SHORT COMMUNICATION Experimentally-induced maternal hypothyroidism alters crucial enzyme activities in the frontal cortex and hippocampus of the offspring rat Christos Koromilas & Stylianos Tsakiris & Konstantinos Kalafatakis & Apostolos Zarros & Vasileios Stolakis & Despoina Kimpizi & Alexios Bimpis & Anastasia Tsagianni & Charis Liapi Received: 27 April 2014 /Accepted: 23 June 2014 /Published online: 29 June 2014 # Springer Science+Business Media New York 2014 Abstract Thyroid hormone insufficiency during neurodevelopment can result into significant structural and functional changes within the developing central nervous system (CNS), and is associated with the establishment of serious cognitive impairment and neuropsychiatric symptom- atology. The aim of the present study was to shed more light on the effects of gestational and/or lactational maternal expo- sure to propylthiouracil (PTU)-induced hypothyroidism as a multilevel experimental approach to the study of hypothyroidism-induced changes on crucial brain enzyme activities of 21-day-old Wistar rat offspring in a brain region-specific manner. This experimental approach has been recently developed and characterized by the authors based on neurochemical analyses performed on newborn and 21-day- old rat offspring whole brain homogenates; as a continuum to this effort, the current study focused on two CNS regions of major significance for cognitive development: the frontal cortex and the hippocampus. Maternal exposure to PTU in the drinking water during gestation and/or lactation resulted into changes in the activities of acetylcholinesterase and two important adenosinetriphosphatases (Na + ,K + - and Mg 2+ - ATPase), that seemed to take place in a CNS-region-specific manner and that were dependent upon the PTU-exposure timeframe followed. As these findings are analyzed and com- pared to the available literature, they: (i) highlight the vari- ability involved in the changes of the aforementioned enzy- matic parameters in the studied CNS regions (attributed to both the different neuroanatomical composition and the thyroid-hormone-dependent neurodevelopmental growth/ differentiation patterns of the latter), (ii) reveal important information with regards to the neurochemical mechanisms that could be involved in the way clinical hypothyroidism could affect optimal neurodevelopment and, ultimately, cog- nitive function, as well as (iii) underline the need for the adoption of more consistent approaches towards the experi- mental simulation of congenital and early-age-occurring hypothyroidism. Keywords Hypothyroidism . Propylthiouracil . Gestation . Lactation . Acetylcholinesterase . Na + ,K + -ATPase . Mg 2+ -ATPase . Rat . Frontal cortex . Hippocampus Abbreviations AChE acetylcholinesterase ATPases adenosine-triphosphatases CNS central nervous system FC frontal cortex Hi hippocampus Konstantinos Kalafatakis and Apostolos Zarros are authors with equal contribution to the study C. Koromilas : A. Bimpis : C. Liapi Laboratory of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece C. Koromilas : S. Tsakiris (*) : K. Kalafatakis : A. Zarros : V. Stolakis : D. Kimpizi : A. Bimpis : A. Tsagianni Laboratory of Physiology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias str., GR-11527, Athens, Greece e-mail: stsakir@gmail.com K. Kalafatakis Henry Wellcome Laboratories for Integrative Neuroscience & Endocrinology, School of Clinical Sciences, Faculty of Medicine & Dentistry, University of Bristol, Bristol, UK A. Zarros Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK A. Bimpis St. Mary’ s Hospital, Imperial College Healthcare NHS Trust, London, England, UK Metab Brain Dis (2015) 30:241–246 DOI 10.1007/s11011-014-9581-9