Lead exposure and (n-3) fatty acid deficiency during rat neonatal development affect subsequent spatial task performance and olfactory discrimination.
Docosahexaenoic acid [22:6(n-3), DHA] is important for optimal infant central nervous system development, and lead (Pb) exposure during development can produce neurological deficits. Long-Evans strain rats were fed either an (n-3) deficient [(n-3) Def] diet to produce brain DHA deficiency, or an adequate [(n-3) Adq] diet through 2 generations. At the birth of the 2nd generation, the dams were subdivided into 4 groups and supplied drinking water containing either 5.27 mmol/L (Pb) or sodium (Na) acetate until weaning. Rats were killed at 3 wk (weaning) and 11 wk (maturity) for brain Pb and fatty acid analysis. Spatial task and olfactory-cued behavioral assessments were initiated at 9 wk. Rats in the (n-3) Def group had a 79% lower concentration of brain DHA compared with the (n-3) Adq group with no effect of Pb exposure. At weaning, Pb concentrations were 7.17 +/- 0.47 nmol Pb/g of brain (wet weight) in the (n-3) Adq-Pb group and 6.49 +/- 0.63 nmol Pb/g of brain (wet weight) in the (n-3) Def-Pb group. At maturity, the brains contained 1.30 +/- 0.22 and 1.07 +/- 0.12 nmol Pb/g (wet weight), respectively. In behavioral testing, significant effects of both Pb and DHA deficiency were observed in the Morris water maze probe trial and in 2-odor olfactory discrimination acquisition and olfactory-based reversal learning tasks. Both lactational Pb exposure and (n-3) fatty acid deficiency led to behavioral deficits with additive effects observed only in the acquisition of 2-odor discriminations.
Lim
Sun-Young
SY
Division of Ocean Science, Korea Maritime University, Busan, Korea.
Doherty
John D
JD
McBride
Kathleen
K
Miller-Ihli
Nancy J
NJ
Carmona
Gilberto N
GN
Stark
Ken D
KD
Salem
Norman
N
D000375:Aging / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D004192:Discrimination, Psychological / Q000187:drug effects; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D007854:Lead / Q000494:pharmacology*; D018782:Maze Learning / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D009812:Odorants; D051381:Rats; D020318:Rats, Long-Evans; D012903:Smell / Q000187:drug effects / Q000502:physiology*; D013028:Space Perception / Q000187:drug effects / Q000502:physiology*
D004281:Docosahexaenoic Acids; D007854:Lead