Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros

Base de dados
Ano de publicação
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 617(7962): 777-784, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37100911

RESUMO

Associating multiple sensory cues with objects and experience is a fundamental brain process that improves object recognition and memory performance. However, neural mechanisms that bind sensory features during learning and augment memory expression are unknown. Here we demonstrate multisensory appetitive and aversive memory in Drosophila. Combining colours and odours improved memory performance, even when each sensory modality was tested alone. Temporal control of neuronal function revealed visually selective mushroom body Kenyon cells (KCs) to be required for enhancement of both visual and olfactory memory after multisensory training. Voltage imaging in head-fixed flies showed that multisensory learning binds activity between streams of modality-specific KCs so that unimodal sensory input generates a multimodal neuronal response. Binding occurs between regions of the olfactory and visual KC axons, which receive valence-relevant dopaminergic reinforcement, and is propagated downstream. Dopamine locally releases GABAergic inhibition to permit specific microcircuits within KC-spanning serotonergic neurons to function as an excitatory bridge between the previously 'modality-selective' KC streams. Cross-modal binding thereby expands the KCs representing the memory engram for each modality into those representing the other. This broadening of the engram improves memory performance after multisensory learning and permits a single sensory feature to retrieve the memory of the multimodal experience.


Assuntos
Encéfalo , Percepção de Cores , Drosophila melanogaster , Aprendizagem , Memória , Neurônios , Percepção Olfatória , Animais , Encéfalo/citologia , Encéfalo/fisiologia , Dopamina/metabolismo , Aprendizagem/fisiologia , Corpos Pedunculados/citologia , Corpos Pedunculados/fisiologia , Neurônios/fisiologia , Drosophila melanogaster/citologia , Drosophila melanogaster/fisiologia , Neurônios GABAérgicos/metabolismo , Neurônios Serotoninérgicos/metabolismo , Memória/fisiologia , Percepção Olfatória/fisiologia , Neurônios Dopaminérgicos/metabolismo , Inibição Neural , Percepção de Cores/fisiologia , Odorantes/análise
2.
Curr Biol ; 31(16): 3490-3503.e3, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34146482

RESUMO

Prior experience of a stimulus can inhibit subsequent acquisition or expression of a learned association of that stimulus. However, the neuronal manifestations of this learning effect, named latent inhibition (LI), are poorly understood. Here, we show that prior odor exposure can produce context-dependent LI of later appetitive olfactory memory performance in Drosophila. Odor pre-exposure forms a short-lived aversive memory whose lone expression lacks context-dependence. Acquisition of odor pre-exposure memory requires aversively reinforcing dopaminergic neurons that innervate two mushroom body compartments-one group of which exhibits increasing activity with successive odor experience. Odor-specific responses of the corresponding mushroom body output neurons are suppressed, and their output is necessary for expression of both pre-exposure memory and LI of appetitive memory. Therefore, odor pre-exposure attaches negative valence to the odor itself, and LI of appetitive memory results from a temporary and context-dependent retrieval deficit imposed by competition with the parallel short-lived aversive memory.


Assuntos
Comportamento Apetitivo , Drosophila , Aprendizagem , Animais , Neurônios Dopaminérgicos/fisiologia , Drosophila/fisiologia , Memória , Corpos Pedunculados/fisiologia , Odorantes , Olfato
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA