Fig. 7

Dramatic increases of apoptotic interneurons in the cerebral cortex of IN-PS cDKO mice. a-d Immunohistochemical analysis shows co-localization of active caspase-3- and GAD67-immunoreactivity (yellow arrowheads) in the neocortex and hippocampus of IN-PS cDKO mice. The few apoptotic cells (active caspas-3+) present in the neocortex and hippocampus of the control brain tend to be GAD67- (white arrowheads). Inserts show higher power views of the boxed areas. e Quantification of apoptotic interneurons (active caspase-3+/GAD67+) and apoptotic non- interneurons (active caspase-3+/GAD67-) in the neocortex and hippocampus of control and IN-PS cDKO mice at the age of 9 months. IN-PS cDKO mice show dramatic increases of apoptotic interneurons (active caspase-3+/GAD67+) in the neocortex (p < 0.0001, Student’s t-test) and hippocampus (p = 0.0002), compared to controls. There is no significant difference in the number of apoptotic non-interneurons (active caspase-3+/GAD67-) in the neocortex (p = 0.47, Student’s t-test) and hippocampus (p = 0.11) between IN-PS cDKO and control mice. f-i The few cells immunoreactive for both active caspase-3 and CaMKIIα are shown (cyan arrowheads) in the neocortex and hippocampus of control and IN-PS cDKO brains, whereas most apoptotic cells are non-excitatory neurons (active caspase-3+/CaMKIIα-) present in IN-PS cDKO brains (white arrowheads). Inserts show higher power views of the boxed areas. j Quantification of apoptotic excitatory neurons (active caspase-3+/CaMKIIα+) and apoptotic non-excitatory neurons (active caspase-3+/CaMKIIα-) in the neocortex and hippocampus of control and IN-PS cDKO mice at the age of 9 months. While there are dramatic increases of apoptotic non-excitatory neurons in the neocortex (p < 0.0001, Student’s t-test) and hippocampus (p < 0.0001) of IN-PS cDKO mice, compared to controls, there is no significant difference in the number of apoptotic excitatory neurons in the neocortex (p = 0.36, Student’s t-test) and hippocampus (p = 0.45) of IN-PS cDKO mice, compared to controls. Scale bar: 100 μm. All data represent mean ± SEM. ns = no significance, ***p < 0.001, ****p < 0.0001