Medial temporal subregion volume changes observed over the course of a human pregnancy

• In Event: Parents develop, too: Maternal and Paternal Neural Reorganization Across the Perinatal Period

Abstract

Animal studies offer unambiguous evidence that sex steroid hormones shape the synaptic organization of the mammalian brain. Yet human neuroscience has almost entirely ignored how the brain responds to major changes in sex hormone production (e.g. during the menstrual cycle, pregnancy, or menopause). Pregnancy, a period of profound hormonal and physiological change, is experienced by the majority of women at least once in their lifetime, yet very few neuroimaging studies of the maternal brain have been conducted in humans. The existing literature suggests significant and persistent reductions in gray matter volume across a network of regions that support social cognition and theory of mind, including the hippocampus (Hoekzema et al., Nature Neuroscience, 2017; Martínez-García et al., Brain Sciences, 2021). Here, we report findings from a dense-sampling study of the maternal brain (n=1, 24 scans from -5 weeks to 91 weeks relative to conception) to examine how the surge in sex steroid hormones over the gestational window shapes medial temporal lobe morphology in a human. Using high-resolution imaging and segmentation of the hippocampus and surrounding tissue, we observed significant changes in parahippocampal cortex volume, specific to pregnancy, that corresponded with serum measurements of estradiol and progesterone.

Authors

• Caitlin M. Taylor, University of California, Santa Barbara, CA
  Presenting Author

• Elizabeth R. Chrastil, University of California, Irvine, CA

• Emily G. Jacobs, University of California, Santa Barbara