On this page you can find some videos generated by running SpikeFun simulations. Some of them are using quite a large numbers of neurons and synapses, typically too demanding for a average home desktop PC...
"Early Visual System" - 16.7 Million Neurons and 4 Billion Synapses
This video shows simulation of the early visual system. There are approx. 16.7 million neurons in the simulated thalamus and cortex as well as approx. 154 thousand retinal ganglion neurons (effective resolution: 320x240 pixels). Rectangle on the bottom right shows activity of the simulated retinas. This simulation starts with the completely silent thalamocortical network. Simulated retinas are fed with the natural video signal and they output their spikes to the visual thalamus in the middle of the brain. Visual thalamus relay cells then project visual signal to the visual cortex in the back of the brain. Alpha waves are clearly visible in the area of primary visual cortrex. This video is best seen in Full HD mode (to view Full HD, you would need to select 1080p resolution in the YouTube window)
"Box View" - 16.7 Million Neurons and 3.52 Billion Synapses
This simulation starts with the completely silent thalamocortical network. External current is induced in thalamocortical relay neurons that project to the visual, somatosensory and auditory cortex. This initiates prolonged network response with multiple activity clusters across the cortical surface. Simulated intracortical EEG near the end of the video shows desynchronized activity in multiple cortical regions. High-frequency spikes of inhibitory interneurons are also visible as "flicker" - the best seen in Full HD mode (to view Full HD, you would need to select 1080p resolution in the YouTube window)
Ascending Reticular Activating System Influence on the Thalamocortical Network
Simulation of the mammalian thalamocortical system with ascending activation from brainstem pedunculopontine tegmental nucleus (PPTN). This simulation also starts with the completely silent thalamocortical network. External current is induced in the PPTN neurons which have dual mode of action on thalamic neurons: excitatory on relay cells, inhibitory on reticular cells. Activation of PPTN neurons leads to increased tonic activity of relay cells and inhibition of the relay cells - which, in live animals, leads to opening of thalamic sensory "gate" towards cortex and consequent awareness.
"Wireframe View" - 2 Million Neurons and 282 Million Synapses
Similar to above, but using "wireframe" rendering mode. Each axonal branch is rendered as line where color is defined as the function of its membrane potential. Axonal tracts passing through white matter (obtained with Diffusion Spectrum Imaging - DSI) are also visualized. Network is randomly excited by inserting miniature postsynaptic potentials (mPSPs or 'minis') in the thalamic region
Copyright (C) 2012 Ivan Dimkovic. All rights reserved worldwide.