Figure 4. GABAergic interneuron populations are altered in the hippocampal CA3-CA1 axis across investigated mouse strains. (A)Representative hippocampal sections with immunohistochemical staining for glutamate decarboxylase (GAD)67. (b) Summary data (B6J: N=8 mice; B6N: N=8 mice; 129: N=6 mice) showing a significant increased number of GAD67+ interneurons in both CA3 and CA1 subregions of 129 mouse strain. (c) Representative hippocampal sections with immunohistochemical staining for parvalbumin (PV). (d) Summary data (B6J: N=8 mice; B6N: N=8 mice; 129: N=6 mice) showing a significant decrease in the CA3 and CA1 PV+ interneuron number of B6N strain.(e) Representative hippocampal sections for immunohistochemical staining for somatostatin (SST). (f) Summary data (B6J: N=8 mice; B6N: N=8 mice; 129: N=7 mice) showing a significant increase in CA3 SST+ interneuron number of 129 mouse strain. Statistical comparison for (b), (d), (f): one-way-ANOVA followed by posthoc comparison using Fisher LSD Method. Post-hoc statistical differences are indicated via *p<0.05, **p<0.01 and ***p<0.001. Data are presented ± standard error of mean (SEM). Empty circles represent individual data points.