Behavioral changes in aging but not young mice after neonatal exposure to the polybrominated flame retardant decaBDE.
BACKGROUND
After several decades of commercial use, the flame-retardant chemicals polybrominated diphenyl ethers (PBDEs) and their metabolites are pervasive environmental contaminants and are detected in the human body. Decabrominated diphenyl ether (decaBDE) is currently the only PBDE in production in the United States.


OBJECTIVE
Little is known about the health effects of decaBDE. In the present study we examined the effects of neonatal decaBDE exposure on behavior in mice at two ages.


METHODS
Neonatal male and female C57BL6/J mice were exposed to a daily oral dose of 0, 6, or 20 mg/kg decaBDE from postnatal days 2 through 15. Two age groups were examined: a cohort that began training during young adulthood and an aging cohort of littermates that began training at 16 months of age. Both cohorts were tested on a series of operant procedures that included a fixed-ratio 1 schedule of reinforcement, a fixed-interval (FI) 2-min schedule, and a light-dark visual discrimination.


RESULTS
We observed minimal effects on the light-dark discrimination in the young cohort, with no effects on the other tasks. The performance of the aging cohort was significantly affected by decaBDE. On the FI schedule, decaBDE exposure increased the overall response rate. On the light-dark discrimination, older treated mice learned the task more slowly, made fewer errors on the first-response choice of a trial but more perseverative errors after an initial error, and had lower latencies to respond compared with controls. Effects were observed in both dose groups and sexes on various measures.


CONCLUSIONS
These findings suggest that neonatal decaBDE exposure produces effects on behavioral tasks in older but not younger animals. The behavioral mechanisms responsible for the pattern of observed effects may include increased impulsivity, although further research is required.
Rice
Deborah C
DC
Environmental and Occupational Health Program, Maine Center for Disease Control and Prevention, Augusta, Maine, USA.
Thompson
W Douglas
WD
Reeve
Elizabeth A
EA
Onos
Kristen D
KD
Assadollahzadeh
Mina
M
Markowski
Vincent P
VP
D000375:Aging / Q000523:psychology*; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects*; D003216:Conditioning, Operant / Q000187:drug effects; D004193:Discrimination Learning / Q000187:drug effects; D005260:Female; D005411:Flame Retardants / Q000633:toxicity*; D055768:Halogenated Diphenyl Ethers / Q000633:toxicity*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012055:Reinforcement Schedule; D012727:Sex Characteristics
D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; C010902:decabromobiphenyl ether