Fig. 1

Experimental design. A At postnatal day 9 (P9), \(\text{ER}\alpha\)^+/+ and \(\text{ER}\alpha\)^−/− male and female mice were exposed to HI mice were either treated with DHF or VC starting 10 min from the HI for 7 days. Mice were assessed with the NOR and NOL tests starting at P60 + , one week apart. Their brains were then perfused fixed at P90 + for IHC staining. B Behavioral testing timeline. Prior to behavioral testing, mice were acclimated to the housing and their cages for two days (red). Each test block consisted of acclimation (red), handling (orange), habituation (green), training (purple), and either NOR or NOL (yellow). NOR and NOL tests were spaced one week apart. C Representative objects used in behavioral testing were (from left to right): a brass gate valve, a combination lock, and a padlock. Scale bar = 3 cm. D Testing apparatus. A white opaque Plexiglas® open field box was used for testing. During habituation, no objects are placed in the open field box. During training two identical objects were placed in the box. In NOR testing, one of the identical objects was replaced with a novel one, whereas, in NOL one of the identical objects was moved to a novel location. During NOL a "clue tape" was placed on the wall of the open field box that served as a spatial orientation cue. All the phases were recorded with an overhead video camera