Publicação
Homeostatic plasticity induced by brief activity deprivation enhances long-term potentiation in the mature rat hippocampus
| Resumo: | At the nervous system Homeostatic plasticity monitors and maintains neuronal activity within a functional range, whereas Long-term potentiation (LTP) modifies the relative strength of specific synapses in response to discrete changes in activity and is thought to provide the cellular basis of learning and memory. This work assessed whether Homeostatic plasticity could influence subsequent LTP in acute hippocampal slices that had been briefly deprived of activity. Brief activity deprivation was induced by blocking evoked and spontaneous glutamatergic transmission for 3h. Changes in the threshold for LTP were evaluated by inducing LTP with stimulation protocols of decreasing strength. We found that stimulation with a single train was able to induce LTP in activity deprived slices but not under control conditions. LTP saturation was assessed through the delivery of three consecutive 60 minute LTP protocols, using stronger protocols. The magnitude of the first LTP was increased in activity deprived slices independently of the protocol and this difference was maintained at the end of the third LTP, suggesting a raised “ceiling” for LTP. It is concluded that even brief periods of altered activity in fully developed hippocampal circuits are able to shape subsequent synaptic transmission and Hebbian plasticity. |
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| Autores principais: | Oliveira, Afonso José Costa Félix de |
| Assunto: | Plasticidade homeostática Potenciação de longo termo (LTP) Memória |
| Ano: | 2014 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | At the nervous system Homeostatic plasticity monitors and maintains neuronal activity within a functional range, whereas Long-term potentiation (LTP) modifies the relative strength of specific synapses in response to discrete changes in activity and is thought to provide the cellular basis of learning and memory. This work assessed whether Homeostatic plasticity could influence subsequent LTP in acute hippocampal slices that had been briefly deprived of activity. Brief activity deprivation was induced by blocking evoked and spontaneous glutamatergic transmission for 3h. Changes in the threshold for LTP were evaluated by inducing LTP with stimulation protocols of decreasing strength. We found that stimulation with a single train was able to induce LTP in activity deprived slices but not under control conditions. LTP saturation was assessed through the delivery of three consecutive 60 minute LTP protocols, using stronger protocols. The magnitude of the first LTP was increased in activity deprived slices independently of the protocol and this difference was maintained at the end of the third LTP, suggesting a raised “ceiling” for LTP. It is concluded that even brief periods of altered activity in fully developed hippocampal circuits are able to shape subsequent synaptic transmission and Hebbian plasticity. |
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