Hippocampal strata theta oscillations change their frequency and coupling during spatial learning
| Autor: | María Esther Olvera-Cortés, Blanca Erika Gutiérrez-Guzmán, J. Jesús Hernández-Pérez |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Male Spatial Learning Morris water navigation task Hippocampus Hippocampal formation Rats Sprague-Dawley 03 medical and health sciences 0302 clinical medicine Memory Coherence (signal processing) Animals Theta Rhythm Coupling Communication Behavior Animal business.industry General Neuroscience Dentate gyrus Theta oscillations 030104 developmental biology Dentate Gyrus business Psychology Neuroscience 030217 neurology & neurosurgery Stratum |
| Zdroj: | Neuroscience. 337 |
| ISSN: | 1873-7544 |
| Popis: | The theta rhythm is necessary for hippocampal-dependent spatial learning. It has been proposed that each hippocampal stratum can generate a current theta dipole. Therefore, considering that each hippocampal circuit (CA1, CA3, and Dentate Gyrus (DG)) contributes differently to distinct aspects of a spatial memory, the theta oscillations on each stratum and their couplings may exhibit oscillatory dynamics associated with different stages of learning. To test this hypothesis, the theta oscillations from five hippocampal strata were recorded in the rat during different stages of learning in a Morris maze. The peak power, the relative power (RP) and the coherence between hippocampal strata were analyzed. The early acquisition stage of the Morris task was characterized by the predominance of slow frequency theta activity and high coupling between specific hippocampal strata at slow frequencies. However, on the last training day, the theta oscillations were faster in all hippocampal strata, with tighter coupling at fast frequencies between the CA3 pyramidal stratum and other strata. Our results suggest that modifications to the theta frequency and its coupling can be a means by which the hippocampus differentially operates during acquisition and retrieval states. |
| Databáze: | OpenAIRE |
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