This thesis explores how electrical brain waves (oscillations) in two areas of a rat’s brain, the hippocampus and the prelimbic cortex, contribute to strengthening memory during sleep. It describes the oscillations during sleep and how they coordinate across different areas. Alemán-Zapatas looks at how learning, simple or complex, affects these oscillations, and how changes in the brain's ability to form new connections or the use of cannabidiol affect these sleep processes.
First, the thesis shows that when hippocampal oscillations are electrically disrupted during sleep, or when sleep is avoided after learning, long-term memories don’t consolidate properly. The researcher also found that increasing the prelimbic cortex's ability to form connections made recent simple memories more prominent but interfered with complex memories. Furthermore, it was discovered that when rats were given cannabidiol, they slept longer but had fewer long-duration hippocampal oscillations. As a result, their ability to consolidate complex memories worsened, though they could still remember simple memories.
Finally, Alemán-Zapatas proposes a way to classify different types of hippocampal oscillations during sleep. Using this classification, I describe specific patterns of brain activity between the prelimbic cortex and hippocampus. These patterns help consolidate simple or complex memories.
Adrián Alemán-Zapata was born in Aguascalientes, Mexico in 1990. He studied biomedical engineering at the University of Guadalajara. During his bachelor’s, he interned at various institutions: UNAM, UNB, UT Dallas and Auckland Bioengineering Institute. He later pursued a master’s degree in electrical engineering at TU Eindhoven. He completed his master’s thesis at the Donders Institute.
In November 2019, Adrián joined the Genzel lab as a junior researcher and later became a PhD candidate, focusing on analyzing rat electrophysiological signals during NonREM sleep. He has supervised over thirty students, set up data pipelines, organized virtual computational seminars, and managed data storage. In the summer of 2022, he completed a secondment at the Instituto Cajal in Madrid, studying neuronal oscillations and dimensionality reduction. Adrián has presented his work at major neuroscience conferences in Europe and the US.