1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China; 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
Manganese enhanced MRI (MEMRI) is capable of detecting layer specific interhemispheric somatosensory connections. In this study, Mn2+ was injected into the right visual cortex for tracing interhemispheric visual connections in normal and monocularly enucleated rats. In consistent with classic histological tracing studies, Mn2+ enhancement in the left hemisphere was concentrated within a narrow bi-laminar stripe. Upon left eye enucleation, which making the right cortex largely deprived of visual stimulation, the Mn2+ transfer dropped by 18.5%. These results for the first time demonstrated that MEMRI is capable of tracing layer-specific transcallosal connectivity of visual cortex and is sensitive to activity modulation.