Fig. 4.

Wheel running rhythm of the animals for which anatomy are presented in Figures 2 and 3. To facilitate inspection of the rhythms, the daily activity is plotted twice on a 48 hr time scale. The animals received an SCN lesion (SCN-X) at the point indicated on theleft of the actogram. Spectral analyses of the data are shown on the right of the actograms. The black vertical bars on the right of the actograms indicate the days (intact and lesioned) for which the analyses were done. A, The intact heterozygote tau mutant hamster B26-V34 had a period of 22.6 hr (days 1–12). After the partial SCN lesion, it became arrhythmic (analyses shown for days 34–74).B, The intact wild-type hamster B56-CA29 had a period of 24 hr (days 1–12). The animal became arrhythmic after a partial lesion of the SCN ablating the CaBP subnucleus (analysis shown for days 42–67).