New treatments for infertility could be in the pipeline

New research by New Zealand scientists may eventually lead to new treatments for infertility.

Scientists at the University of Otago have found in their research into the brain circuits which control human fertility, that instead of the usual synapses, fertility is controlled by a thousand or so special neurons, which are linked by long, branch-like dendrites and they believe their discovery could lead to the development of new treatments for infertility.

The new research by Professor Allan Herbison and Dr Rebecca Campbell from the University's Centre for Neuroendocrinology, helps to unravel the mystery of how brain cells with master control over fertility, coordinate to perform their vital role.

In their research they focused on a small and relatively scattered population of cells known as gonadotropin-releasing hormone (GnRH) neurons, whose mode of communication has been hitherto unknown.

Professor Herbison says that the 1,000 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 and without these regular pulses of hormone being secreted into the bloodstream every hour or so - the downstream processes enabling fertility simply cannot go ahead.

Professor Herbison who led the research says strong evidence that GnRH neurons interact in an unusual way in mice was revealed by using state-of-the-art imaging techniques.

Professor Herbison says 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 and this new knowledge on how GnRH neurons interact to generate these crucial pulse patterns, presents exciting possibilities for developing novel therapies involving agents that selectively control this activity.

He 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% of couples are infertile and it is suspected that around one-third of all cases of infertility in women are due to disorders in brain control mechanisms.

The research which appears in the latest issue of the journal Proceedings of the National Academy of Sciences was supported with funding from the New Zealand Health Research Council.