Maternal isobutyl-paraben exposure alters anxiety and passive avoidance test performance in adult male rats

• Published in: Neuroscience research Vol. 65; no. 2; pp. 136 - 140
• Main Authors: Kawaguchi, Maiko, Irie, Kaoru, Morohoshi, Kaori, Watanabe, Gen, Taya, Kazuyoshi, Morita, Masatoshi, Kondo, Yasuhiko, Imai, Hideki, Himi, Toshiyuki
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.10.2009
• Subjects: Aging - physiology; Animals; Anxiety; Anxiety Disorders - chemically induced; Anxiety Disorders - physiopathology; Avoidance Learning - drug effects; Avoidance Learning - physiology; Brain - drug effects; Brain - growth & development; Brain - physiopathology; Cholesterol - pharmacology; Development; Disease Models, Animal; Elevated plus maze; Environmental Exposure - adverse effects; Estradiol - pharmacology; Estrogen; Female; Isobutyl-paraben; Learning Disorders - chemically induced; Learning Disorders - physiopathology; Male; Maze Learning - drug effects; Maze Learning - physiology; Organogenesis - drug effects; Organogenesis - physiology; Ovariectomy; Parabens - toxicity; Passive avoidance; Pregnancy; Prenatal Exposure Delayed Effects - physiopathology; Rat; Rats; Rats, Sprague-Dawley; Sex Characteristics; Rat; Isobutyl-paraben; Elevated plus maze; Passive avoidance; Estrogen; Development; Anxiety
• ISSN: 0168-0102; 1872-8111
• DOI: 10.1016/j.neures.2009.06.011

Isobutyl-paraben (IBP), one of the most widely used preservatives, exhibits estrogenic activity. In this study, we analyzed the effects of maternal IBP treatment on the emotional behavior and learning performance in mature offspring. Pregnant female Sprague–Dawley rats were treated with IBP via a subcutaneous Silastic capsule. Consequently, the offspring were exposed to IBP during gestation through the placentae, and before weaning through the milk. Male and female offspring were tested for emotional behavior in an open field and in an elevated plus maze at five and six weeks old, respectively. IBP-exposed male (but not female) rats spent less time in the open arms of the elevated plus maze. At 11 weeks old, all females were gonadectomized and treated chronically with 17β-estradiol or cholesterol by Silastic capsules; all males were kept intact. They were tested for learning performance in a passive avoidance test and a Morris water maze. IBP exposure impaired the performance of males in the passive avoidance test. These findings suggest that male rats are more affected by early exposure to IBP than female rats. IBP affects their adult behavior including anxiety and learning abilities.