![]() ![]() ![]() ![]() In the mouse visual system, there are numerous types of cells that encode information in specific ways at each step of the visual pathway. Information is integrated at various stages of this pathway to generate complex response properties in neurons throughout the visual pathway that help give rise to visual perception and behavior ( Douglas and Martin, 2004). The neural circuits that subserve vision originate in the retina where visual information is conveyed by retinal ganglion cells (RGCs) first to the dorsal lateral geniculate nucleus (dLGN) of the thalamus, then to neurons in specific layers of the primary visual cortex (V1). Altogether, these results suggest that direction and orientation tuning of V1 neurons may be at least partly inherited from parallel pathways originating in the retina. Strikingly, a subset of the RGCs had tuning properties that matched the direction and orientation tuning properties of the L4 V1 neurons to which they provided input. We find significant differences in the tuning of Nr5a1-Cre versus Scnn1a-Tg3-Cre neurons for direction, orientation, spatial frequency, temporal frequency, and speed. RGCs providing input to these neurons (via LGN) were labeled and characterized using Cre-dependent trans-synaptic retrograde labeling with G-deleted rabies virus. Visual tuning properties of L4 V1 neurons were evaluated using Cre-dependent expression of GCaMP6s followed by 2-photon calcium imaging. Here, we explored the relationships between functional properties of L4 V1 neurons and their RGC inputs by taking advantage of two Cre-expressing mouse lines - Nr5a1-Cre and Scnn1a-Tg3-Cre - that each label functionally and anatomically distinct populations of L4 neurons. However, the much larger number of retinal ganglion cell (RGC) types that project to the LGN, as well as the more limited lamination of both the LGN and the thalamocortical-recipient layer 4 (L4) in mice, leaves considerable uncertainty about which visual features present in both retina and V1 might be inherited from parallel pathways versus extracted by V1 circuits in the mouse visual system. ![]() Parallel functional and anatomical visual pathways from the retina to primary visual cortex (V1) via the lateral geniculate nucleus (LGN) are common to many mammalian species, including mice, carnivores and primates. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |