<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Space, time and item coding in the lateral entorhinal cortex and the hippocampus"^^ . "Episodic memory formation involves encoding information about space, items and time of an experience. In\r\nhumans and animals, episodic memory formation depends on the interaction of associative areas with the\r\nhippocampus (HC) and its surrounding parahippocampal areas, in particular the entorhinal cortex (EC). The EC\r\nmedial and lateral subdivisions (MEC and LEC), harbour a plethora of spatially and item modulated cell types,\r\nrespectively. Thus, MEC and LEC were long considered specialised spatial and item coding centres, respectively,\r\nthat conveyed this information to the HC, where it was integrated into one episodic memory. In agreement\r\nwith this hypothesis, the firing of neurons in the HC is spatially modulated but is also modified by changes in\r\ncontextual and item components of an environment. However, recent studies suggest that both the MEC and\r\nLEC carry out spatial and item coding, albeit the way these elements are encoded may differ. In addition,\r\ntemporal coding in the hippocampus requires an intact MEC, however, the specific functional MEC cell types\r\ninvolved in this process are unknown. Thus, it is currently unclear how space, items and time are encoded in\r\neach of the entorhinal-hippocampal areas, and how the different entorhinal-hippocampal circuits contribute to\r\nthe transmission and association of episodic memory components. In this thesis, I explored this question from\r\nthree different angles: firstly, I characterized mechanisms of spatial and item coding in the LEC and in the CA1\r\nhippocampal area; secondly, I studied the contribution of a specific MEC-to-LEC pathway to spatial and item\r\ncoding in the LEC; thirdly, I evaluated whether the temporal coding process of phase precession in hippocampal\r\nneurons is dependent on a specific MEC functional cell type, namely grid cells. For this purpose, I performed\r\nand analysed in vivo electrophysiological recordings in freely moving mice subjected to a variety of experimental\r\nsettings, and combined this with optogenetic tagging of neurons for circuit characterisation. The findings\r\nreported in this thesis fundamentally advance our understanding of the processes underlying episodic memory\r\nencoding in several ways. First, I found that spatial selectivity in the LEC decreases along the anteroposterior\r\naxis, and that spatially modulated neurons remap when the spatial framework changes. In addition, I describe\r\ndistinct functional cell types in the LEC encoding for different object features. Importantly, spatial and object\r\ncoding neurons appear to be distinct non-overlapping neuronal populations, arguing for a separate processing\r\nof items and space in the LEC. Interestingly, object coding neurons are selectively avoided by long-range\r\nGABAergic projections from MEC to LEC. In the HC, in turn, a subset of spatially modulated neurons also encode\r\nobject-related information, suggesting that these two components of episodic memory are integrated, at least\r\nto some extent, in this region. These findings give experimental evidence to the episodic memory encoding\r\nprocess proposed by the cognitive map theory. Finally, in respect to temporal coding, I demonstrated that phase\r\nprecession is intact in the HC when grid cell firing is disrupted in the MEC, indicating that this mechanism may\r\nbe dependent on other MEC neurons and/or pathways. Together, these findings uncover new mechanisms of\r\nencoding and transmission of the three episodic memory components in the entorhinal-hippocampal circuits."^^ . "2023" . . . . . . . "Isabel"^^ . "Barriuso Ortega"^^ . "Isabel Barriuso Ortega"^^ . . . . . . "Space, time and item coding in the lateral entorhinal cortex and the hippocampus (PDF)"^^ . . . "Thesis_IBO.pdf"^^ . . . "Space, time and item coding in the lateral entorhinal cortex and the hippocampus (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Space, time and item coding in the lateral entorhinal cortex and the hippocampus (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Space, time and item coding in the lateral entorhinal cortex and the hippocampus (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Space, time and item coding in the lateral entorhinal cortex and the hippocampus (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Space, time and item coding in the lateral entorhinal cortex and the hippocampus (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #33200 \n\nSpace, time and item coding in the lateral entorhinal cortex and the hippocampus\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .