New findings on brain cells controlling fertility

Tuesday 23 June 2009
New findings on brain cells controlling fertility

Latest University of Otago findings on the brain circuitry controlling fertility in humans may open the way for the development of new treatments in the area.

A newly-published paper by Centre for Neuroendocrinology investigators Professor Allan Herbison and Dr Rebecca Campbell is clearing up the mystery of how brain cells with master control over fertility coordinate to perform their vital role.

Their research focuses on a small and relatively scattered population of cells known as gonadotropin-releasing hormone (GnRH) neurons, whose mode of communication has been unknown until now.

Study leader Professor Allan Herbison says that the 1000 or so GnRH neurons act in unison to send out pulses of a hormone responsible for the cascade of events in the body that allow ovulation and other related processes to occur.

“Without these regular pulses of hormone being secreted into the bloodstream – which occurs roughly once every hour or so – the downstream processes enabling fertility simply cannot go ahead.”

Using state-of-the-art imaging techniques in mice, the researchers found strong evidence that GnRH neurons interact in an unusual way.

“In contrast to most other neurons, which rely on chemical synapses to communicate with each other, GnRH neurons instead appear to be interconnected through very long branch-like protrusions known as dendrites.

“Now that we have this new understanding of how GnRH neurons interact to generate these crucial pulse patterns, this presents exciting possibilities for developing novel therapies involving agents that selectively control this activity.”

Professor Herbison says that the need for new treatments for infertility is becoming ever more pressing, with rates predicted to continue to rise in western societies.

“In New Zealand, the current estimate is that 15-20 per cent of couples are infertile. It is also thought that around one-third of all cases of infertility in women are due to disorders in brain control mechanisms.”

The study appears in the latest issue of the prestigious US journal Proceedings of the National Academy of Sciences (PNAS). The researchers’ work was supported with funding from the New Zealand Health Research Council.

ENDS