title: Neonatal chlordecone exposure impairs early learning and retention of active avoidance in the rat.
abstract: The effect of neonatal exposure of rats to chlordecone on the acquisition and retention of active avoidance was investigated. Pups were trained and tested on one-way (preweaning) and/or two-way (post-weaning) active avoidance tasks. Offspring of Fischer-344 rats were administered 1 mg/pup of chlordecone (SC) dissolved in DMSO on postnatal day 4. Body weights were slightly, but significantly, depressed for chlordecone-exposed males (10-11%) and females (7-8%) during preweaning development. Post-weaning body weights were also slightly depressed by the chlordecone treatment (8% for the males, 7% for the females). For pups trained (day 18) on one-way (small to large compartment) active avoidance (OWA), chlordecone treatment increased the number of trials needed to attain the acquisition criterion; the effect was most pronounced in the males. A 72-hr retention test revealed a sex-dependent effect of chlordecone on response latency during the initial test trials. Acquisition of two-way avoidance (TWA) (days 28-30) was superior in female pups relative to males; chlordecone treatment significantly reduced this sex difference in pups which had prior or no prior OWA training. Perhaps most importantly, however, following prior OWA training, vehicle control pups demonstrated a directional bias to make an avoidance response from a small to a large compartment, whereas chlordecone-treated pups executed their avoidance responses in both directions at comparable rates. Similar evidence indicative of a selective retention deficit also characterized TWA performance when a "reversal" procedure was used. A final retention (extinction) session indicated that the chlordecone-treated pups made fewer responses than vehicle-treated controls during the test trials.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001362:Avoidance Learning / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D007631:Chlordecone / Q000633:toxicity*; D003345:Corticosterone / Q000097:blood; D005260:Female; D006128:Growth / Q000187:drug effects; D007306:Insecticides / Q000633:toxicity*; D007858:Learning / Q000187:drug effects*; D008297:Male; D008568:Memory / Q000187:drug effects*; D051381:Rats; D011916:Rats, Inbred F344; D012153:Retention, Psychology / Q000187:drug effects*; D012737:Sex Factors
chemical_list: D007306:Insecticides; D007631:Chlordecone; D003345:Corticosterone