Skip to main content
. 2018 Dec 21;5(6):ENEURO.0455-18.2018. doi: 10.1523/ENEURO.0455-18.2018

Figure 2.

Figure 2.

Knock-down of Per1/Per2 mRNA in vmPFC prevents time-of-day-dependent (ZT16) superior conditioned fear extinction recall. Experimental timeline (upper panel): rats received bilateral microinfusion of AAV-Per1/Per2 shRNA+eGfp (KD) or control virus (SCR) in vmPFC and one week later were trained and tested in a 3-d auditory conditioned fear/extinction regimen at either ZT4 or ZT16. Freezing behavior (lower panel, mean ± SEM): there was no overall effect of time of day on day 1 acquisition, or 24-h conditioned fear recall (day 2, trial block 1), and no time of day by virus condition interaction for within session extinction (day 2, trial blocks 2–5). But rats given control virus had superior extinction recall at ZT16 compared to ZT4 (day 3, trial block 1). Knock-down of Per1/Per2 mRNA within the vmPFC prevented this superior extinction recall; *p < 0.05, ZT4 SCR versus ZT16 SCR (FLSD); #p < 0.05, ZT4 SCR versus ZT4 KD (FLSD), &p < 0.05, ZT16 SCR versus ZT16 KD (FLSD); †p < 0.05, ZT4 KD versus ZT16 KD (FLSD).