planted tree-rows) in North Dakota, during the 2006 and 2007 nesting seasons. I found that meteorological conditions impacted nest depredation; artificial nests were more likely to be depredated when either temperature or dew point was high. These meteorological conditions should improve foraging efficiency for olfactory predators by increasing odor concentration. Waterfowl selected nesting sites with greater visual concealment than random locations (lateral concealment). However, the only difference found between successful and depredated nests was lateral dispersion, an olfactory concealment characteristic. Nest density was higher in areas without shelterbelts than in areas near shelterbelts. Nest success for waterfowl decreased as shelterbelt height increased. Other shelterbelt characteristics, like porosity and orientation, did not affect nest success or nest density. Given that nest predators differ in foraging habitat, temporal patterns of activity, and searching modalities, nest site characteristics that conceal the nest from 1 predator species may increase its vulnerability to another predator. For instance, risk due to olfactory predators should be reduced near shelterbelts because locating nests would be more difficult as turbulence is generated by the shelterbelts. Concomitantly, shelterbelts could also increase the presence of visual predators, by providing nesting sites and vantage points. In my study, any benefits shelterbelts provide in reducing nest depredation by olfactory predators may have been offset by increasing nest depredation from visual predators. Hence nesting near shelterbelts was neither a liability nor a benefit to ducks.

The adaptability and robustness of the central nervous system is partially explained by the vast diversity of neuronal identities. Molecular mechanisms generating such heterogeneity have evolved through multiple independent pathways. The olfactory sensory system provides a unique and tractable platform for investigating at least two orthogonal gene expression systems that generate neuronal diversity through stochastic promoter choice: olfactory receptor genes and clustered protocadherins. Olfactory sensory neuron identity is defined by the specific olfactory receptor (OR) gene chosen. Greater than 1300 OR genes are scattered throughout the mouse genome, and expression of an OR defines a unique sensory neuron class that responds to a selective set of odorants. This work further delineated an unprecedented network interchromosomal (trans) interactions indispensable for singular OR choice. In a largely orthogonal gene expression system, I sought to understand the molecular mechanisms governing stochastic protocadherin choice. Clustered protocadherins are an evolutionary- conserved system that is involved in cell-cell identification through a series of homo- and heterophilic interactions. This work uncovered a methylation-dependent mechanism for generating stochastic gene expression in the context of cis-regulatory elements. Overall, this work highlighted divergent cis and trans transcriptional regulatory mechanisms for generating stochastic gene expression and neuronal diversity.

