Correlational structure of spontaneous neuronal activity in the developinglateral geniculate nucleus in vivo

The properties of spontaneous activity in the developing visual pathway bey ond the retina are unknown. Multielectrode recordings in the lateral genicu late nucleus (LGN) of awake behaving ferrets, before eye opening, revealed patterns of spontaneous activity that reflect a reshaping of retinal drive within higher visual stages. Significant binocular correlations were presen t only when corticothalamic feedback was intact. In the absence of retinal drive, cortico-thalamic feedback was required to sustain correlated LGN bur sting. Activity originating from the contralateral eye drove thalamic activ ity far more strongly than that originating from the ipsilateral eye. Thus, in vivo patterns of LGN spontaneous activity emerge from interactions betw een retina, thalamus, and cortex.