Figure 3.

Latencies to reach the hidden platform during Morris water maze spatial learning and memory in WT and Ube3a mice given four daily training trials spaced at 1 h intervals, and treated with either vehicle or the TrkB receptor agonist 7,8-dihydroxyflavanone (7,8-DHF, 5 mg/kg i.p.). (A) WT in both the vehicle and 7,8-DHF groups successfully reached the acquisition criterion of under 15 sec to reach the hidden platform location. No significant difference was detected in the time course for acquisition across training days in WT mice treated with vehicle and 7,8-DHF. (B) Ube3a in both the vehicle and 7,8-DHF groups did not successfully reach the acquisition criterion of under 15 sec to reach the hidden platform location, although acquisition latencies at day 10 were generally lower after spaced training trials than latencies at day 10 after the massed training trials shown in Figure 2. This observation extends previous findings of better learning with spaced versus massed training in 2- to 3-mo-old Ube3a mice (Lauterborn et al. 2019). No significant difference was detected in the time course across training days for acquisition by Ube3a mice treated with vehicle versus 7,8-DHF.