Fig. 2
From: Photoperiod, food restriction and memory for objects and places in mice
(A) Graphical representation of the Novel Object Preference test of long-term (24 h) object memory. Memory for the familiar of two objects is inferred from the Discrimination Index (DI, the fraction of total object exploration time spent exploring the novel object). Individual and group mean (± SEM) DI scores and exploration times are presented for each of 4 test times and averaged across test times (D,G), with food available ad-libitum (B,E) and restricted to a 4 h daily meal (C,F). In panels B and C, stars denote DI scores significantly greater than chance (1-sample t-tests, p < 0.05). In panels (D–G), stars denote differences between the long-day and short-day groups. Test times are denoted using Zeitgeber Time (ZT) and External Time (ExT) notation. Yellow and grey shading denotes lights-on or -off at each test time. Food restriction increased object exploration (G) but not the DI score (D).
