Tokyo stocks opened lower Thursday, weighed down by selling of technology shares after their U.S. counterparts dropped overnight. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average fell 315.73 points, or 0.81 percent, from Wednesday to 38,892.30. The broader Topix index was down 13.10 points, or 0.49 percent, at 2,661.85. On the top-tier Prime Market, decliners were led by iron and steel, nonferrous metal, and electric power and gas shares. At 9 a.m., the U.S. dollar fetched 150.66-67 yen compared with 150.64-74 yen in New York and 150.74-75 yen in Tokyo at 5 p.m. Wednesday…