Gestational and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin affects social behaviors between developing rhesus monkeys (Macaca mulatta).
Pregnant rhesus monkeys (Macaca mulatta) were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at 30 and 300 ng/kg by subcutaneous injection at gestational day 20, followed by additional injections of TCDD (1.5 and 15 ng/kg, respectively) every 30 days till 90 days after parturition. The offspring delivered from these experimentally TCDD-exposed mothers were subjected to a series of behavioral tests after the weaning at 12-14 months old (MO): a finger maze learning task (12-15 MO), encounter tests between two monkeys (at 12-15 and 24-27 MO), and an eye-contact test (23-26 MO) to estimate learning ability, social interaction with a peer subject, and interest or hostility to a human observer, respectively. TCDD exposure had no significant effect on learning ability or interest/hostility to an observer. It did, however, significantly affect behavioral characteristics in the encounter tests. In the first encounter test, monkeys exposed to TCDD showed more visual exploration and mutual proximity but less stereotypy behavior compared to control monkeys. In the second encounter test, these differences seemed to disappear, suggesting that the behavioral effects of TCDD exposure in the encounter tests might disappear as the monkey develops. This study produced evidence of the behavioral toxicity of TCDD in social interactions using non-human primates.
Negishi
Takayuki
T
Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. taka-u@yayoi.club.ne.jp
Shimomura
Hiromi
H
Koyama
Takamasa
T
Kawasaki
Katsuyoshi
K
Ishii
Yoshiyuki
Y
Kyuwa
Shigeru
S
Yasuda
Mineo
M
Kuroda
Yoichiro
Y
Yoshikawa
Yasuhiro
Y
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004785:Environmental Pollutants / Q000493:pharmacokinetics / Q000633:toxicity*; D005260:Female; D005865:Gestational Age; D007774:Lactation; D008253:Macaca mulatta; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000493:pharmacokinetics / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000503:physiopathology*; D012919:Social Behavior
D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins