Synthia Mellon, PhD

Department of Obstetrics Gynecology & Reproductive Sciences

Our laboratory studies the regulation of steroid hormone synthesis, by analyzing the transcriptional regulation of the steroidogenic enzymes, and the mechanism of action of steroids in both steroidogenic tissues and in the nervous system, where we identified the developmental and regional expression of steroidogenic enzymes and some novel actions of steroids on neuronal function. Steroid hormones are regulators of a multitude of physiologic processes, and act primarily by activating nuclear receptors, which are transcriptional regulators of various genes. However in the nervous system, where we found steroidogenic enzymes and synthesis of a novel class of steroid, called neurosteroids, neurosteroids modulate ion flux through the ion gated GABA A and NMDA receptors, and regulation of their synthesis results in changes in behavior, learning, and memory. We delineated the ontogeny and sites of steroidogenic enzyme expression , and showed that neurosteroids affect neuronal development by specifically modulating either axonal or dendritic growth and neuronal differentiation.Their actions throughout life may maintain the integrity of neural connections, and demise of neurosteroid synthesis may result in loss of memory associated with some age-related neurologic diseases. Our studies thus rely on a number of different experimental paradigms, from molecular biologic analysis of gene structure and transcription factors to developmental and cell biology of neuronal development and function.

Primary Thematic Area: 
Developmental & Stem Cell Biology
Secondary Thematic Area: 
Research Summary: 
Developmental Regulation, Molecular Biology and Novel Actions of Steroid/Neurosteroid Synthesis

Posttraumatic stress disorder, symptoms, and white matter abnormalities among combat-exposed veterans.

Brain imaging and behavior

Aschbacher K, Mellon SH, Wolkowitz OM, Henn-Haase C, Yehuda R, Flory JD, Bierer LM, Abu-Amara D, Marmar CR, Mueller SG

Telomere length is inversely correlated with urinary stress hormone levels in healthy controls but not in un-medicated depressed individuals-preliminary findings.

Journal of psychosomatic research

Fair B, Mellon SH, Epel ES, Lin J, Révész D, Verhoeven JE, Penninx BW, Reus VI, Rosser R, Hough CM, Mahan L, Burke HM, Blackburn EH, Wolkowitz OM

Severity of anxiety- but not depression- is associated with oxidative stress in Major Depressive Disorder.

Journal of affective disorders

Steenkamp LR, Hough CM, Reus VI, Jain FA, Epel ES, James SJ, Morford AE, Mellon SH, Wolkowitz OM, Lindqvist D

Biological predictors of insulin resistance associated with posttraumatic stress disorder in young military veterans.


Blessing EM, Reus V, Mellon SH, Wolkowitz OM, Flory JD, Bierer L, Lindqvist D, Dhabhar F, Li M, Qian M, Abu-Amara D, Galatzer-Levy I, Yehuda R, Marmar CR

Higher serum DHEA concentrations before and after SSRI treatment are associated with remission of major depression.


Hough CM, Lindqvist D, Epel ES, Denis MS, Reus VI, Bersani FS, Rosser R, Mahan L, Burke HM, Wolkowitz OM, Mellon SH