Olfactory learning through dopamine modulated plasticity in the fruit fly
<p>In this thesis I investigate the role of dopamine modulated plasticity during olfactory learning in the fruit fly Drosophila Melanogaster. Although previous plasticity models explore many qualitative aspects of how dopamine orchestrates plasticity that also apply to the fruit fly, no model...
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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2019
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| _version_ | 1826315509246722048 |
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| author | Menzat, B |
| author2 | Vogels, T |
| author_facet | Vogels, T Menzat, B |
| author_sort | Menzat, B |
| collection | OXFORD |
| description | <p>In this thesis I investigate the role of dopamine modulated plasticity during olfactory learning in the fruit fly Drosophila Melanogaster. Although previous plasticity models explore many qualitative aspects of how dopamine orchestrates plasticity that also apply to the fruit fly, no model explains recent relief learning and extinction experiments. In relief learning if a shock precedes an odour, the fly will learn to approach the relief signalling odour. Extinction is the disappearance of a previously learned behaviour when the behaviour is not reinforced. I address this problem by building a model that is based on the known anatomy of the fruit fly's olfactory circuit, as well as recent behavioural and imaging data in four results chapters. In chapter 2 I introduce a three-layer spiking model based on the first layers of the olfactory circuit to study the transformations of dense spatio-temporal odour patterns into sparse representations in the fly. In chapter 3 I introduce a model of the olfactory associative memory centre to study olfactory aversive learning and extinction. I show that a learning rule that doesn't require postsynaptic spikes, like in traditional models of plasticity, is sufficient to reproduce learning experiments in the fruit fly. In chapter 4 I explore appetitive learning and extinction. I hypothesize that dopaminergic neurons can inhibit each other and that suppressing the activity of a select group of dopaminergic neurons during odour exposure forms an aversive memory. In chapter 5 I investigate the role of potentiation in two experiments: relief learning and aversive re-learning. The aversive re-learning experiment shows that a fly can learn to avoid an odour, reduce its avoidance and re-learn to avoid the odour in a flexible manner depending on the absence or presence of shock in consecutive trials. I show that with potentiation re-extinction is also possible in the fly. My results provide a new perspective on dopamine-modulated learning in the fruit fly and suggest that dopamine orchestrates both potentiation and depression during plasticity.</p> |
| first_indexed | 2024-03-06T18:20:07Z |
| format | Thesis |
| id | oxford-uuid:05fe81d3-afc9-4bf0-999b-e214b8ef5980 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:27:21Z |
| publishDate | 2019 |
| record_format | dspace |
| spelling | oxford-uuid:05fe81d3-afc9-4bf0-999b-e214b8ef59802024-12-01T10:14:30ZOlfactory learning through dopamine modulated plasticity in the fruit flyThesishttp://purl.org/coar/resource_type/c_db06uuid:05fe81d3-afc9-4bf0-999b-e214b8ef5980EnglishORA Deposit2019Menzat, BVogels, T<p>In this thesis I investigate the role of dopamine modulated plasticity during olfactory learning in the fruit fly Drosophila Melanogaster. Although previous plasticity models explore many qualitative aspects of how dopamine orchestrates plasticity that also apply to the fruit fly, no model explains recent relief learning and extinction experiments. In relief learning if a shock precedes an odour, the fly will learn to approach the relief signalling odour. Extinction is the disappearance of a previously learned behaviour when the behaviour is not reinforced. I address this problem by building a model that is based on the known anatomy of the fruit fly's olfactory circuit, as well as recent behavioural and imaging data in four results chapters. In chapter 2 I introduce a three-layer spiking model based on the first layers of the olfactory circuit to study the transformations of dense spatio-temporal odour patterns into sparse representations in the fly. In chapter 3 I introduce a model of the olfactory associative memory centre to study olfactory aversive learning and extinction. I show that a learning rule that doesn't require postsynaptic spikes, like in traditional models of plasticity, is sufficient to reproduce learning experiments in the fruit fly. In chapter 4 I explore appetitive learning and extinction. I hypothesize that dopaminergic neurons can inhibit each other and that suppressing the activity of a select group of dopaminergic neurons during odour exposure forms an aversive memory. In chapter 5 I investigate the role of potentiation in two experiments: relief learning and aversive re-learning. The aversive re-learning experiment shows that a fly can learn to avoid an odour, reduce its avoidance and re-learn to avoid the odour in a flexible manner depending on the absence or presence of shock in consecutive trials. I show that with potentiation re-extinction is also possible in the fly. My results provide a new perspective on dopamine-modulated learning in the fruit fly and suggest that dopamine orchestrates both potentiation and depression during plasticity.</p> |
| spellingShingle | Menzat, B Olfactory learning through dopamine modulated plasticity in the fruit fly |
| title | Olfactory learning through dopamine modulated plasticity in the fruit fly |
| title_full | Olfactory learning through dopamine modulated plasticity in the fruit fly |
| title_fullStr | Olfactory learning through dopamine modulated plasticity in the fruit fly |
| title_full_unstemmed | Olfactory learning through dopamine modulated plasticity in the fruit fly |
| title_short | Olfactory learning through dopamine modulated plasticity in the fruit fly |
| title_sort | olfactory learning through dopamine modulated plasticity in the fruit fly |
| work_keys_str_mv | AT menzatb olfactorylearningthroughdopaminemodulatedplasticityinthefruitfly |