Modelling synaptic and intrinsic plasticity in primate somatosensory cortex (360G-Wellcome-209998_Z_17_Z)

Somatosensory plasticity is as key ingredient of sensorimotor learning; a better understanding of the plasticity mechanisms involved would yield insights for neuroprosthetics, motor rehabilitation, and chronic pain. In the somatosensory cortex, changes in the hand representation have been described under stimulation paradigms lasting only a few hours. Conversely, other evidence shows that cortical representations are stable over long periods of time. These disparate results raise the question of whether different plasticity mechanisms, operating on different timescales, might be involved. Recent advances in neuroimaging techniques have allowed us to observe and track plasticity in the human brain, leading to novel insights into the timescale and extent of sensorimotor learning. However, inferring specific plasticity mechanisms from these data has been challenging, as observed cortical changes are often compatible with multiple mechanisms. Here, we focus on two forms of plasticity: synaptic plasticity, which determines which specific inputs will excite a cortical neuron, and intrinsic plasticity, which determines the neuron’s overall responsiveness. We propose a computational framework that will track the effects of these two mechanisms on sensory cortical representations and make predictions that can be empirically tested using existing fMRI paradigms.