Photo of Prof. Rae Silver


Professor Rae Silver was invited to deliver the plenary Geoffrey Harris memorial lecture at the 2023 International Congress of Neuroendocrinology in Glasgow. The invitation was followed up by an article in which Rae Silver and her co-authors reviewed the landmark discoveries of Geoffrey Harris, who is generally considered the founder of the field of neuroendocrinology. Almost 100 years ago, Harris identified a portal pathway linking the hypothalamus and the pituitary gland in the brain. This pathway is necessary for life itself. Portal pathways are important because they enable low concentrations of neurosecretions to reach specialized local targets without dilution in the systemic circulation.

For decades, the pituitary portal system that Harris found was the only known portal pathway in the mammalian brain, until Professor Silver and her colleagues made another monumental discovery: the existence of a second portal pathway in the brain, with a venous pathway linking capillary blood vessels of the brain’s suprachiasmatic nucleus (SCN) to those of the organum vasculosum of the lamina terminalis (OVLT), a circumventricular organ.

Rae Silver and her colleagues provide a comprehensive overview of the parallels between Harris’s and their own paths to discovery and highlight the steps that will be needed going forward to understand the functions of this second portal pathway. The results also raise the question of whether there are many more such neurovascular communication pathways in the vertebrate brain.