Figure 2: Graphs showing (a) the areas and (b) the number of TH+ amacrine cells in the retinae in the four experimental groups in the different cases (different shaded columns). Columns show the mean ± standard error of the total number of cells in each case. Represents 𝑃 < 0 . 0 0 1 , represents 𝑃 < 0 . 0 1 and *represents 𝑃 < 0 . 0 5 significant difference in cell number; these symbols on the columns of the MPTP group represent differences from the Saline group of each case, while symbols on the MPTP-NIr group represent differences from the MPTP group of each case. There were clear increases in TH+ cell number in the MPTP-NIr group compared to the MPTP group in all cases, particularly the Ac-PT, Ch-Sim, and Ch-PT.