Figure 5. Three visual deprivation models.

A. Sections from adult (P56) retinas of normally reared (NR), dark-reared, rd1 and Vsx2-SE^-/- mice stained for Vsx2 (a pan-BC and Müller glia marker), Rbpms (pan-RGC marker), and Hoechst (nuclear marker).

B. Section from Vsx2-SE^−/− retina co-stained for glutamine synthetase (GS), a marker of Müller glia, and Vsx2. All Vsx2 immunoreactivity in the mutant retina is associated with Müller glia.

C. Vsx2-SE^−/− RGCs fail to respond to light. Cell-attached recordings of responses to a light step from four wild-type (WT) RGCs (two OFF-sustained and two ON-sustained) and lack of response from four Vsx2-SE^−/− RGCs. Light step for WT RGCs was adjusted to 10 R*/rod/s. Light step for Vsx2-SE^−/− RGCs was to 1000 R*/rod/s. Note that the pattern of spontaneous activity is very different between OFF and ON Vsx2-SE^−/− RGCs. R*/rod/s is the photoisomerization rate.

D. Strong synchrony between two nearby Vsx2-SE^−/− OFF RGCs. Simultaneously-recorded OFF RGCs produce highly correlated spontaneous bursts of activity. Colors indicate two different RGCs.

E. Increase in inhibitory input produces gaps in spontaneous firing. Panels show simultaneous recordings of spikes in one OFF RGC and inhibitory input in another nearly OFF RGC. Increases in inhibitory input are correlated with a decrease in spontaneous firing in the neighboring cell.

F. Inhibitory input to OFF RGCs is strongly correlated. Simultaneous recordings of spontaneous inhibitory input to two nearby OFF RGCs. The correlation coefficient for this pair was 0.8.

G. Blocking of GABA (gabazine and TPMPA) and glycine (strychnine) receptors eliminates synchrony and patterned spontaneous activity.