1. Department of Industrial Pharmacy, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
2. Department of Pharmacology, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA
3. Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA
4. Department of Biophysical Chemistry, Faculty of Pharmaceutical Sciences, Nagasaki International University, Sasebo, Nagasaki 859-3298, Japan