[1] Univ Murcia, Fac Biol, Dept Physiol, E-30100 Murcia, Spain
[2] Univ Murcia, Fac Med, Dept Human Anat & Psychobiol, Murcia, Spain
[3] Univ Valencia, Fac Med, Dept Philosophy, Valencia, Spain
[4] Univ Texas Hlth Sci Ctr San Antonio, Dept Cellular & Struct Biol, San Antonio, TX 78229 USA
[5] Univ Extremadura, Sch Nursing, Dept Physiol, Caceres, Spain