Short-term novel object recognition memory. (a) Drug administration protocol used during the novel object recognition (NOR) task (Hab, Habituation session; Fam, Familiarization session; Test session). (b) Saline (Sal)-treated TgCHRNA5/A3/B4 (Tg) mice presented a significant impairment in recognition memory, as compared to wild type (WT) littermates, as shown by reduced discrimination index which was expressed as [(time exploring the novel object - time exploring the familiar object)/total time of exploration*100]. Chronic administration of nicotine (Nic, 3.25 mg/kg/d) for 5 d rescued the impaired recognition memory in Tg mice, but had no effect in WT (n = 10-12 animals/group from ≥ 3 experiments). *p ≤ 0.05, **p ≤ 0.01.