Implications of early loss of vision on tactile discrimination and motor capabilities in Monodelphis domestica

Student Name: 
Chris Iyer
UCD Department: 
Center for Neuroscience
UCD Mentor: 
Leah Krubitzer

Loss of vision at an early developmental stage results in profound anatomical and functional alterations in the brain. These neural changes result in cross-modal cortical plasticity, the process by which the deprived cortex is co-opted or taken over by the spared sensory systems. In this study, we investigated the extent to which the neocortex of the short-tailed opossum (Monodelphis domestica) can compensate for the lack of visual input by augmenting somatosensory and motor systems. We examined behavioral correlates of this plasticity by comparing the gross and fine motor capabilities of enucleated and control opossums in a skilled reaching task. Furthermore, we explored the impact of housing conditions on the extent to which visually-deprived brains can adapt and compensate. Our results indicated that the enucleated opossums significantly outperformed the control opossums in both the light and dark conditions, and that tactilely-enriched opossums could potentially demonstrate superior motor control, likely due to enhanced tactile and olfactory capabilities. These results imply that cross-modal reorganization can not only compensate for blindness but allow the animal to outperform normal animals in some sensory-mediated behavioral tasks, offering a foothold for further research into the exact mechanisms involved in plasticity, the brain’s full capacity for remodeling, and potentially improved therapies for sensory-impaired patients.