<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Formation and Modulation of Hippocampal Ensemble Activity"^^ . "The extent to which advanced organisms can grasp and learn complex environmental patterns\r\nrepresents a fascinating feature. It is believed that memory is encoded by transiently\r\nco-active cells, so called neuronal ensembles, in which cells are temporally linked by underlying\r\nnetwork oscillations. In the hippocampus, rhythms of oscillating neuronal networks\r\nare directly associated with behavioral states. For instance, gamma rhythms are linked\r\nto memory formation, whereas intermittent sharp wave-ripple oscillations are involved in\r\nmemory consolidation.\r\nDuring coordinated neuronal ensemble activity participating cells are selectively activated\r\nalthough they are scattered throughout neuronal tissue. This spatiotemporal specificity\r\nrequires dynamic anatomical and physiological working principles. In this work, we aimed\r\nfor a deeper understanding of the apparent complexity underlying neuronal ensemble formation.\r\nWe studied the recruitment of single cells into neuronal ensembles during sharp\r\nwave-ripple oscillations in vitro. In our approach, we combined recent physiological and\r\nanatomical evidence about hippocampal principal cells. On the one hand, a subpopulation\r\nof principal cells elicits network-entrained action potentials that exhibit a characteristic ectopic\r\nwaveform in vitro. On the other hand, a large number of cells feature a peculiar axon\r\nlocation. We discovered a relationship between these two findings, showing that only cells\r\nwith axons originating from a dendrite were able to participate during sharp wave-ripple\r\noscillations.\r\nAs specific network oscillations are associated with different behavioral states, we were\r\ninterested in the modulation of network rhythms. It has been shown that enhanced levels\r\nof oxytocin affect the formation of long-lasting spatial memory. Here, we studied the effects\r\nof oxytocin on hippocampal network activity in vitro, showing that it selectively reduced\r\nsharp wave-ripples, while failing to modulate gamma oscillations.\r\nFurthermore, we investigated the neuroprotective mechanism, which is enabled by the\r\namyloid precursor protein. Although being strongly associated with Alzheimer's disease,\r\nits intracellular processing provides a basis for neuroprotection. We show that the harming\r\nimpact of a hypoxic condition on hippocampal network oscillations was eased by fragments\r\nof the amyloid precursor protein through modulation of L-type calcium channels, in vitro."^^ . "2018" . . . . . . . "Martin Erich"^^ . "Kaiser"^^ . "Martin Erich Kaiser"^^ . . . . . . "Formation and Modulation of Hippocampal Ensemble Activity (PDF)"^^ . . . "Thesis_MEKaiser_2018.pdf"^^ . . . "Formation and Modulation of Hippocampal Ensemble Activity (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Formation and Modulation of Hippocampal Ensemble Activity (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Formation and Modulation of Hippocampal Ensemble Activity (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Formation and Modulation of Hippocampal Ensemble Activity (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Formation and Modulation of Hippocampal Ensemble Activity (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #24508 \n\nFormation and Modulation of Hippocampal Ensemble Activity\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .