Relationship of correlated spontaneous activity to functional ocular dominance columns in the developing visual cortex.

Utilizing a multielectrode array to record spontaneous and visually evoked activity of cortical neurons in area 17, we investigate the relationship between long-range correlated spontaneous activity and functional ocular dominance columns during early ferret postnatal development (P24-P29). In regions of visual cortex containing alternating ocular dominance patches, periodic fluctuations in correlated activity are observed in which spontaneous activity is most highly correlated between cortical patches exhibiting the same eye preference. However, these fluctuations are present even within large contralateral eye-dominated bands which lack any periodic alternations in ocular dominance. Thus, the organization of ocular dominance columns cannot fully account for the patterns of correlated activity we observe. Our results suggest that patterns of long-range correlated activity reflect an intrinsic periodicity of cortical connectivity that is constrained by segregated eye-specific LGN afferents.