I came across the same article in Tuesdays ScienceTime’s, and what peaked my interest was the involvement of the unnamed proteins released during development and the role they play in the differentiation of nerve cells. In contemplating this I recalled (from intro bio) that certain hormones are able to stimulate neurons to increase the number of synapses the neurons receive. In this category were sex hormones, which have powerful effects on the development of the brain and behavior in human beings, and affect behavior throughout development. Changes in the sensitivity of neurons, due to these hormones are presumed to bring about changes in neural circuitry and sexual behavior. I would be interested in investigating this further; how hormones affect neural circuitry and what could result from isolating that effect