MRI of Bilateral Sensorimotor Network Activation by Direct Intracortical Stimulation in Rats After Unilateral Stroke

Maurits Pieter Adriaan van Meer^1,2, Kajo van der Marel¹, Willem Maarten Otte¹, Jan Willem Berkelbach van der Sprenkel², Rick Michiel Dijkhuizen¹

Functional MRI is increasingly applied to investigate rearrangement of ipsi- and contralesional functional brain fields during recovery from stroke. However, these studies typically employ a peripheral stimulation paradigm. In this study we applied BOLD and CBV-weighted fMRI during direct intracortical stimulation (DICS) of the contralesional primary motor cortex in rats acutely after stroke in order to assess changes in central functional connectivity. DICS-fMRI enabled detection of activation responses in bilateral functional networks and we found loss of ipsilesional activation and occasional increased excitability in contralesional sensorimotor regions at 24 h after stroke.