Figure 5. Spaced training does not rescue long-term memory in low light conditions.

Schematic depicts experimental procedure; dark grey arenas denote low light (3 lux) conditions. Bar graphs show exploration time (as a percent of the total) for each object (mean ± SEM; n = 15). Total exploration time for each trial is indicated below the graphs. Scatter dot plots show individual discrimination ratios (open circles) and the group mean (horizontal line); positive values (>0) reflect a preference for the left-side object (familiarization trial) or the novel object (test trial). (A) Long-term memory in low light conditions was assessed 24 hours after mice were exposed to three separate familiarization trials (24 hours apart; spaced training). (B) There was no preference for object location (left or right side) in any of the familiarization trials (B_1-3). (C) During the test trial (24 hours after the last familiarization trial), mice failed to exhibit a preference for the novel object, indicating that additional exposures to the familiar object did not facilitate formation of long-term memory.