A role for the pulvinar following early life lesions of V1

Conscious vision is believed to depend upon an intact primary visual cortex (V1).  However, injury to V1 in early life often results in the preservation of visual capacity.

Apart from V1, the middle temporal area (MT) also receives retinal input via the koniocellular (K) layers of the lateral geniculate nucleus (LGN) and the medial portion of the inferior pulvinar (PIm) of the thalamus. Following permanent lesions of primate V1 in early and adult life, we examined the potential of these pathways to provide the neural substrate for maintaining vision. Combining diffusion MRI and neural tracing, we demonstrated that a lesion of V1 in young but not adult animals prevented the normal age-dependent pruning of the retina-pulvinar-MT pathway while the retina-LGN-MT pathway was not altered. This implies that age-dependent plasticity of the retina-pulvinar-MT pathway could be the substrate that supports visual function after a lesion of V1 in early life.