Abstract
Purpose :
Retinal ganglion cells (RGCs) transmit signals to various brain regions to drive both conscious and subconscious visual behaviors. In the primary pathway for conscious perception, RGCs innervate thalamocortical cells in the dorsal lateral geniculate nucleus (dLGN). During development, these connections undergo significant refinement and previous work in mice has shown that this process is disrupted in the absence of visual experience between postnatal days (P) 20-30. While it is clear that visual experience is required for proper refinement, it is still unknown whether experience can also play an instructive role.
Methods :
To test whether experience instructs retinogeinculate refinement, we utilized a selective-experience rearing (SER) paradigm, which involves restricting the visual experience of mice. After SER, we measured the tuning properties of dLGN neurons by in vivo electrophysiological recordings from the dLGN in anesthetized mice.
Results :
If visual experience has an instructive influence, we would expect the representation of salient features to be altered. Indeed, when mice were selectively exposed to horizontal gratings stimuli moving upward between P20-30, representation for this stimulus increased in the dLGN. These alterations are not due to changes in corticothalamic feedback because when we acutely silence the visual cortex during our recordings, these SER-dependent alterations persist. Moreover, these SER-dependent changes are absent in mutant mice that exhibit disruptions in retinogeniculate refinement.
Conclusions :
These results suggest that the experience-dependent phase of retinogeniculate refinement is important for fine-tuning visual circuits to respond to environmentally relevant features.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.