Stephanie Fretham (Bohmer)

Ph.D. 2010

Thesis Title:

The Impact of Iron Deficiency During Development on mTOR Signaling, Neuronal Structure, and Learning and Memory Behavior

Current Position:

Associate Professor, Department of Biology, Luther College

Undergraduate Institution and Major/Degree:

Luther College, BA Biology and Psychology, 2005

Major Advisor(s):

Michael Georgieff, M.D.

Research Description:

Iron deficiency during prenatal and early postnatal development is a common occurrence worldwide, and has lasting cognitive consequences.  My work focuses on identifying the cellular and genetic factors underlying the behavioral and cognitive phenotypes associated with perinatal iron deficiency. In particular, cellular signaling pathways which integrate energy availability and production and cellular growth and synaptic plasticity.  I utilize genetic mouse models in combination with qPCR, protein assays, IHC, and behavioral assessment to approach the question of how perinatal iron deficiency leads to neural and behavioral alterations which persist far beyond the period of deficiency.

Lab Rotations:

  • Scott Selleck
  • William Iacono
  • Michael Georgieff

Courses Taken Beyond the Core Courses:

  • Child Psychology: Cognitive Development (CPSY 8301)
  • Advanced Developmental Biology (GCD 8161)
  • Biochemical Aspects of Cell Growth and Death, (MICaB 8009)
  • Neurostatistics (NSC 8320)
  • Neurobiology in Disease (NSC 5667)
  • GRAD 8101: Teaching in Higher Education 

Committee Members:

  • Yasushi Nakagawa-Chair
  • Jonathan Gewirtz
  • Thomas Neufeld
  • Michael Georgieff-Advisor 

Conferences Attended and Presentations:

  • Society for Neuroscience annual meeting - Fall 2005, 2007
  • Society for Pediatric Research 2008 (Poster Symposium Presentation)

Selected Publications: 

  • Pisansky MT, Wickham RJ, Su J, Fretham S, Yuan LL, Sun M, Gewirtz JC, Georgieff MK. Iron deficiency with or without anemia impairs prepulse inhibition of the startle reflex. Hippocampus. 2013;23:952-962.
  • Bastian TW, Anderson JA, Fretham SJ, Prohaska JR, Georgieff MK, Anderson GW. Fetal and neonatal iron deficiency reduces thyroid hormone-responsive gene mRNA levels in the neonatal rat hippocampus and cerebral cortex. Endocrinology. 2012;153(11):5668-5680.
  • Fretham SJ, Carlson ES, Georgieff MK. Neuronal-specific iron deficiency dysregulates mammalian target of rapamycin signaling during hippocampal development in nonanemic genetic mouse models. J Nutr. 2013;143(3):260-266.
  • Fretham SJ, Carlson ES, Wobken J, Tran PV, Petryk A, Georgieff MK. Temporal manipulation of transferrin-receptor-1-dependent iron uptake identifies a sensitive period in mouse hippocampal neurodevelopment. Hippocampus. 2012;22(8):1691-1702.
  • Tran PV, Fretham SJ, Wobken J, Miller BS, Georgieff MK. Gestational-neonatal iron deficiency suppresses and iron treatment reactivates IGF signaling in developing rat hippocampus. Am J Physiol Endocrinol Metab. 2012;302(3):E316-24.
  • Fretham SJ, Carlson ES, Georgieff MK. The role of iron in learning and memory. Adv Nutr. 2011;2(2):112-21.
  • Carlson ES, Fretham SJ, Unger E, O'Connor M, Petryk A, Schallert T, Rao R, Tkac I, Georgieff MK. Hippocampus specific iron deficiency alters competition and cooperation between developing memory systems. J Neurodev Disord. 2010;2(3):133-143.
  • Tran PV, Fretham SJ, Carlson ES, Georgieff MK. Long-term reduction of hippocampal brain-derived neurotrophic factor activity after fetal-neonatal iron deficiency in adult rats. Pediatr Res. 2009;65(5):493-8.
  • Tran PV, Carlson ES, Fretham SJ, Georgieff MK. Early-life iron deficiency anemia alters neurotrophic factor expression and hippocampal neuron differentiation in male rats. J Nutr. 2008;138(12):2495-2501.

Awards and Honors:

  • Center for Neurobehavioral Development Fellowship, 2006-2007
  • Translational Research in Neurobiology of Disease Training Grant Recipient 2007-2008
  • National Research Service Award, NINDS. "The Effects of Early Iron Deficiency on mTOR Signaling" 2008-2011
  • Poppele Award, 2008

Home Town:

  • Estherville, IA
Stephanie Fretham