Typical results of two-photon imaging for juvenile NR and GR mice.

<p>(A) Image of Ca²⁺ signals in a slice of the VI of an NR mouse. Fluorescence signals from OGB-1 (green) and SR101 (orange) identify neurons and astrocytes, respectively. Dark spots and strips indicate blood vessels. The scale bar indicates 100 µm. (B) Traces of Ca²⁺ responses of four neurons to stimulus orientations of grating stimuli, where stimulus orientations are indicated by the inclinations of the black bars placed below. These four neurons were located at positions indicated by the numbered arrows in (A). Gray columns represent 5 s stimulation periods. Vertical and horizontal bars respectively indicate 5% () and 5 s. (C) Color-coded images of vigorously responsive neurons in single slices of an NR mouse (left) and a mouse GR from P23 to P31 (right), which were reconstructed from two-photon Ca²⁺ imaging conducted at P42 and P31, respectively. The left image was reconstructed from the Ca²⁺ signals in the slice shown in (A). The color of the dots indicates the preferred orientation, whereas gray dots indicate responsive but unoriented neurons. The color code is shown below the left image. (D) Group-averaged orientation distributions for NR (n = 3) and GR (n = 3) mice. Error bars indicate SE. The scale bar indicates 100 µm.