Perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin suppresses contextual fear conditioning-accompanied activation of cyclic AMP response element-binding protein in the hippocampal CA1 region of male rats.
We investigated the effect of in utero and lactational exposures to dioxin on adult offspring with contextual fear conditioning, a sex- and hippocampus-dependent learning paradigm; and we measured the conditioning-accompanied activation of cyclic AMP response element-binding protein (CREB) in the hippocampal CA1 region. Pregnant rats were treated with a low dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gestation day 15. TCDD treatment decreased freezing time in conditioning tests of adult male offspring but not of female offspring. A similar, male-specific decrease was observed in the percentage of phosphorylated CREB-immunoreactive neurons in the CA1 region following conditioning in TCDD-treated rats. These results suggest that perinatal TCDD exposure impairs hippocampus-dependent learning in male offspring by suppressing CREB activation.
Mitsui
Tetsuo
T
Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, The University of Yamanashi, Yamanashi 409-3898, Japan.
Sugiyama
Nobuhiro
N
Maeda
Shuichiro
S
Tohyama
Chiharu
C
Arita
Jun
J
D000818:Animals; D003213:Conditioning, Psychological; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004785:Environmental Pollutants / Q000633:toxicity*; D005239:Fear; D005260:Female; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D018811:Maternal Exposure; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017208:Rats, Wistar; D012737:Sex Factors
D017362:Cyclic AMP Response Element-Binding Protein; D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins