Perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin alters activity-dependent expression of BDNF mRNA in the neocortex and male rat sexual behavior in adulthood.
Dioxin and its related compounds are suspected to cause neurological and nueroendocrinological disruption in human and laboratory animal offspring upon in utero and lactational exposure during growth and development. We tested the hypothesis by utilizing Long-Evans Hooded rats that perinatal exposure to dioxins affects the neocortical function and expression of sexual behavior in adulthood. In the sexual behavior test, perinatal exposure to TCDD significantly reduced the number of mounts and intromissions. The mRNA semi-quantification in in situ hybridization showed that the mating stimulus in control males induced c-fos mRNA expression in the preoptic area (POA) and the brain derived neurotrophic factor (BDNF) mRNA upregulation in the frontal cortex. In contrast, perinatal exposure to TCDD lowered the upregulation of BDNF mRNA in the frontal cortex but not that of c-fos mRNA in the POA. The volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) was not affected. The results suggest that perinatal TCDD affects the neocortical function independently from the brain sexual differentiation and alters the expression of sexual behavior.
Kakeyama
Masaki
M
Environmental Health Sciences Division, National Institute for Environmental Studies, Onogawa 16-2, Tsukuba 305-8506, Japan. kake@nies.go.jp
Sone
Hideko
H
Miyabara
Yuichi
Y
Tohyama
Chiharu
C
D000818:Animals; D000831:Animals, Newborn; D001923:Brain Chemistry / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000096:biosynthesis*; D008401:Gas Chromatography-Mass Spectrometry; D015870:Gene Expression / Q000187:drug effects; D016762:Genes, fos / Q000187:drug effects; D017403:In Situ Hybridization; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D019579:Neocortex / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D011301:Preoptic Area / Q000187:drug effects / Q000254:growth & development; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D020318:Rats, Long-Evans; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D013737:Testis / Q000187:drug effects / Q000254:growth & development; D015854:Up-Regulation / Q000187:drug effects; D015430:Weight Gain / Q000187:drug effects
D019208:Brain-Derived Neurotrophic Factor; D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger