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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aversive conditioning on horse back: A management alternative for grassland systems threatened by sedentary elk populations

Spaedtke, Holger Ronald 11 1900 (has links)
Loss of migratory behaviour in ungulates has been observed worldwide and invites new tools for managing the habitat degradation that results from these sedentary populations. We assessed use of aversive conditioning on horseback as a means of reducing grazing pressure and restoring migratory behaviour in elk (Cervus elaphus) at the Ya Ha Tinda Ranch, which is an important wintering range. We conditioned elk by herding them daily in the direction of their historic migratory route and monitored changes in elk distribution and grassland biomass each year. After three summers of aversive conditioning treatments, summer elk presence on the targeted grassland had declined substantially and grassland biomass had increased. Although elk use shifted in the desired direction, we did not detect any longer-distance migration in targeted elk. Our research suggests that aversive conditioning on horseback can temporarily reduce grazing pressure on threatened grasslands, but is unlikely to change migratory behaviour. / Ecology
2

Aversive conditioning on horse back: A management alternative for grassland systems threatened by sedentary elk populations

Spaedtke, Holger Ronald Unknown Date
No description available.
3

Elimination of Cigarette Smoking, Employing a New Aversive Conditioning Procedure

Himes, Jerome A. 05 1900 (has links)
The study was designed to find a response on the behavioral level that would be an effective index across subjects for determining when conditioned aversive suppression of a response had been achieved. Ten male volunteers received shock during trials in which they had to smoke. Half of the subjects received a brief but more intense shock when they stopped smoking during a trial. A comparison of these subjects to the others showed their average amount of smoking suppression in pre- and post-treatment rates to be significantly (P < .025) greater. In addition, these subjects showed conditioned emotional responding. It was concluded that this behavioral level response was an effective index for determining when suppression of smoking would occur.
4

Applications of learning theory to human-bear conflict: the efficacy of aversive conditioning and conditioned taste aversion

Homstol, Lori Unknown Date
No description available.
5

Applications of learning theory to human-bear conflict: the efficacy of aversive conditioning and conditioned taste aversion

Homstol, Lori 06 1900 (has links)
I tested the efficacy of aversive conditioning (AC) and conditioned taste aversion (CTA) on American black bears (Ursus americanus) in Whistler, British Columbia. Black bears subjected to 3-5 day AC programs responded by increasing their wariness toward humans, while control bears habituated. Bears were located closer to human developments during daylight hours after AC treatments. However, there was no difference in the proportion of utilization distribution that overlapped with developed areas in control or AC-treated bears. CTA may be effective for managing specific attractants that are difficult to secure from bears. Bears appeared to distinguish between baits treated with thiabendazole and baits that were not treated, but by using a protocol that caused severe illness and left the source of illness in doubt, I induced taste aversions to apples in 4 bears. Using both AC and CTA may help wildlife managers mitigate human-wildlife conflicts non-lethally more effectively. / Ecology
6

Neural circuits of the mouse olfactory cortex : linking neural connectivity to behavior / Circuits neuronaux du cortex olfactif murin : relation entre connectivité neuronale et comportement

Vieira, Inês 30 October 2017 (has links)
Comment les odeurs contrôlent-elles le comportement animal ? Dans ma thèse, j'ai utilisé des manipulations optogénétiques et chimiogénétiques in vivo de l'activité neurale combinées à des analyses comportementales pour explorer l'organisation de circuits cérébraux impliqués dans des comportements olfactifs chez la souris. J'ai mis au point un test de conditionnement aversif olfactif indépendant de l'intensité des odeurs. J'ai démontré que les souris pouvaient généraliser une réponse aversive en présentant différentes concentrations d'odeurs. J’ai ensuite testé si les souris pouvaient apprendre cette tâche en inactivant les interneurones exprimant la parvalbumine dans le cortex olfactif (piriforme). J'ai trouvé que l’inactivation des cellules PV, n'était pas suffisante pour abolir l'aversion aux odeurs acquise, ce qui suggère que des composants de circuits neuronaux supplémentaires contribuent à la perception de l'odeur indépendamment de sa concentration. Ensuite, j'ai tenté de comprendre la constitution relative des différentes voies neurales du piriforme dans ce comportement d’aversion apprise. À l'aide d'outils génétiques et viraux, j'ai ciblé des sous-populations distinctes de neurones piriformes, et j'ai constaté que l'activité neurale induite par la lumière dans les cellules du piriforme projetant vers le bulbe olfactif et vers le cortex préfrontal, mais pas dans les cellules du piriforme projetant vers l’amygdale corticale et vers le cortex entorhinal latéral était suffisante pour supporter le conditionnement aversif. Ces résultats contribuent à mieux comprendre les propriétés fonctionnelles des circuits neuronaux corticaux pour l'olfaction. / How do odors control animal behavior ? In my thesis, I have used in vivo optogenetic and chemogenetic manipulations of neural activity combined with behavioral analyses to explore the organization of brain circuits involved in olfactory behaviors in mice. In the first part of the thesis, I established an odor intensity-independent olfactory conditioning task. I demonstrated that mice were able to generalize a learned escape behavior across a range of different odor concentrations. I then tested if by silencing Parvalbumin-expressing interneurons in the olfactory (piriform) cortex, a candidate cell population for mediating odor concentration invariance, mice would fail to learn the task. I found that silencing PV cells was not sufficient to abolish learned aversion, suggesting that additional neural circuit components contribute to concentration-invariant odor perception. Next, I asked whether different piriform neural output pathways differed in their ability to support learned aversion. Using viral-genetic tools, I targeted distinct subpopulations of piriform neurons and I found that light-induced neural activity in only piriform principle cells could drive a behavioral response. Furthermore, I tested the sufficiency of subpopulations of piriform projection neurons to drive learned aversion. I found that photostimulation of olfactory bulb- and prefrontal cortex-projecting piriform neurons was sufficient to support aversive conditioning, but not the photostimulation of cortical amygdala- and lateral entorhinal cortex-projecting piriform neurons. Together, these results provide new insights into the functional properties of cortical neural circuits for olfaction.
7

Apprentissage et mémoire chez les insectes vecteurs de maladies humaines / Learning and memory in disease vector insects

Vinauger, Clément 21 October 2011 (has links)
En permettant aux animaux de faire face à des environnements variables, l'apprentissage et la mémoire contribuent à l'optimisation de leur fitness, en leur permettant d'extraire et d'utiliser des informations, de façon à réduire l'incertitude associée à des environnements imprévisibles. Parmi les insectes, la drosophile et l'abeille domestique sont considérés comme des modèles classiques pour l'étude de l'apprentissage et de la mémoire. Les travaux réalisés sur ces derniers ont apporté une quantité considérable d'informations concernant les bases génétiques, neurobiologiques et moléculaires de ces processus, et ont permis de rendre compte du niveau de complexité des capacités cognitives des insectes. Cette somme de connaissances fondamentales acquises chez ces insectes contraste étonnamment avec le faible niveau de connaissance concernant la cognition des espèces impliquées dans des problématiques qui touchent la santé humaine et animale. Pourtant, il est largement admis que l'étude détaillée des capacités cognitives des insectes vecteurs de maladies constitue un aspect prioritaire pour la compréhension de leurs adaptations à la vie hématophage, de leur importance vectorielle, ainsi que pour le développement de nouveaux outils pour leur contrôle. Les travaux réalisés à ce jour chez les vecteurs, principalement chez les moustiques, ont été menés dans des contextes naturels ou peu contrôlés et ne proposent donc pas de démonstration formelle d'apprentissage. Le principal objectif de ce travail de thèse est de proposer un cadre expérimental contrôlé permettant de mettre en évidence et caractériser les capacités d'apprentissage chez la punaise hématophage \textit{Rhodnius prolixus}. \`A la différence des moustiques, les caractéristiques biologiques de cette punaise hématophage, responsable de la transmission de la Maladie de Chagas en Amérique Latine, permettent l'adaptation de protocoles expérimentaux largement validés chez les drosophiles et l'abeille domestique. Nos résultats montrent dans un premier temps que ces insectes sont capables d'apprendre et d'associer la présentation d'une même odeur dite neutre (l'acide lactique), c'est-à-dire qui ne provoque ni attraction ni répulsion lorsqu'elle est présentée seule, avec soit la possibilité d'obtenir une récompense (un repas sanguin, conditionnement appétitif), soit avec la possibilité de recevoir une punition (un choc mécanique, conditionnement aversif). Nous avons également montré que l'apprentissage et la mémoire sont également impliqués dans le choix des hôtes. Les insectes ont en effet associé la présentation d'un choc mécanique avec le complexe d'odeur d'hôtes naturels, biaisant leur préférence lors d'un test de choix réalisé après l'entraînement. Dans un second temps, nous avons adapté à notre modèle d'étude le paradigme de conditionnement de la réponse d'extension du proboscis, développé chez les modèles classiques, ce qui a permis la caractérisation des capacités d'apprentissage, de la durée de rétention à la régulation par des horloges circadiennes. Ces travaux proposent également un paradigme expérimental, reproductible et efficace permettant d'analyser les mécanismes fins qui sous-tendent les processus d'apprentissage et de mémorisation. Dans son ensemble, cette étude apporte la première preuve expérimentale de la capacité d'apprentissage d'insectes vecteurs de la maladie de Chagas et propose des outils expérimentaux et méthodologiques permettant d'améliorer la compréhension des processus associés chez les insectes hématophages en général. Les résultats sont également discutés dans le contexte de la sélection d'hôte et de la transmission des parasites. / Learning and memory contribute to animals' fitness by allowing them adapting to variable environments. Thses two processes make them able to extract and use information from their environment in order to reduce the uncertainty associated with unpredictible environments. Among insects, fruit flies and honeybees are considered as classical models for the study of learning and memory. The amount of work that has been done on these models provide a considerable amount of information regarding the genetic, neurobiological and molecular basis of these processes and revealed the complexity of insects' cognitive abilities. All this knowledge acquired in model species, contrasts surprisingly with the lack of knowledge available regarding insect species that are involved in animal and human diseases transmission. Yet, it has been aknowledge that the detailed study of vectors cognitive abilities would allow the understanding of their adaptation to haematophagy, of their vectorial importance and provide new tools for diseases control. Up to date, studies focusing on disaese vectors, mainly in mosquitoes, were conducted in natural or not completely controled contexts and thus no clear demonstration of learning and memory is availaible.The main goal of this work was to provide a controled experimental context allowing the strudy of learning abilities in the haematophagous bug \textit{Rhodnius prolixus}. Our results show that these insectes are able to learn to associate the delivery of a same neutral odour either with the possibility to obtain a reward (blood-meal, appetitive conditioning) or with the possibility to receive a punishment (mechanical shock, aversive conditioning). We also showed that learning ans memory are involved in host selection processes. In a second part, we adapted to our biological model the paradigm of proboscis extension response conditioning, which allowed us to analyse and characterize its learning abilities. The maximal retention duration as well as the modulation of learning abilities by circadian clocks were evinced. Taken as a whole, this work provides the first experimental demonstration of learning abilities in Chagas disease vectors and provides experimental and methodological tools; These latters should allow improving the understanding of the mechanisms that are underlying cearning abilities of haematophagous insects in general. Results are also discussed in the context of host selection and parasite transmission.
8

