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. 2014 Jan 23;9(1):e86240. doi: 10.1371/journal.pone.0086240

Figure 5. MPTP-treated monkeys maintain 24 h hormonal rhythms of melatonin and cortisol in both entrained (LD) and constant conditions (LL).

Figure 5

Representative individual 24(dual harmonic regression fit) of urinary concentration of 6 sulphatoxymelatonin (red circles, line) and cortisol (green circles, line) compared to the mean relative activity profile (black line). Gray shading indicates the dark phase. In LD, controls and MPTP-treated animals show clear rhythms of locomotor activity, aMT6s and cortisol (A, C, E). In LL, control (B), rhythmic (D) and arrhythmic (F) MPTP animals also show a clear circadian rhythmicity of aMT6s and cortisol. The times of the aMT6s and cortisol peaks (G), the phase angles of aMT6s to both cortisol and activity rhythms (H) and the amplitudes of aMT6s and cortisol rhythms (I) were similar in LD and LL in both controls and MPTP-treated subjects (controls n = 4; MPTP n = 3).