Figure 2. Improvement of electroretinography (ERG) response by single AAV injection of normal mouse rhodopsin cDNA (WT Rho) in P23H transgenic mice [89]. Bars represent the average of five scotopic ERG scans at 0 dB (2.6 cd (cd)-s/m²) a-wave response. A: and b-wave response. B: at 1 month and 6 months post injection. ERG amplitudes of 1 month uninjected P23H eyes were set as 100%. A: Compared with that of corresponding contralateral eyes, injection of AAV-Rho demonstrated a significant increase in a-wave amplitudes at both 1 month (122%) and 6 months (90%) time points. (*p<0.05, n=6). B: Compared with contralateral eyes, injection of WT Rho demonstrated the same significant increase in b-wave amplitudes as that of a-wave response at both 1 month (122%) and 6 months (90%) time points. (*p<0.05, ** p<0.005, n=6). Although injection injury can induce protective cytokines such as CNTF, this effect peaks within a few days of injection and is complete before the first measurements were made.