Variação circadiana da expressão da sintase neuronal de óxido nítrico (nNOS) no hipocampo e o condicionamento contextual aversivo em pombos (Columba livia) / Circadian variation in expression of neuronal nitric oxide synthase (nNOS) in the hippocampus and contextual aversive conditioning in pigeons (Columba livia),

Machado, Aline Vilar da Silva 18 August 2018 (has links)
Orientador: Elenice Aparecida de Moraes Ferrari / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T00:49:19Z (GMT). No. of bitstreams: 1 Machado_AlineVilardaSilva_M.pdf: 2487506 bytes, checksum: ec15fc1b78bef814d6d459499276cdf5 (MD5) Previous issue date: 2011 / Resumo: A ritmicidade circadiana, expressa na alteração do comportamento e em aspectos morfofisiológicos e moleculares ao longo das 24 horas do dia, é uma das funções básicas dos organismos vivos. Os processos comportamentais e os mecanismos moleculares no hipocampo, que estão envolvidos na aprendizagem e memória, demonstram oscilação circadiana. Vários estudos sugeriram que o condicionamento clássico aversivo é afetado pelo sistema de temporização circadiana e que a oscilação circadiana de vias moleculares específicas é requerida para a consolidação da memória aversiva. O presente trabalho investigou a oscilação circadiana da expressão da nNOS e da atividade da proteína NOS no hipocampo de pombos e as suas relações com a modulação temporal do condicionamento contextual aversivo. Na Parte I, caracterizou-se o padrão temporal da expressão da nNOS, que foi detectada por Western Blotting e o padrão temporal da atividade enzimática da NOS, determinada pela quantidade de L-citrulina produzida por minuto e por micrograma de proteína na reação. Na Parte II, nos horários de mínima e máxima atividade enzimática da proteína, pombos foram treinados e testados em condicionamento aversivo ao contexto. As sessões foram gravadas para posterior análise comportamental. Após o teste foi realizada a imunoistoquímica para marcação da nNOS em neurônios do hipocampo. Foi evidenciada ritmicidade circadiana significativa (p < 0,05) na expressão protéica da nNOS e na atividade enzimática da NOS, segundo os valores fornecidos pelo método Cosinor para caracterização do padrão temporal. As médias da densitometria óptica dos grupos com horários mais próximos da acrofase - ZT04 (10hs; 0,944 ± 0,12) e a batifase - ZT16-(22hs; 0,572 ± 0,16) foram significativamente diferentes (F5,18 p < 0,0001). Os grupos condicionados, em ambos os horários, mostraram maior duração e maior ocorrência do comportamento de congelamento do que os controles (p < 0,05). Houve uma variação dia-noite para o comportamento de congelamento nos grupos controles (p < 0,05). A marcação de células nNOS-positivas foi maior no hipocampo dos grupos condicionados sendo que o total de células nNOS-positivas na área dorsal do grupo experimental testado à noite foi maior do que aquele observado nos grupos controles e no experimental da manhã (p < 0,05). Os dados mostraram que a expressão protéica da nNOS e da atividade enzimática da NOS no hipocampo de pombos mostram uma oscilação que caracteriza um padrão temporal circadiano. Tanto no horário de máxima como no de mínima atividade da nNOS, o condicionamento contextual aversivo resultou em medo condicionado ao contexto e em expressão de células nNOS-positivas no hipocampo que foi maior nos pombos condicionados do que nos controles. Contudo, no hipocampo do grupo testado à noite houve um maior número de células nNOS-positivas. Esse dado estimula questionamento sobre se ocorreria a ativação de mecanismos compensatórios para o aumento da expressão da proteína nNOS, quanto essa é requisitada em situações de baixa disponibilidade / Abstract: The circadian rhythm, expressed in changing behavior and the morphophysiologic and molecular aspects over 24 hours of the day is one of the basic functions of living organisms. The behavioral processes and molecular mechanisms in the hippocampus, which are involved in learning and memory, show circadian oscillation. Several studies have suggested that classical fear conditioning is affected by the circadian timing system and the circadian oscillation of specific molecular pathways is required for the consolidation of aversive memory. This study investigated the circadian oscillation of nNOS expression and activity of NOS protein in the hippocampus of pigeons and their relationship with the temporal modulation of aversive contextual conditioning. In Part I, we have characterized the temporal pattern of nNOS expression, which was detected by Western blotting and temporal pattern of NOS enzyme activity, determined by the amount of L-citrulline produced per minute and per microgram of protein in the reaction. In Part II, at the times of minimum and maximum activity of the protein, pigeons were trained and tested in aversive conditioning to context. The sessions were taped for later behavioral analysis. After the test was performed immunohistochemical for labeling of nNOS in neurons in the hippocampus. Circadian rhythm was evident (p <0.05) in nNOS protein expression and enzyme activity of NOS, according to figures provided by Cosinor method to characterize the temporal pattern. The mean optical density of groups with times closer to the acrophase - ZT04 (10hrs; 0.944 ± 0.12) and nadir - ZT16-(22hs; 0.572 ± 0.16) were significantly different (F5, 18 p <0.0001 ). The groups conditioned in both schedules, showed more frequent and longer duration of freezing behavior than controls (p <0.05). There was a day-night variation for freezing behavior in control groups (p <0.05). Labeling of nNOS-positive cells was higher in the hippocampus of the groups conditioned with total nNOS-positive cells in the dorsal area of the experimental group tested at night was higher than that observed in control groups and experimental group in the morning (p <0.05). The data showed that nNOS protein expression and enzymatic activity of NOS in the hippocampus of pigeons show an oscillation that characterizes a circadian temporal pattern. Both at the time of maximum as the low activity of nNOS, the aversive contextual conditioning resulted in fear conditioning to context and expression of nNOS-positive cells in the hippocampus was higher in pigeons conditioned than in controls. However, in the hippocampus of the group tested in the evening there was a greater number of nNOS-positive cells. This fact encourages questioning of whether there would be activation of compensatory mechanisms for the increased expression of nNOS protein, as this is required in situations of low availability / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular
9

Organização temporal em processos de condicionamento classico aversivo e na expressão da proteina Zenk no hipocampo de pombos (C. livia) / Temporal organization of classical aversive conditioning processes and expression of Zenk protein in the hippocampus of pigeons (C. livia)

Canova, Fernando, 1980- 14 August 2018 (has links)
Orientador: Elenice Aparecida de Moraes Ferrari / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-14T04:52:12Z (GMT). No. of bitstreams: 1 Canova_Fernando.pdf: 32640695 bytes, checksum: 6c06f9d94ba0675ea059bb7d42685788 (MD5) Previous issue date: 2009 / Resumo: Uma grande parte do conhecimento sobre as bases e mecanismos neurais dos processos de aprendizagem, memória e amnésia fundamenta-se na investigação dos correlatos neurais do comportamento de animais não humanos em situações aversivas. Vários estudos têm resultados sugestivos de que o condicionamento clássico aversivo é afetado pelo sistema de temporização circadiana. As análises do condicionamento clássico aversivo e da resposta condicionada de congelamento (FRZ) são úteis para as análises do comportamento e dos processos mecanismos neurais subjacentes. Estudos prévios mostraram a indução da expressão de Zenk no hipocampo de pombos pelo treino em condicionamento clássico aversivo e pelo teste no contexto aversivo. O presente estudo investigou as variações dia - noite na aquisição e na evocação do condicionamento clássico aversivo e na expressão da proteína Zenk no hipocampo. O Experimento I avaliou o condicionamento ao contexto em pombos divididos em grupos condicionados (EC), controle (CC) e manipulação (CM) e o Experimento II investigou o condicionamento aversivo ao som previamente associado ao choque utilizando de animais que receberam som-choque pareados (EP), som-choque não pareados (NP) ou som(GS). Nos dois experimentos foi utilizado o fotoperíodo com pulsos de luz (15 min) às 6h (ZT00) e às 18h (ZT12), sendo as sessões realizadas nos horários ZT02 e ZT14. Os resultados do Experimento I indicaram diferença significativa na ocorrência de congelamento entre os grupos (p<0,05), mas não entre os horários (p>0,05). Comparações entre bloco final do treino e bloco inicial do teste mostraram queda significativa na ocorrência de congelamento no bloco inicial do teste no grupo EC ZT02 (p<0,05, mas não no EC ZT14 (p>0,05). A análise de células Zenk positivas no hipocampo mostrou aumento significativo na região HpV em relação a HpD do grupo EC ZT02 em comparação aos demais grupos (p<0,05), demonstrando uma diferença significativa de horário. Houve aumento significativo na marcação de núcleos Zenk-positivos em HpVM do grupo EC ZT02 em comparação aos demais grupos (p<0,05) e em relação a HpVL (p<0,05). No Experimento II houve maior ocorrência de exploração cautelosa nos grupos EP e NP (p>0,05) em comparação aos grupos GS (p<0,05) e diferença significativa na ocorrência de congelamento entre os grupos EP e GS (p<0,05), mas não entre os horários (p>0,05). A marcação de núcleos Zenk-positivos em HpV foi maior do que em HpD nos animais que receberam som e choque pareados ou não-pareados (p<0,05). Não houve diferenças significativas na marcação de Zenk em HpVL e HpVM nos diferentes grupos e nos dois horários (p>0,05). Os dois experimentos indicaram a expressão de diferentes padrões comportamentais frente ao contexto aversivo condicionado e ao som aversivo condicionado. As variações na expressão de Zenk são indicativas de ativação diferencial de HpD, HpVM e HpVL durante a evocação da memória do contexto e do som. A existência de variações dia - noite na ocorrência de condicionamento ao contexto e na expressão de Zenk no hipocampo sugere uma modulação do sistema temporizador circadiano sobre esses processos. Palavras-Chave: Condicionamento clássico aversivo; Hipocampo; Proteína Zenk; Fotoperiodo esqueleto / Abstract: Part of the knowledge about the mechanisms and neural basis of learning, memory and amnesia is based on the investigation of neural correlates of the behavior of non human animals in aversive situations. Moreover, many studies suggest that these behavioral processes are affected by the circadian timing system. The procedures of classical aversive conditioning and analysis of the conditioned freezing response are useful for the study of behavior and the underlying neural mechanisms. Previous studies showed the induction of Zenk expression in the hippocampus of pigeons after training in classical aversive conditioning. This study investigated day - night variations in the acquisition and retrieval of aversive classical conditioning and in the expression of Zenk protein in the hippocampus of pigeons. The Experiment I evaluated the conditioning to the context in pigeons attributed to conditioned (COND), control (CC) or naive groups (N). The Experiment II investigated the aversive conditioning to the tone in groups of pigeons that received toneshock pairing (PS), unpaired tone and shock (NPS) or tone alone (TS). In both experiments a photoperiod was used with pulses of light (15 min) at 6h (ZT00) and 18h (ZT12) and the sessions were conducted at ZT02 and ZT14. The results of the Experiment I indicated between group differences in the occurrence of freezing (p<0.05). A significant decrease in freezing was observed in the initial block of the test as compared to the final block of the training session of the COND ZT02 (p<0.05), but not in the COND ZT14 group (p>0.05). The analysis of the Zenk-positive nuclei in the hippocampus showed a significant increase in the HpV of the COND ZT02 group compared with the other groups (p<0.05), indicating a significant time difference when compared to COND ZT14 (p<0.05). Higher density of Zenk-positive nuclei was found in HpVM of COND ZT02 group compared to HpVL (p<0.001) and to HpVM of other groups (p<0.05). Experiment II data showed higher occurrence of exploratory risk assessment in PS and NPS groups (p>0.05) as compared to TS (P<0.5). The occurrence of freezing in the PS groups was different from TS groups (p<0,05), but not from NPS groups (p>0.05). No significant time of the day variation of freezing was detected (p> 0.05). Zenk- positive nuclei densities were higher in HpV than in HpD in the animals trained with paired or unpaired tone and shock stimulation (p <0.05). These PS and NPS groups showed no significant differences in the density of labeling of Zenk-positive nuclei in HpVL as compared to HpVM (p>0.05). Data from both experiments showed different behavioral patterns during the exposure to the conditioned aversive context and to the conditioned aversive tone. The variations in Zenk expression indicate differential activation of the HpD, HpVL and HpVM regions during retrieval of aversive memory of the context and of the tone. The day-night variation in the conditioned freezing to the context as well as in Zenk expression in the hippocampus suggests a modulation of these processes by the circadian timing system. Keywords: Classical aversive conditioning; Hippocampus; Zenk protein. Skeleton photoperiod / Universidade Estadual de Campi / Fisiologia / Mestre em Biologia Funcional e Molecular
10

Learning and Long-Term Memory Formation in Danio rerio Through Two Sensory Modalities

Morin, Christopher 01 March 2012 (has links)
The zebrafish (Danio rerio) promises to meet the growing needs of gerontological and neurobehavioral research by possessing highly conserved anatomy and physiology with all other vertebrates, while having low maintenance costs and requiring only simple care. The neurological and physiological bases of learning, memory formation, and memory retention have been studied in a variety of model organisms, such as the rat, mouse, sheep, and several teleost fishes, the notable example being the zebrafish. Unfortunately, most of these animals are poorly suited to senescence research due to costs, care requirements, or long life spans. My research expands upon our rapidly growing understanding of zebrafish neurobiology, learning processes, sensory modalities, and memory retention. Two pairs of distinct aversive conditioning experiments using classic shuttlebox designs compared the effects of sensory modality and conditioned-unconditioned stimulus (CS-US) intervals, the time delay between application of conditioned sensory stimulus and delivery of the stressful unconditioned stimulus in the event of failure to avoid it, upon memory formation and retention. These studies yielded a general spectrum of results against which future conditioning studies may be compared. Both visual and olfactory stimuli were tested, as were 10 second and 15 second CS-US intervals. Successes were scored when the fish crossed the shuttlebox hurtle within the CS-US interval, thereby avoiding the negative unconditioned stimulus. After a three-month delay, ten additional trials were conducted to compare the long-term memory retention resulting from each protocol. When testing a 15s CS-US interval, olfactory conditioning was significantly more likely (39%) to produce a successful outcome (memory formation) than visual conditioning. Grouped results reveal that the second pair of experiments, each with a 10s CS-US interval, yielded significantly more successful memory formation than a 15s CS-US interval. A significant difference was found when comparing the results of any two experiments, except between the results of the visual and olfactory 10s interval experiments). Only the olfactory experiment using a 15s CS-US interval yielded memory retention results significantly higher than the mean of memory retention results from the four experiments. These findings offer inconclusive evidence supporting olfaction’s strong role in memory formation and retention in zebrafish. The results expand our understanding of the relationship between the olfactory and visual senses and memory in the zebrafish and indicate the olfactory sense’s key role in vertebrate neurobiology, warranting further research into the effects of aging on the olfactory-memory modality.

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