Layer Specific Detection of Inhibitory fMRI Response in Somatosensory Cortex through Cortico-cortical Interaction in Rats

Introduction: There is great interest in using anatomical and functional neuroimaging techniques to understand both the topographical as well as the dynamic organization of cortical functional circuits with high spatial and temporal resolution. For example, fMRI has been used to probe the laminar flow of information [1], as well as the suppressive interaction of consecutive neuronal events in rat primary somatosensory cortices [2]. Laminar-specific cortico-cortical and thalamo-cortical projections were recently traced by manganese-enhanced MRI [3]. In the present work, we use BOLD fMRI to investigate the laminar dependence of cortico-cortical interactions induced by paired bi-lateral somatosensory stimulation in α-chloralose anesthetized rats.