Research Highlight: Fast Learning with Weak Synaptic Plasticity
Long-term memory is thought to rely on the strengthening of coactive synapses. This physiological mechanism is generally considered to be very gradual, and yet new sensory stimuli can be learned with just a few presentations. ENP team leader Romain Brette and the team Computational neuroscience of sensory systems have shown theoretically that this apparent paradox can be solved when there is a tight balance between excitatory and inhibitory input. In this case, small synaptic modifications applied to the many synapses onto a given neuron disrupt that balance and produce a large effect even for modifications induced by a single stimulus. This effect makes fast learning possible with small synaptic changes and reconciles physiological and behavioral observations.
Check out the article:
Fast Learning with Weak Synaptic Plasticity. Pierre Yger, Marcel Stimberg, and Romain Brette. The Journal of Neuroscience, 30 September 2015, 35(39): 13351-13362.
Figure: Response of model neurons to a regularly repeated pattern of spikes (grey boxes), embedded in noise. After a few presentations, the neurons start to respond specifically to the pattern.