Figure 2.

Experimentally increased spontaneous retinal activity before eye opening drives a reduction in geniculate receptive field size before visual experience. a, 2D Gaussian fits from representative receptive fields of ferrets treated with intraocular injections of the mGluR6 antagonist CPPG (2 mm) (top row) or a combination of TPMPA (2 mm), gabazine (200 μm), and strychnine (20 μm) [TGS] (bottom row) from P15–P25 are shown from the second postnatal month of development. Scale bars indicate the width of 1 visual degree relative to the size of the receptive fields. b, c, Developmental refinement of geniculate receptive field sizes in CPPG- and TGS-treated ferrets, respectively. Box-and-whisker plots are formatted the same as in Figure 1. There is no difference between the two treatment groups. d, Box-and-whisker plot illustrating the significant difference between receptive field sizes of saline-treated ferrets and both CPPG- and TGS-treated ferrets at eye opening (***p < 0.001).