Neonatal exposure to trimethyltin disrupts spatial delayed alternation learning in preweanling rats.
Trimethyltin is an organotin compound that produces marked neurotoxicity in both adult and developing animals. The limbic system is a primary CNS target site for this toxicity, and a prominent behavioral effect of TMT is disruption of learning and memory. Impairment of cognitive development has also been suggested by studies showing that rats neonatally exposed to TMT cannot perform spatial working memory tasks during adulthood. However, the question of how early in ontogeny such deficits can be detected has not been addressed. The present study examined this question with a T-maze delayed alternation learning paradigm. Long-Evans rat pups, injected IP on Postnatal Day 10 (PND 10) with 6 mg/kg TMT and tested on PND 18, were unable to learn delayed alternation in the manner shown by vehicle control pups. However, TMT- and vehicle-treated groups were both able to learn a simple position discrimination. These findings indicate a selective impairment of spatial working memory by neonatal TMT exposure and show that this impairment can be demonstrated during the preweanling period in the rat.
Stanton
M E
ME
Neurotoxicology Division (MD-74B), United States Environmental Protection Agency, Research Triangle Park, NC 27711.
Jensen
K F
KF
Pickens
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CV
D000375:Aging; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002755:Choice Behavior / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000254:growth & development / Q000473:pathology*; D007858:Learning / Q000187:drug effects*; D009498:Neurotoxins / Q000633:toxicity*; D051381:Rats; D013028:Space Perception; D014298:Trimethyltin Compounds / Q000633:toxicity*
D009498:Neurotoxins; D014298:Trimethyltin Compounds; C046488:trimethyltin