<p>(<b>A</b>) TLR4<sup>−/−</sup> (n = 19) and TLR4<sup>+/+</sup> (n = 24) mice were tested in probe trials at 24, 48, 72 and 96 hours following training for retention of spatial reference memory. Tests were done after all experimental groups exhibited loss of memory of the platform location. Mean distance from the platform was measured and used to indicate efficiency in locating the hidden platform. TLR4<sup>−/−</sup> mice showed shorter mean distance from the platform at 24 and 48 hours after training compared with TLR4<sup>+/+</sup> mice, indicating a more accurate swim toward the platform quadrant (<b>B</b>) Mice (C57BL/6) were implanted with an osmotic pump containing either aCSF (n = 10) or a TLR4 antagonist (n = 10). The pump was connected via tubing to a cannula, which was positioned to the lateral ventricle. Following training in the MWM task, mice were tested in probe trials at 24 and 48 hours following training for retention of spatial reference memory. Both experimental groups exhibited similar performance during probe trials, as measured by mean distance from the platform.</p
