Cortical network reorganization of congenital and perinatal blindness in mice

Cross-modal recruitment of visual cortical areas by auditory and somatosensory stimulation have often been reported in early blind humans. However, lower resting-state functional connectivity (rsFC) between visual and somatosensory and auditory cortical areas and weaker interhemispheric rsFC have been reported in blind humans. Moreover, rsFC is more variable in blind individuals than in sighted controls. Cross-modal recruitment of visual cortical areas has also been shown in mice. Cross-modal activation involves modifications of the excitatory/inhibitory balance, rather than establishing new connections between sensory modalities. We used mesoscopic calcium imaging in sighted and visually deprived mice (neonatal binocular enucleation or congenital anophthalmia) to investigate cortical rsFC derived from the activity of all cortical neuronal populations (AAV.PhP.eB-hSyn-GCaMP6s), or distinctly from glutamatergic (Thy1-GCaMP6s tg-mice), or GABAergic (AAV.PhP.eB-mDLX-GCaMP6s) neuronal population. Graph analysis on rsFC shows subtle modifications in the cortical network. Our observations suggest strain differences in plasticity following vision deprivation. While the global network metrics remain relatively unaltered, analysis of individual nodes reveals a reduced influence of the primary visual cortex and contrasting effects on medial (PM, AM and A) compared to lateral (AL, LM and LI) extrastriate visual cortices as well as between the lemniscal (HL, FL and TR) and trigeminal (BC, NO and MO) related somatosensory cortices. In conclusion, these findings shed light on the contribution of specific neuronal populations and strain-specific variations in cortical plasticity to the intricate dynamics of RSFC in response to visual deprivation on cortical sensory networks.