Figure 1.

Effects of the HDC gene disruption on nonreinforced object habituation (A) and episodic object memory based on temporal relationships (B-E). (Inserttop left) Scheme of the object exploration design. (A) Mean and sem total contacts for all identical objects on indicated days. (B,C) Mean and sem number of contacts with different objects on indicated days for HDC-KO and wild-type mice. (D,E) Mean and sem time spent in the four object quadrants on indicated days for HDC-KO and wild-type mice. P = HDC-KO versus WT, t-test for independent samples.