private void _cell_PreviewClick(object sender, PreviewMouseEventArgs e)
{
    e.Brick.Text = "aaabbbccc"; e.PreviewControl.Refresh();
}

private void _cell_PreviewClick(object sender, PreviewMouseEventArgs e)
{
    e.Brick.Text = "aaabbbcc";
    otherCell1.Text = "rrrttcwwww"
    e.PreviewControl.Refresh();
}