Epibatidine blocks eye-specific segregation in ferret dorsal lateral geniculate nucleus during stage III retinal waves.

The segregation and maintenance of eye-specific inputs in the dorsal lateral geniculate nucleus (dLGN) during early postnatal development requires the patterned spontaneous activity of retinal waves. In contrast to the development of the mouse, ferret eye-specific segregation is not complete at the start of stage III glutamatergic retinal waves, and the remaining overlap is limited to the C/C1 lamina of the dLGN. To investigate the role of patterned spontaneous activity in this late segregation, we disrupted retinal waves pharmacologically for 5 day windows from postnatal day (P) 10 to P25. Multi-electrode array recordings of the retina in vitro reveal that the cholinergic agonist epibatidine disrupts correlated retinal activity during stage III waves. Epibatidine also prevents the segregation of eye-specific inputs in vivo during that period. Our results reveal a novel role for cholinergic influence on stage III retinal waves as an instructive signal for the continued segregation of eye-specific inputs in the ferret dLGN.