Spatial navigation and memory are essential components of our daily lives. Without these talents, we would have difficulty navigating our surroundings and remembering past experiences. However, the neural foundations of spatial memory are less known.
A study group directed by Professor Lucas Kunz, who has recently joined the University Hospital Bonn (UKB), has discovered fresh information on this knowledge gap. He, together with scientists from New York and Freiburg, discovered that during spatial memory different types of nerve cells become active simultaneously and are coordinated by brain waves (“ripples”). The findings have now been published in the journal Nature Neuroscience.
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Associative memory allows different pieces of information to be linked together.
“In the context of spatial memory, associative memory enables us to remember the locations of certain objects in a spatial environment,” explains Professor Kunz, leader of the cognitive and translational neuroscience research group in the Department of Epileptology at UKB. He is also a member of the Transdisciplinary Research Area (TRA) “Life and Health” at the University of Bonn. “For example, we can remember where in the house we put our keys”. However, in advanced age or in certain diseases such as Alzheimer’s, this ability is limited. “It is therefore important to investigate the neuronal basis of different forms of human memory,” Professor Kunz said. In the long term, this could help develop new treatments for memory loss.
Nerve cells remain active when retrieving information from memory. To further investigate this phenomenon, the researchers recorded the activity of individual nerve cells that perform memory functions in epilepsy patients. “In the virtual world, participants were asked to remember the locations of various objects,” explains Professor Kunz.
The recordings revealed that different types of nerve cells became active during this memory task. Some nerve cells respond to certain objects, while other nerve cells activate in response to certain places. The scientists observed that when participants remembered the right object in the right place, the interactions between different types of nerve cells became stronger over time.
In addition to place and object neurons, researchers observed hippocampal brain waves (“ripples”) that also occurred during a memory task, possibly playing an important role in the formation and retrieval of associative memories. Professor Kunz explains, “The waves may be important for the connections of different types of nerve cells and the formation of complex memories. It will be exciting to investigate this idea further in future studies.” It would also be interesting to study how memory performance is regulated when waveforms are suppressed or triggered, thereby providing insight into the contextual relevance of waveforms.
Professor Kunz intends to continue the findings he obtained with his colleagues at the University of Freiburg in the School of Engineering and Applied Science at Columbia University in New York and the University Hospital Bonn.
“The Department of Epilepsy Science at UKB is renowned for its excellent brain research. The department has the unique opportunity to record the activity of individual nerve cells in the human brain in a video EEG monitoring unit, which is central to every epilepsy centre. This human brain It provides exciting insights into the functioning of the brain, which is only possible in a few research centers worldwide,” describes Professor Kunz.
In his interdisciplinary research, he builds close exchanges with other researchers and medical doctors, which is essential for the development of new research ideas.
