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:

Assistant Professor, 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, M.T., Wickham, R.J, Su, J., Fretham, S.J.B, Yuan, L., Sun, M., Gewirtz, J.C., Georgieff, M.K. (2013). Iron Deficiency with or without Anemia Impairs Prepulse Inhibition of the Startle Reflex. Hippocampus. 23(10); 952-962.
  • Fretham, S.J.B., Carlson, E.S., Georgieff, M.K. (2013). Neuronal-Specific Iron Deficiency Dysregulates Mammalian Target of Rapamycin Signaling During Hippocampal Development in the Mouse. Journal of Nutrition. 143: 260-266.
  • Bastian, T.W., Anderson, J.A., Fretham, S.J.B., Prohaska, J.R., Georgieff, M.K., Anderson, G.W. (2012). Fetal and neonatal iron deficiency reduces thyroid hormone-responsive gene mRNA levels in the neonatal rat hippocampus and cerebral cortex. Endocrinology. 153(11):5668-5680.
  • Fretham S.J.B., 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 Aug;22(8):1691-702.
  • Fretham, S.J.B., Carlson E.S., Petryk A., Georgieff, M.K. (2012). Timing of Prevention of Long-term Behavioral Deficits in an Inducible Mouse Model of Hippocampal Fetal-Neonatal Iron Deficiency. Hippocampus. Published online February 27, 2012.
  • Tran, P.V, Fretham, S.J.B., Wobken, J., Miller, B.S., Georgieff, M.K. (2012). Gestational-Neonatal Iron Deficiency Suppresses and Iron Treatment Re-Activates IGF Signaling in Developing Rat Hippocampus. Am J Physiol Endocrinol Metab. 302:E316-E324.
  • Fretham, S.J.B., Carlson, E.S., Georgieff, M.K. (2011). The Role of Iron in Learning and Memory. Advances in Nutrition. 2:112-121.
  • Carlson, E.S., Fretham, S.J.B., Unger, E., O’Connor, M.B., Petryk, A., Schallert, T., Rao, R., Tkac, I., Georgieff, M.K. (2010). Hippocampus Specific Iron Deficiency Alters Competition and Cooperation Between Developing Memory Systems. J Neurodev Disord. 2(3):133-143.
  • Tran, P., Fretham, S.J.B., Carlson, E.S., Georgieff, M.K. (2009). Long-Term Reduction of Hippocampal BDNF Activity Following Fetal-Neonatal Iron Deficiency in Adult Rats. Pediatric Research, 65(5):493-498.
  • Tran, P., Carlson, E.S., Fretham, S.J.B., Georgieff, M.K. (2008). Early-life Iron Deficiency Anemia Alters Neurotrophic Factor Expression and Hippocampal Neuron Differentiation in Male Rats. Journal of Nutrition, 138(12):2495-501.

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