Fig. 2

Overexpression of KCC2 increases spine density. a Representative CA1 pyramidal neuron dendrites in Golgi-stained hippocampal slices from WT and KCC2-overexpressing mice. Scale bars, 5 μm. b The density of spines in CA1 hippocampal pyramidal neurons was significantly increased in KCC2-overexpressing mice. Spine density in the KCC2 mice was 1.06 ± 0.10 spines/μm (15 dendrites from 5 mice), while the spine density in the control group was 0.69 ± 0.07 (12 dendrites from 4 mice), corresponding to a 54% increase (**p < 0.01, unpaired t test). c Representative images of single dendrites in WT and KCC2-overexpressing mice using in vivo two-photon imaging of dendrites and spines in apical dendrites of layer V pyramidal neurons of the motor cortex. Scale bars, 5 μm. d In KCC2-overexpressing mice (34 dendrites, 16 animals), there was a significant increase in spine density compared with WT mice (18 dendrites, 11 animals ***p < 0.001, unpaired t test). Graphs show individual data with mean ± SEM)