Disuse-driven plasticity in the human thalamus and putamen

Abstract

Subcortical plasticity has mainly been studied using invasive electrophysiology in animals. Here, we leverage precision functional mapping (PFM) to study motor plasticity in the human subcortex during 2 weeks of upper-extremity immobilization with daily resting-state and motor task fMRI. We found previously that, in the cortex, limb disuse drastically impacts disused primary motor cortex functional connectivity (FC) and is associated with spontaneous fMRI pulses. It remains unknown whether disuse-driven plasticity pulses and FC changes are cortex specific or whether they could also affect movement-critical nodes in the thalamus and striatum. Tailored analysis methods now show spontaneous disuse pulses and FC changes in the dorsal posterior putamen and central thalamus (centromedian [CM], ventral-intermediate [VIM], and ventroposterior-lateral nuclei), representing a motor circuit-wide plasticity phenomenon. The posterior putamen effects suggest plasticity in stimulus-driven habit circuitry. Importantly, thalamic plasticity effects are focal to nuclei used as deep brain stimulation targets for essential tremor/Parkinson's disease (VIM) and epilepsy/coma (CM).