Fig. 9

Changes in sleep–wakefulness cycle at the 14th day since administration as compared to the 7th day. Proportions (normalized to day 7 after MPTP administration, 100 %) of wake time (blue bars), NREM sleep time (brown bars), and REM sleep time (green bars) during the dark 12-h period 7 and 14 days after MPTP administration. a Increased wake time and decreased NREM sleep time after MPTP administration in group 4 (N = 9); b no changes in the sleep–wakefulness cycle in group 1 mice transplanted with HEK293/mGDNF/GFP cells prior to MPTP administration (N = 9); c changes in the sleep-wake cycle in group 2 mice transplanted with HEK293/GFP cells prior to MPTP administration; d no changes in the sleep-wakefulness cycle in three mice transplanted with HEK293/mGDNF/GFP cells (N = 3), high REM sleep data dispersion is due to the low number of animals in the group. *Changes are significant at p < 0.05