94% of researchers rate our articles as excellent or good
Learn more about the work of our research integrity team to safeguard the quality of each article we publish.
Find out more
ORIGINAL RESEARCH article
Front. Neurosci.
Sec. Neuroendocrine Science
Volume 19 - 2025 | doi: 10.3389/fnins.2025.1477725
This article is part of the Research Topic New Advances in Biomedical Research on Sex, Gender & Gender Incongruence View all 4 articles
Hippocampal subfield volume differences between femaleto-male transgender individuals with cross-sex hormone therapy and cisgender women
Provisionally accepted- 1 Chonnam National University, Gwangju, Republic of Korea
- 2 Chonnam National University Medical School, Gwangju, Gwangju, Republic of Korea
The prevalence of female-to-male (FtM) transgender individuals has risen recently, yet the effects of cross-sex hormone therapy on volumetric differences in the hippocampal subfields remain poorly understood. This study aimed to evaluate the differences of gray matter (GM) volume, especially focusing on the hippocampal subfields, in FtM transgender individuals and premenopausal cisgender women. Seventeen FtM transgender individuals who had undergone hysterectomies and were receiving testosterone therapy before participating in this study, along with 20 premenopausal women, underwent a single session of T1-weighted magnetic resonance imaging (MRI). FtM transgender group had significantly higher free-testosterone (free-T) levels and lower estradiol levels compared with premenopausal women group (p < 0.001). In voxel-wise analysis, FtM transgender individuals showed significantly larger GM volumes in the caudate nucleus, hypothalamus, and thalamus compared with premenopausal women (p < 0.01, FWE-corrected). More specifically, the right hippocampal subiculum volume was larger in FtM transgender individuals (p < 0.05, Bonferroni-corrected), and these volumes were positively correlated with the free-T levels (r = 0.34, p = 0.04). This study revealed the specific hippocampal subfield volume differences in the testosterone-treated FtM transgender group when compared to cisgender premenopausal women group. These findings might help elucidate the morphological variation of the specific cerebral regions associated with testosterone therapy in FtM transgender individuals and contribute to our understanding of the effects of gender-affirming hormone treatments as well.
Keywords: brain volume, female-to-male transgender individuals, hippocampal subfields, hormone therapy, Testosterone
Received: 08 Aug 2024; Accepted: 12 Feb 2025.
Copyright: © 2025 Kim, Lee, Lee, Park and Jeong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Mina Lee, Chonnam National University Medical School, Gwangju, 61469, Gwangju, Republic of Korea
Hyun Sook Lee, Chonnam National University Medical School, Gwangju, 61469, Gwangju, Republic of Korea
Kwangsung Park, Chonnam National University Medical School, Gwangju, 61469, Gwangju, Republic of Korea
Gwang-Woo Jeong, Chonnam National University Medical School, Gwangju, 61469, Gwangju, Republic of Korea
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.