Impaired behaviour, learning and memory, in adult mice neonatally exposed to hexabromocyclododecane (HBCDD)

Brominated flame-retardants (BFRs) are a diverse group of global environmental pollutants. In the present study, we show that neonatal exposure to hexabromocyclododecane (HBCDD) can cause developmental behavioural defects that are similar to those recently reported for PBDEs and certain PCBs. Furthermore, HBCDD appears to be as potent as PBDEs in inducing developmental neurotoxic effects in mice. In this study, neonatal NMRI mouse pups were given either a single oral dose of 0.9mg HBCDD/kg body weight, 13.5mg HBCDD/kg body weight, or a 20% fat emulsion vehicle on postnatal day 10. At the age of 3 months, the mice were observed regarding spontaneous behaviour and concerning learning and memory capability. Mice exposed to 0.9mg HBCDD or to 13.5mg HBCDD/kg body weight showed a significantly altered spontaneous behaviour, manifested as a hyperactive condition and reduced habituation. Learning and memory, as observed in a Morris water maze, was also significantly affected in mice given the higher dose of HBCDD.