Effect of maternal separation and chronic stress on hippocampal-dependent memory in young adult rats: evidence for the match-mismatch hypothesis

Figures & data

Figure 1. Effect of early maternal separation and variable chronic stress on the total volume (in mm³, mean ± SE) of the dorsal hippocampus. The number of animals for each treatment is included inside each bar.

Figure 2. Effect of early maternal separation and variable chronic stress on the volume (in mm³, mean ± SE) of the CA1 (A), CA2/CA3 (B) and DG (C) areas of the dorsal hippocampus and their respective strata (D–F). The number of animals for each treatment is included inside each bar.

Figure 3. Effect of early maternal separation and variable chronic stress on freezing behavior recorded on the first day of the test, during the conditioning and post-conditioning stages (A) and during memory retrieval 24 h after conditioning (B). Values represent the percentage time of freezing (mean ± SE) for animals tested in the same context. The number of cases for each treatment is included inside each bar. (*) Means significant difference between groups (p < 0.05). Post hoc analysis showed significant difference between NMS-CVS and controls (NMS-NCVS) and MS-CVS during post-conditioning (A) and between NMS-CVS and controls (NMS-NCVS) during memory retrieval (B).

Table 1. Results of the two-way ANOVA analysis from dorsal hippocampal, its areas and strata volumes.

	Rearing condition		Stress		Interaction
	(df, 1,18)		(df, 1,18)		(df, 1,18)
Volumes	F	p	F	p	F	p
Dorsal hippocampus	0.02	0.877	0.95	0.342	2.12	0.163
CA1 area	0.04	0.845	1.70	0.209	1.44	0.246
Pyramidal stratum	0.48	0.498	0.52	0.479	0.60	0.449
Apical stratum	0.01	0.913	3.14	0.093	3.06	0.097
Basal stratum	0.08	0.782	0.19	0.669	0.21	0.653
CA2/3 area	0.01	0.942	0.95	0.343	1.84	0.191
Pyramidal stratum	0.55	0.468	0.59	0.452	0.80	0.382
Apical stratum	0.57	0.462	1.33	0.263	3.40	0.082
Basal stratum	0.04	0.837	0.83	0.373	1.78	0.199
Dentate Gyrus	0.05	0.826	0.09	0.767	2.29	0.148
Granular layer	0.22	0.646	0.33	0.576	1.16	0.297
Polymorphic layer	0.0006	0.980	0.97	0.337	2.30	0.146
Molecular layer	0.22	0.642	0.61	0.444	1.91	0.184

F and p values corresponding to main effects (rearing condition and stress) and their interaction on dorsal hippocampal, its areas and strata volumes from all experimental groups. df, degrees of freedom.