Behavior progression during the 20 minutes of social interaction (pre-FCT) represented in blocks of interval of 5 minutes

The graphs represent rates between opponents of frequency of (A) attacks, (B) knocking-down, and (C) offensive behavior. *  <p><b>Copyright information:</b></p><p>Taken from "Stress Amplifies Memory for Social Hierarchy"</p><p></p><p>Frontiers in Neuroscience 2007;1(1):175-184.</p><p>Published online Jan 2007</p><p>PMCID:PMC2518054.</p><p></p

Group-housed rats maintained their previous hierarchy status after being re-housed together once the social memory experiments were finished (day 8)

In the left panel the graph represents the water consumption ratio average between group-cage rats during the WCT performed the week before the experiment started (pre-experiment) and when they were re-housed together after the WCT on day 8 (A). Rats with the highest ratio in time dedicated to water consumption during the WCT pre-experiment were identified as alpha (blank bars), those with the lowest ratio as omega (bars with horizontal lines), and the rats in between both types as beta (bars with slant lines). **  <p><b>Copyright information:</b></p><p>Taken from "Stress Amplifies Memory for Social Hierarchy"</p><p></p><p>Frontiers in Neuroscience 2007;1(1):175-184.</p><p>Published online Jan 2007</p><p>PMCID:PMC2518054.</p><p></p

Open field test.

<p>(A) Exploration of the central zone was measured as an index of anxiety-like behavior. LIP- and KA-treated rats from both strains showed increased exploration of the central zone. (B) Total distance traveled. The results are presented as the mean ± SEM. * P<0.05, ** P<0.01, and *** P<0.0001 vs. their respective control groups. Abbreviations: W: Wistar; SD: Sprague-Dawley; LIP: lithium-pilocarpine; KA: kainic acid.</p

Plasma corticosterone levels assessed before (pre-behavioral phase) and after (post-behavioral phase) the behavioral tests.

<p>The results are presented as the mean ± SEM. ** P<0.01 vs. the corresponding pre-behavioral data from the same group. For this analysis, strains were pooled. Abbreviations: LIP: lithium-pilocarpine; KA: kainic acid.</p

Anhedonia test.

<p>(A) Saccharin consumption and (B) saccharin preference was assessed in all groups simultaneously. The data for saccharin consumption per 100 g body weight (A) showed increased saccharin intake in LIP-treated rats compared with controls and KA-treated animals, regardless of the strain. The data for saccharin preference (B) indicated no differences between groups. The results are presented as the mean ± SEM. # P<0.05; ** P<0.01. Abbreviations: W: Wistar; SD: Sprague-Dawley; LIP: lithium-pilocarpine; KA: kainic acid.</p

Social interaction test.

<p>(A) The juvenile exploration ratio represents time spent exploring the juvenile rat over the total time spent exploring the juvenile rat and the object, evaluated during the 10 min session of the test. Both SE models regardless of the strain, but especially LIP-treated animals, showed decreased preference for exploration of the juvenile conspecific. (B) Total distance traveled in the social interaction test. The results are presented as the mean ± SEM. * P<0.05; *** P<.0001; +++ P<.0001. Abbreviations: W: Wistar; SD: Sprague-Dawley; LIP: lithium-pilocarpine; KA: kainic acid.</p

Effects of nectin-1 inhibition in the ventral hippocampus on anxiety-like behavior (A) and locomotor activity (B).

<p>Inhibition of nectin-1 by infusion of R165 into the ventral hippocampus did not affect time spent in the center, the rim area of the open field as measured 7 d later (A). In addition, locomotor activity in the open field was also not affected by R165 infusion 7 d before (B). Error bars represent standard error of the mean (n = 14 for ACSF-treated animals, n = 19 for R165-treated animals).</p

Effect of nectin-1 inhibition on fear memory consolidation.

<p>Prior to treatment, there was no difference in the freezing response during CFC. Inhibition of nectin-1 by R165 infusion in the ventral hippocampus immediately after CFC reduced freezing as measured at 2 and 7 d after contextual fear training (A). This effect was not seen for the dorsal hippocampus (B). Error bars represent standard error of the mean (n = 7 animals/group) (n.s., no significant difference; *, p<0.05: treatment effect R165 vs. control indicated by two-way ANOVA).</p

Effect of nectin-1 on fear memory consolidation tested 7 d after training.

<p>Prior to treatment, there was no difference in the freezing response during CFC. Inhibition of nectin-1 by R165 infusion in the ventral hippocampus immediately after CFC reduced freezing when tested at 7d later (n = 7 animals/group) (n.s., no significant difference; *, p<0.05 vs. control group, two-tailed Student t-test).</p

Effect of context, shock and contextual fear conditioning on nectin-1 (A, B) and nectin-3 (C, D) protein expression in synaptic fractions of ventral and dorsal hippocampi.

<p>The increase of nectin-1 at 2 h after CFC was not seen after context- or shock exposure alone and was restricted to ventral hippocampus (A). Nectin-1 levels in the dorsal hippocampus were not affected 2 h after shock, context or CFC (B). Nectin-3 levels in both ventral- (C) and dorsal hippocampus (D) were unaffected 2 h after context, shock or CFC. Error bars represent standard error of the mean (n = 7–10 animals/group) (*, p<0.05; ** p<0.01 vs. control group indicated by Bonferroni post hoc test).</p