Evidence from various sources suggests that schizophrenia may result from altered brain development. The adult olfactory epithelium provides an available 'window' on neuronal development because new neurons are formed there throughout life. This thesis set out to test the neurodevelopmental hypothesis of psychotic disease. Two cell-based models, skin fibroblast and olfactory mucosa culture, were employed to investigate this hypothesis. In order to first demonstrate the utility of olfactory mucosa culture as a model of neurodevelopment, and to allow the candidate to gain proficiency in the culture of this tissue, an investigation of the mitogenic and differentiating properties of insulin-like growth factor-I within this system was undertaken. Insulin-like growth factor-I has multiple effects within the developing nervous system but its role in neurogenesis in the adult nervous system is less clear. The adult olfactory mucosa is a site of continuing neurogenesis that expresses insulin-like growth factor-I, its receptor, and its binding proteins. The action of insulin-like growth factor-I was assayed in several serum-free culture systems combined with bromodeoxyuridine labelling of proliferating cells and immunochemistry for specific cell types. Once proficiency in olfactory mucosa culture was gained, this model was applied to biopsied olfactory mucosa from schizophrenia and bipolar disorder patients in order to test the developmental parameters of adhesion, cell proliferation, and cell death in a neural tissue. It was previously shown that olfactory cultures from individuals with schizophrenia had increased cell proliferation and attached less frequently than cultures from healthy controls suggesting disrupted neurogenesis. An aim of this study was to replicate those observations in individuals with schizophrenia and and extend them to individuals with bipolar disorder. After completion of the cell and tissue culture assays, microarray analysis of these cell-based models was used to reveal gene expression differences present between patients and healthy controls. Microarray analysis is a complicated technique and the limited amounts of RNA that can be extracted from a single nasal biopsy further compounds this issue. In order to obtain enough material for microarray hybridization RNA samples underwent antisense amplification. Therefore, with the aim of allowing the candidate to gain proficiency in both these techniques prior to microarray analysis of olfactory biopsies from patients with schizophrenia and bipolar disorder, a pilot microarray study of cultured skin fibroblasts from schizophrenia patients and healthy controls was performed. The present findings show that insulin-like growth factor-I and its receptor were expressed by globose basal cells (the neuronal precursor), by neurons and by olfactory ensheathing cells, the special glia of the olfactory nerve. Insulin-like growth factor-I reduced the numbers of proliferating neuronal precursors, induced their differentiation into neurons, and promoted morphological differentiation of neurons. In contrast, this growth factor was mitogenic for olfactory ensheathing cells. The evidence suggests that insulin-like growth factor-I is an autocrine/paracrine signal that induces neuronal precursors to differentiate into olfactory sensory neurons and induces olfactory ensheathing cells to proliferate and that olfactory mucosa culture is valuable in modelling neurodevelopmental processes. When the olfactory musoca culture model was applied to patients with psychosis, a two-fold increase in proliferation of neural cells was found in schizophrenia compared to controls and bipolars. In bipolar cultures there was a 3-fold increase in cell death compared to controls and schizophrenia. Microarray analysis of cultured skin fibroblasts revealed differential expression of over 1000 genes between patients and controls. Inspection of the significant data showed alterations to gene expression between groups in the cell cycle, oxidative phosphorylation, TCA cycle and oxidative stress pathways. Gene expression in each of these pathways was predominately decreased in schizophrenia. Quantitative PCR analysis of selected differentially expressed genes involved with cell cycle regulation validated the increased expression of vitamin D receptor, and decreased expression of proliferating cell nuclear antigen and DEAD (Asp-GIu-Ala-Asp) box polypeptide 5 in skin fibroblasts from patients with schizophrenia. Microarray analysis of biopsied olfactory mucosa showed 146 and 139 differentially expressed genes in schizophrenia and bipolar disorder respectively, compared to controls. Consistent with increased mitosis in schizophrenia biopsy cultures three genes that function to positively influence cell cycle had increased expression. In the bipolar disorder group a dysregulation of the phosphatidylinositolsignalling pathway was seen; five genes that either directly function within or interact with this pathway had decreased expression. There is speculation that the therapeutic effect of psychotropic drugs acting upon this pathway in bipolar disorder involves reduction of neuronal cell death. Increased mitosis of neural cells has now been observed in two separate groups of schizophrenic patients indicating a robust finding. The use of fibroblast and olfactory mucosal tissue can be used to study biological and genetic aspects of neurodevelopment in living humans both with and without psychotic disease. Biopsied olfactory mucosa provides benefits over the use of autopsied material for study of psychotic disease because post-mortem duration and agonal factors that lead to tissue, protein and nucleic acid degradation are not an issue. This study provides evidence for a neurodevelopmental aetiology of schizophrenia and bipolar disorder acting at the level of cell cycle control. Subtle changes in the timing of cell cycle regulation could account for the brain pathologies observed in these diseases. Olfactory mucosa culture is a valuable model of neurodevelopmental processes.

<p>For many years, primates have been considered to be animals with a poorly developed sense of smell. However, in recent years several studies have shown that at least some primate species have a high olfactory sensitivity for a variety of odorants. The present study used a two-choice instrumental conditioning paradigm to test the olfactory sensitivity for six aromatic aldehydes in four spider monkeys (Ateles geoffroyi). With helional, cyclamal,canthoxal and lilial all animals discriminated concentrations below 1 ppm from the odorless solvent, with single individuals even scoring better. With 3-phenyl-propionic aldehyde all animals detected concentrations below 2 ppb, and with bourgeonal even below 0.3 ppb. The detection thresholds of the odorants changed systematically with molecular structure. Addition of a dioxo or methoxy group to the benzene ring led to an increase in threshold values,while the absence of a methyl group close to the aldehyde moiety was linked to a low threshold value for the odorant. The study shows that spider monkeys have a well developed olfactory sensitivity for aromatic aldehydes.</p>