Environmental enrichment combined with voluntary exercise normalizes open field behavior three weeks after IFS.

<p>EE/VE started 1 week after the IFS procedure. (<b>A</b>). A percentage relative to non-shocked animals of the distance moved in the open field arena during a 5 minute test period is shown. (<b>B</b>) EE/VE normalizes the freezing behavior of IFS-exposed animals. *p<0.05 compared to non-shock control group. ^&p<0.05, compared to the IFS group under standard housing conditions. Values represent mean ± SEM. Group sizes: non-shock n = 12, shock n = 12.</p

Effects of environmental enrichment on locomotion in the openfield.

<p>(<b>A</b>) Environmental enrichment (EE) had no significant effect on locomotion in the open field one week after IFS. (<b>B</b>) Three weeks after the IFS EE normalizes open field behavior. Environmental enrichment started either 2 weeks before (EE-continues), immediately after (EE-after) or 1 week after (EE-delayed) the IFS procedure and continued until the end of the experiment. Values represent mean ± SEM. (*p<0.05, **p<0.01, ***p< 0.001). Group sizes: non-shock n = 12, shock n = 11</p

Monoamines levels in prefrontal cortex, hippocampus and amygdala following IFS and EE/VE.

<p>Levels of noradrenalin (<b>A</b>), 5-hydroxytryptamine (5-HT) (<b>B</b>) and 5-hydroxyindole-3-acetic acid (5-HIAA) (<b>C</b>) in the prefrontal cortex (PFC), hippocampus and the amygdala. The ratio of 5-HIAA and 5-HT (<b>D</b>) is indicative for the 5-HT turnover. # =  effect of housing p<0.05, ## =  effect of housing p<0.01, $ =  effect of shock p<0.05, *  =  post hoc p<0.05. Values represent mean ± SEM. Group sizes: n = 10–12.</p

Effects of IFS and environmental enrichment on cell proliferation/survival.

<p>Environmental enrichment started two weeks before the IFS procedure (EE-continues). (<b>A</b>) BrdU was injected immediately after the IFS procedure. In this way proliferation and survival during the three weeks post IFS was measured. (<b>B</b>) To quantify proliferation three weeks after the IFS procedure, BrdU was injected 21 days after the IFS and 24 hrs later the animals were sacrificied. BrdU incorporation was quantified by immunocytochemistry. Values represent mean ± SEM. Group sizes: non-shock n = 6, shock n = 6. * =  post-hoc analysis significanty different from its control group p<0.05, ***  = p<0.001. ### =  ANOVA significantly different effect of housing p<0.001.</p

Longitudinal effects of IFS on open field locomotion.

<p>Anxiolytic effects of the inescapable foot shock procedure are long lasting. The distance moved in the open field arena during a 5 minute test period is shown. (repeated measure ANOVA, p<0.001). Values represent mean ± SEM. Group sizes: non-shock n = 10, shock n = 10, ** =  post hoc analysis p<0.01.</p

Behavior in the light/dark box.

<p>The EE/VE induced normalization of the open field behavior of the IFS-exposed animals is not caused by loss of memory to the traumatic experience. Animals were placed in the lit compartment of the light/dark box (door open) that was used for the IFS procedure and (<b>A</b>) the latency to enter the dark compartment, (<b>B</b>) the total time spent in the lit compartment was quantified and (<b>C</b>) the number of passages from the lit into the dark compartment or vice versa during a five minute trial * =  Mann Whitney test significantly different from control group; p< 0.05, ** = p<0.01, *** = p<0.001, &  =  significantly different from IFS standard housed group. Values represent mean ± SEM. Group sizes: non-shock n = 12, shock n = 12.</p

Distance moved in open field per individulal animal.

<p>Distance moved in the open field arena one week and three weeks after the IFS procedure. Group sizes were: one week post shock, control n = 207, shock: n = 207, Three weeks post shock, control n = 127, shock: n = 127.</p