Early-Life Iron Deficiency Anemia Alters the Development and Long-Term Expression of Parvalbumin and Perineuronal Nets in the Rat Hippocampus

Abstract

Early-life iron deficiency anemia (IDA) alters the expression of genes involved in neuronal structural plasticity of the hippocampus, contributing to delayed maturation of electrophysiology, and learning and memory behavior in rats. Structural maturity in multiple cortical regions is characterized by the appearance of parvalbumin-positive (PV+) GABAergic interneurons and perineuronal nets (PNNs). Appearance of PV+ interneurons and PNNs serve as cellular markers for the beginning and end of a critical developmental period, respectively. ID rats had reduced PV mRNA expression and protein levels compared to IS controls. While there were no differences in the number of PV+ neurons at P30 or P65, the percentage of PV+ cells surrounded by PNNs was greater in ID rats as compared to IS controls. The alterations of these critical period biomarkers in the ID group are consistent with later maturation of the acutely ID hippocampus and lower plasticity in the adult formerly-ID hippocampus.