Graphs showing the results of behavioural analysis of Balb/c (A,B,C) or C57BL/6 (A’,B’,C’) mice. The behavioural analysis included the locomotor activities of velocity (A,A’), high mobility (B,B’) and immobility (C,C’). Columns show the mean ± standard error of each group; black columns show results for MPTP groups, while grey columns show results for MPTP-NIr groups. There were ten animals per group. The asterisks (*) within the MPTP-NIr columns (A,B,C) represent p<0.05 level of significant difference in number from the MPTP group. The locomotor activity in the Saline and Saline-NIr groups were very similar in both strains; their values were pooled and represented as a dotted line across each of the graphs. Each animal was tested at four time points; (T1) after first MPTP or saline injection and NIr (or no) treatment; (T2) after second NIr (or no) treatment; (T3) after second MPTP or saline injection and third NIr (or no) treatment; (T4) after fourth NIr (or no) treatment.