Table 2. Electroretinographic analysis of 8-month-old wt/wt and Stgd3/wt mice

Electroretinographic parameters were derived from analysis of rod and cone electroretinograms (representative electroretinograms see Figure 4). Shown in this table are the values for rod amplitude obtained using single blue flash (-0.5 log scot td/s) and for cone amplitude obtained using single white flash on a rod-saturating background. To calculate the maximal rod response (Rmp3) and the amplification constant (S), the leading edge of the a-waves was fit as an ensemble [53] using the Lamb and Pugh model [54] for the activation phase of the phototransduction cascade. Values are means±standard deviation. Six mice were analyzed per group.

     Variable          wt/wt     Stgd3/wt   Significance
-------------------   --------   --------   ------------
Rod amplitude (μV)     164±33     100±19      p<0.002
Cone amplitude (μV)     63±22      44±10      p<0.09
Rmp3 (μV)              134±21      85±20      p<0.003
S                       98±26     105±28      p<0.62