That experiences leave their trace in the connectivity of the brain has been known for a while, but a pioneering study by researchers at DZNE and TUD Dresden University of Technology now shows how massive these effects really are. The findings in mice provide unprecedented insights into the complexity of large-scale neural networks and brain plasticity. Moreover, they could pave the way for new brain-inspired artificial intelligence methods. The results, based on an innovative “brain-on-chip” technology, are published in the scientific journal “Biosensors and Bioelectronics”.

The Dresden researchers explored the question of how an enriched experience affects the brain’s circuitry. For this, they deployed a so-called neurochip with more than 4,000 electrodes to detect the electrical activity of brain cells. This innovative platform enabled registering the “firing” of thousands of neurons simultaneously. The area examined – much smaller than the size of a human fingernail – covered an entire mouse hippocampus. This brain structure, shared by humans, plays a pivotal role in learning and memory, making it a prime target for the ravages of dementias like Alzheimer's disease. For their study, the scientists compared brain tissue from mice, which were raised differently. While one group of rodents grew up in standard cages, which did not offer any special stimuli, the others were housed in an “enriched environment” that included rearrangeable toys and maze-like plastic tubes.

“The results by far exceeded our expectations,” said Dr. Hayder Amin, lead scientist of the study. Amin, a neuroelectronics and computational neuroscience expert, heads a research group at DZNE. With his team, he developed the technology and analysis tools used in this study. “Simplified, one can say that the neurons of mice from the enriched environment were much more interconnected than those raised in standard housing. No matter which parameter we looked at, a richer experience literally boosted connections in the neuronal networks. These findings suggest that leading an active and varied life shapes the brain on whole new grounds.”

Unprecedented Insight into Brain Networks

Prof. Gerd Kempermann, who co-leads the study and has been working on the question of how physical and cognitive activity helps the brain to form resilience towards aging and neurodegenerative disease, attests: “All we knew in this area so far has either been taken from studies with single electrodes or imaging techniques like magnetic resonance imaging. The spatial and temporal resolution of these techniques is much coarser than our approach. Here we can literally see the circuitry at work down to the scale of single cells. We applied advanced computational tools to extract a huge amount of details about network dynamics in space and time from our recordings.”

“We have uncovered a wealth of data that illustrates the benefits of a brain shaped by rich experience. This paves the way to understand the role of plasticity and reserve formation in combating neurodegenerative diseases, especially with respect to novel preventive strategies,” Prof. Kempermann said, who, in addition to being a DZNE researcher, is also affiliated with the Center for Regenerative Therapies Dresden (CRTD) at TU Dresden. “Also, this will help provide insights into disease processes associated with neurodegeneration, such as dysfunctions of brain networks.”

Potential Regarding Brain-inspired Artificial Intelligence

By unraveling how experiences shape the brain’s connectome and dynamics, we are not only pushing the boundaries of brain research,” states Dr. Amin. “Artificial intelligence is inspired by how the brain computes information. Thus, our tools and the insights they allow to generate could open the way for novel machine learning algorithms.”

Original Publication:
Brett Addison Emery, Xin Hu, Shahrukh Khanzada, Gerd Kempermann, Hayder Amin: High-resolution CMOS-based biosensor for assessing hippocampal circuit dynamics in experience-dependent plasticity.
Biosensors and Bioelectronics (2023)
Link: https://doi.org/10.1016/j.bios.2023.115471

About the Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE (German Center for Neurodegenerative Diseases):
DZNE is a research institute funded by the German federal and state governments, comprising ten sites across Germany. It is dedicated to diseases of the brain and nervous system, such as Alzheimer’s, Parkinson’s, and ALS, which are associated with dementia, movement disorders and other serious health impairments. To date, there are no cures for these diseases, which represent an enormous burden for countless affected individuals, their families, and the healthcare system. The aim of DZNE is to develop novel strategies for prevention, diagnosis, care, as well as treatment, and to transfer them into practice. To this end, DZNE cooperates with universities, university hospitals, research centers and other institutions in Germany and abroad. The institute is a member of the Helmholtz Association and belongs to the German Centers for Health Research. www.dzne.de/en

About the Center for Regenerative Therapies Dresden (CRTD)
The Center for Regenerative Therapies Dresden (CRTD) of TU Dresden is an academic home for scientists from more than 30 nations. Their mission is to discover the principles of cell and tissue regeneration and leverage this for the recognition, treatment, and reversal of diseases. The CRTD links the bench to the clinic, scientists to clinicians to pool expertise in stem cells, developmental biology, gene-editing, and regeneration towards innovative therapies for neurodegenerative diseases such as Alzheimer's and Parkinson's disease, hematological diseases such as leukemia, metabolic diseases such as diabetes, bone and retina diseases.
The CRTD was founded in 2006 as a research center of the German Research Foundation (DFG) and funded until 2018 as a DFG Research Center, as well as a Cluster of Excellence. Since 2019, the CRTD is funded by the TU Dresden and the Free State of Saxony.
The CRTD is one of three institutes of the central scientific facility Center for Molecular and Cellular Bioengineering (CMCB) of the TU Dresden.
Web: www.tu-dresden.de/cmcb/crtd
Web: www.tu-dresden.de/cmcb

Resources:
Full resolution pictures: https://tud.link/eoki

Scientific contact:
Prof. Gerd Kempermann
Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)
Center for Regenerative Therapies Dresden (CRTD)
Tel: +49 351 210 463-700