Computer simulation of memory cells

As part of a transnational funding initiative entitled ‘German–US Collaboration in Computational Neuroscience’, Stefan Remy, a scientist at the German Centre for Neurodegenerative Diseases (DZNE), and his colleagues Nelson Spruston and Bill Kath of Northwestern University and Stephen Smith of Stanford University have received US$1.5 million in funding to research neuronal memory function.

The project will be funded over three years by the National Institute of Health (NIH) and the German Federal Ministry of Education and Research (BMBF). The aim of the project is to improve understanding of neuronal connections in the hippocampus. The hippocampus is a region in the temporal lobes of the brain that is particularly important for learning and memory. Scientists believe that signal transmission by nerve cells and their functional connections are altered in many diseases of the nervous system, such as Alzheimer’s disease, epilepsy and schizophrenia.

All brain activities – sensory perception, thinking, remembering – are based on the electrical activity of nerve cells. Electrical signals are transmitted from cell to cell at their points of contact, the synapses. As part of the project funding, Remy and his colleagues will develop realistic computer models of individual nerve cells and will use these models to simulate the complex interactions between nerve cells in networks. Such computer simulations are essential to improve our understanding of the cognitive functions of the brain and their malfunction in neurodegenerative diseases.

Nerve cells send long, finely branched extensions, or dendrites, into neighbouring brain regions. A nerve cell receives and processes electrical signals at around 50,000 synapses – neuronal contact points – from upstream cells. To develop a realistic model of nerve cell function, it is important to know the precise distribution of the synapses on the branched neuronal structures. Yet additional factors also play an essential role in signal processing, such as the strength of the synaptic contact or the diameter of the dendrite at the contact point. Remy and his colleagues will study these factors using new methods with a degree of precision not previously achieved. The function of the synapses will be studied using targeted laser pulses which can trigger the release a neurotransmitter, glutamate, from single or multiple synapses. The scientists will also analyse the structure of nerve cells, including all of their branching and synapses, using ultra-modern microscopy and tomography techniques. By using improved computer models that take all relevant functional factors into consideration, researchers hope to generate new hypotheses about brain function which can then be tested experimentally. The researchers will also study how the synaptic strength changes over time. Change in synaptic connections due to neuronal activity, also known as neuroplasticity, is correlated with learning and memory and is often impaired in neurodegenerative diseases.

Contact information:
Dr Stefan Remy
Research Group Leader
German Centre for Neurodegenerative Diseases (DZNE)
c/o University Hospital Bonn
Sigmund-Freud-Strasse 25
53105 Bonn
Germany
E-mail: stefan.remy@dzne.de
Tel.: +49 (0) 228 / 28751-605
Dr Katrin Weigmann
Media and Public Relations Officer
German Centre for Neurodegenerative Diseases (DZNE)
Holbeinstrasse 13–15
53175 Bonn
Germany
E-mail: katrin.weigmann@dzne.de
Tel.: +49 (0) 228 / 43302 263
Mobile: +49 (0) 173 547 1350