Fig. 3.

Effects of SIV infection on the circadian rhythm of activity. (A, C, and E) In uninfected monkeys, the amplitude (A), MESOR (C), and acrophase (E) did not show significant changes along the study. (B, D, and F) For the SIV-infected monkeys, the amplitude (B) and MESOR (D) of locomotor activity circadian rhythm showed significant alterations during the progression of the disease to SIVE; the acrophase (F) did not. Stages were matched between the uninfected and SIV-infected groups, as described in the legend to Fig. 1. Each point represents the mean values (± SEM) of a 24-h period. Asterisks indicate significant differences compared with the preinfection stage (P ≤ 0.01); n = 5 in each group.