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. Author manuscript; available in PMC: 2015 Jun 8.
Published in final edited form as: Science. 2014 Nov 14;346(6211):854–857. doi: 10.1126/science.1259652

Fig. 2. An intact SCN is necessary for circadian arrhythmia to impair recognition and spatial memory.

Fig. 2

(A) Representative actograms of DPS (top) and SCNx (bottom) animals; red triangle indicates day of treatment. Chi-square periodograms confirm robust rhythms during entrainment (blue peaks above black line are significant; P = 0.001) and arrhythmia. (B) SCNx animals (n = 11) performed significantly better than random chance (i.e., 50 for SA, 0 for NOR), whereas DPS-treated animals (n = 8) failed both memory tests (upper panels). ENT (n = 10) and sham-operated (SHAM) (n = 11) hamsters also performed significantly better than chance. Arrhythmic groups shown in blue. Scores significantly different from chance indicated by * (one-sample t test; 0.0001 < P < 0.01). For DPS animals, P > 0.05. Number of T-maze arm entries and NOR exploration times did not differ significantly among ENT, DPS, SCNx, and SHAM groups (P > 0.05; middle panels). No left-right positional biases were found in the Tmaze or NOR arena (P > 0.05; lower panels) (22). (C) Representative Nissl-stained tissue sections from intact (left) and SCNx (right) hamsters. Optic tracts are labeled OT. Black scale bar, 100 μm.