Tokyo stocks fell Wednesday morning, with export-related issues hit by a stronger yen in cautious trading as investors awaited the outcome of the U.S. presidential debate. The 225-issue Nikkei Stock Average shed 291.83 points, or 0.81 percent, from Tuesday to 35,867.33. The broader Topix index was down 23.74 points, or 0.92 percent, at 2,552.80. The U.S. dollar briefly sank to the mid-141 yen zone, its lowest level since January, as the yen was bought after a speech by a Bank of Japan policymaker that was seen by the market as displaying a positive stance toward further raising interest rates,…