Genetic influences on hippocampal volume differ as a function of testosterone level in middle-aged men

Matthew S. Panizzon, Richard L. Hauger, Lindon J. Eaves, Chi-Hua Chen, Anders M. Dale, Lisa T. Eyler, Bruce Fischl, Christine Fennema-Notestine, Carol E. Franz, Michael D. Grant, Kristen C. Jacobson, Amy J. Jak (+8 others)
2012 NeuroImage  
The hippocampus expresses a large number of androgen receptors; therefore, in men it is potentially vulnerable to the gradual age-related decline of testosterone levels. In the present study we sought to elucidate the nature of the relationship between testosterone and hippocampal volume in a sample of middle-aged male twins (average age 55.8 years). We found no evidence for a correlation between testosterone level and hippocampal volume, as well as no indication of shared genetic influences.
more » ... wever, a significant moderating effect of testosterone on the genetic and environmental determinants of hippocampal volume was observed. Genetic influences on hippocampal volume increased substantially as a function of increasing testosterone level, while environmental influences either decreased or remained stable. These findings provide evidence for an apparent gene-by-hormone interaction on hippocampal volume. To the best of our knowledge, this is the first study to demonstrate that the heritability of a brain structure in adults may be modified by an endogenous biological factor.
doi:10.1016/j.neuroimage.2011.09.044 pmid:21983185 pmcid:PMC3230702 fatcat:rwjrzsqrlfgvdnbbk6chtiqz5m