Figure 3.

Effects of Src kinase blocker on E2-induced spine increase and change in morphology. (A) Spines were analyzed along the secondary dendrites of pyramidal neurons in the stratum radiatum of CA1 neurons as in Figure 1. Dendrite after E2-treatment for 2 h (E2) and dendrite after E2 plus PP2 treatment for 2 h (PP2+E2). (Spiso) shows the image of dendrite and spines analyzed with Spiso-3D software. Maximal intensity projections onto XY plane is shown. Traced dendrite is shown in red color and spines are indicated in yellow color. (Model) shows 3 dimensional model illustration of (Spiso) image. Bar, 5 μm. (B) Effect of treatments by E2 and PP2 on the total spine density. Vertical axis is the average number of spines per 1 μm of dendrite. A 2 h treatment in ACSF without drugs (Control), with 1 nM E2 (E2), and with 1 nM E2 and 10 μM PP2 (PP2 + E2). (C) Histogram of spine head diameters. A 2 h treatment in ACSF without drugs (Control, dashed line), with E2 (black line), with E2 + PP2 (red line). (D) Density of three subtypes of spines. From left to right, small-head spines (small), middle-head spines (middle), and large-head spines (large) type. In each group, control (open column), E2 (black column), and PP2+E2 (red column). Results are represented as mean ± SEM. Statistical significance was defined as *p < 0.05, **p < 0.01 vs. E2 sample. For E2 and PP2+E2 treatments, we investigated 50 dendrites with 2300–2700 spines from 3 rats, 12 slices, and 30 neurons. For control, we used 80 dendrites with ~4,000 spines from 6 rats, 24 slices, and 50 neurons.