title: Maternal iron deficiency worsens the associative learning deficits and hippocampal and cerebellar losses in a rat model of fetal alcohol spectrum disorders.
abstract: BACKGROUND
  Gestational alcohol exposure causes lifelong physical and neurocognitive deficits collectively referred to as fetal alcohol spectrum disorders (FASDs). Micronutrient deficiencies are common in pregnancies of alcohol-abusing women. Here we show the most common micronutrient deficiency of pregnancy-iron deficiency without anemia-significantly worsens neurocognitive outcomes following perinatal alcohol exposure.
  
  
  METHODS
  Pregnant rats were fed iron-deficient (ID) or iron-sufficient diets from gestational day 13 to postnatal day (P) 7. Pups received alcohol (0, 3.5, 5.0 g/kg) from P 4 to P 9, targeting the brain growth spurt. At P 32, learning was assessed using delay or trace eyeblink classical conditioning (ECC). Cerebellar interpositus nucleus (IPN) and hippocampal CA1 cellularity was quantified using unbiased stereology.
  
  
  RESULTS
  Global analysis of variance revealed that ID and alcohol separately and significantly reduced ECC learning with respect to amplitude (ps ≤ 0.001) and conditioned response [CR] percentage (ps ≤ 0.001). Iron and alcohol interacted to reduce CR percentage in the trace ECC task (p = 0.013). Both ID and alcohol significantly reduced IPN (ps < 0.001) and CA1 cellularity (ps < 0.005). CR amplitude correlated with IPN cellularity (delay: r = 0.871, trace: r = 0.703, ps < 0.001) and CA1 cellularity (delay: r = 0.792, trace: r = 0.846, ps < 0.001) across both tasks. The learning impairments persisted even though the offsprings' iron status had normalized.
  
  
  CONCLUSIONS
  Supporting our previous work, gestational ID exacerbates the associative learning deficits in this rat model of FASD. This is strongly associated with cellular reductions within the ECC neurocircuitry. Significant learning impairments in FASD could be the consequence, in part, of pregnancies in which the mother was also iron inadequate.
authors.affiliation: Departments of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Shane M
authors.initials: SM
authors.lastname: Huebner
authors.affiliation: Department of Psychology, Multidisciplinary Studies Program in Neuroscience, East Carolina University, Greenville, North Carolina.
authors.forename: Tuan D
authors.initials: TD
authors.lastname: Tran
authors.affiliation: Departments of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Echoleah S
authors.initials: ES
authors.lastname: Rufer
authors.affiliation: Computing and Biometry, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Crump
authors.affiliation: Departments of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Smith
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000150:complications / Q000473:pathology*; D000818:Animals; D000831:Animals, Newborn; D001245:Association Learning / Q000187:drug effects / Q000502:physiology*; D002531:Cerebellum / Q000187:drug effects / Q000473:pathology*; D003215:Conditioning, Eyelid / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D000431:Ethanol / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders / Q000209:etiology / Q000473:pathology*; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology*; D011247:Pregnancy; D051381:Rats; D020318:Rats, Long-Evans
chemical_list: D000431:Ethanol
keywords: Cerebellum; Eyeblink Conditioning; Fetal Alcohol Spectrum Disorders; Hippocampus; Iron Deficiency; Stereology