Spiking neural networks reach a new level
Three studies recently published within just one month by the journal Cerebral Cortex present new models of spiking networks in the brain. Electrical spikes of neurons are at the core of neural information processing. With millions of neurons and billions of synapses, the new generation of open models are powerful tools to study the complex dynamics in large networks, with implications for basic neuroscience, neuromorphic computing and AI. On EBRAINS, researchers will be able to use the large-scale neuronal network models as adaptable building blocks in their investigations and combine them with other brain simulation tools across scales.
©FZJ/SBC Lehmann
Bernstein members involved: Renato Duarte, Markus Diesmann, Claus Hilgetag, Renan Shimoura, Sacha van Albada, Alexander van Meegen
Spikes are electric impulses that a neuron can fire out to all its connected cells. These signals are key to the relay of information in the brain. The way they originate at the neurons and can be recorded with different methods, but practical limitations prevent us from being able to experimentally trace the spiking in more than a few hundred neurons simultaneously on the scale of larger networks.
New computational models with enhanced network size and complexity now give a window into phenomena that occur in interactions across large spiking networks. The mathematical models are based on abstract networks with simplified point neurons and investigated with the NEST simulator on EBRAINS. The new models expand from a previous highly detailed microcircuit model representing neuronal network of below a square millimeter of cortical surface.
The three new models reflect further cell types, larger cortical volumes and the incorporation of long-range connectivity. The full-scale models of the neuronal network in cortical tissue replicate the enormous density of connections of neurons and synapses found in nature. Network dynamics therefore can be studied at a large scale, while the behavior of the individual elements is traceable at all points.
To go even deeper, the network simulations can be connected to LFPy, a simulation engine on EBRAINS for the study of electrical fields based on highly detailed neuron models. Similarly, NEST also has an interface for co-simulation with The Virtual Brain on EBRAINS, a whole-brain network simulation engine based on mean-field models. For researchers this enables so-called multiscale investigations – spanning the macroscopic level, the large-scale network level, and the level of morphologically detailed neurons.
