In their studies, the researchers found neural circuits that coordinate a complex interplay between neurons that control reproduction and brain areas that carry the neural signals triggered by odorant molecules and those triggered by pheromones, chemical signals produced by animals. The researchers characterize their findings as an initial step in understanding the far-reaching influence that odors and pheromones may have on reproduction and other behaviors.
The research team, which was led by HHMI investigator Linda B. Buck at the Fred Hutchinson Cancer Research Center, included first author Ulrich Boehm and Zhihua Zou, who did the work as postdoctoral fellows while in Buck's lab. The researchers published their studies in an immediate early publication on November 10, 2005, in the journal Cell. Related studies by HHMI investigator Catherine Dulac are published in the same issue.
The scientists began their studies by focusing on tracing the neural pathways leading to and from neurons that produce gonadotropin releasing hormone (GnRH), which is also known as luteinizing hormone releasing hormone (LHRH). These neurons regulate sexual physiology -- including onset of puberty, ovulation, and the menstrual cycle in females and testosterone production in males -- by regulating the release of hormones from the pituitary gland. Interestingly, GnRH neurons also appear to be involved in the control of sexual behaviors.
"Consistent with the idea that GnRH neurons might have additional functions beyond controlling the pituitary, other investigators have shown that GnRH axons can be found in many different areas of the brain," said Buck. "Those findings suggested that GnRH neurons were sending signals to other neurons, but the neurons that rec
Source:Howard Hughes Medical Institute