Imaging interhemispheric interac ons in normal and monocularly deprived young visual cortex by manganese-enhanced magne c resonance imaging

This study employed in vivo high resolu on manganese-enhanced magne c resonance imaging (MEMRI) to inves gate interhemispheric interac ons in normal and monocularly deprived visual cortex of rats with unimpaired vision, le or right eyelid suturing, or le or right eye enuclea on. A er seven days with altered vision, the animals were injected with manganese ions into the right visual cortex and imaged with an inversion-recovery modified driven-equilibrium Fourier transform sequence. The results showed prominent manganese transport, via the splenium of the corpus callosum, to the le hemisphere where the signal enhancement peaked on the border of the primary/secondary visual cortex and expanded medial-laterally with layer specificity. Significant decrease of transcallosal manganese labeling of the le hemisphere was observed a er le eyelid suturing, le eye enuclea on, and right eyelid suturing but not right eye enuclea on, sugges ng that the adult brain recruits different mechanisms for adapta on under different circumstances. Our findings demonstrated MEMRI as an efficient tool for inves ga ng interhemispheric interac ons both anatomically and func onally.