( petite feeding reward arousal and t...)The brain is broadly wired for reproduction

The studies also suggest that GnRH neurons influence a wide array of brain functions, possibly coordinating those functions with neuroendocrine status in order to optimize reproductive success, according to Buck.

Almost all the GnRH neuron-connected areas were identical in male and female mouse brains. However, there were some telltale sex differences in the circuitry, which offer important new pathways for investigating differences in male and female reproductive physiology and behavior, Buck said.

Although it is still early, the researchers suspect that the findings in mice could have implications for humans. "Because humans don't have a vomeronasal system, many have speculated that they may not detect pheromones," Buck said. "But these studies clearly indicate that the main olfactory system, which humans do have, is capable of transmitting pheromone signals. Therefore, if there are human pheromones -- although no one has yet identified one -- they would presumably transmit their signals through the main olfactory pathway."

Although the findings are considered a first step in exploring the GnRH reproduction-related circuitry in the brain, Buck acknowledges that they have already learned a great deal just by defining the circuits. "These findings now set the stage for studies in which the neurons in those circuits can be analyzed to determine the genes they selectively express. Then those genes can be used -- for example in gene knockout studies -- to determine what role the neurons play in reproduction and behavior," Buck said.

"Understanding how the brain's neural circuitry controls behavior has been largely a b
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Source:Howard Hughes Medical Institute