Molecular Underpinnings of Sexual Dimorphism in the CNS

Sexual dimorphism, as a topic, has been investigated extensively by neuroscientists at the level of brain structures, but the molecular underpinnings of these sex differences have received much less attention. Below is a short post summarizing the state of affairs in this regard. The information is derived from an excellent 2010 review by Jazin & Cahill published in Nature Reviews: Neuroscience.

Perhaps the most fascinating development in molecular studies of CNS sexual dimorphism is the focus on sex-biased gene expression. Gene expression differences which appear to be independent of hormone action have been found in rodents and in certain invertebrates, notably the fruitfly, D. melanogaster, and the nematode, C. elegans. In the latter two, there are even sex-specific neuronal networks governing mating/courtship behaviors.