Sex Ends As Seasons Shift And Kisspeptin Levels Plummet:
A hormone implicated in the onset of human puberty also appears to control reproductive activity in seasonally breeding rodents, report Indiana University Bloomington and University of California at Berkeley scientists in the March 2007 issue of Endocrinology. The paper is now accessible online via the journal's rapid electronic publication service. The researchers present evidence that kisspeptin, a recently discovered neuropeptide encoded by the KiSS-1 gene, mediates the decline of male Siberian hamsters' libido and reproduction as winter approaches and daylight hours wane.
Research Upsetting Some Notions About Honey Bees:
Genetic research, based on information from the recently released honey bee genome, has toppled some long-held beliefs about the honey bee that colonized Europe and the U.S.
According to research published recently in Science, an international professional journal published by the American Association for the Advancement of Science, the four most common subspecies of honey bee originated in Africa and entered Europe in two separate migrations, said Dr. Spencer Johnston, entomologist with the Texas Agricultural Experiment Station and one of the authors of the article.
A large number of different bee species exist in Asia, where it had long been thought the honey bee originated, Johnston said.
"Their origin in Africa was suggested in other studies, but our result shows it dramatically to be true," he said.
Researchers Discover New Species Of Fish In Antarctic:
What's 34 centimeters (13.39 inches) long, likes the cold and has an interorbital pit with two openings? The answer is Cryothenia amphitreta, a newly discovered Antarctic fish discovered by a member of a research team from the University of Illinois at Urbana-Champaign.
Complexity Constrains Evolution Of Human Brain Genes:
Despite the explosive growth in size and complexity of the human brain, the pace of evolutionary change among the thousands of genes expressed in brain tissue has actually slowed since the split, millions of years ago, between human and chimpanzee, an international research team reports in the December 26, 2006, issue of the journal, PLOS Biology.
How Many Genes Does It Take To Learn? Lessons From Sea Slugs:
Scientists analyzing the genomics of a marine snail have gotten an unprecedented look at brain mechanisms, discovering that the neural processes in even a simple sea creature are far from sluggish. At any given time within just a single brain cell of sea slug known as Aplysia, more than 10,000 genes are active, according to scientists writing in Friday's (Dec. 29, 2006) edition of the journal Cell. The findings suggest that acts of learning or the progression of brain disorders do not take place in isolation - large clusters of genes within an untold amount of cells contribute to major neural events.
Watching With Intent To Repeat Ignites Key Learning Area Of Brain:
Watch and learn. Experience says it works, but how? University of Oregon researchers have seen the light, by imaging the brain, while test subjects watched films of others building objects with Tinker Toys. As detailed in the Dec. 20 issue of the Journal of Neuroscience, researchers, using functional magnetic resonance imaging, found that when a person watches someone else perform a task with the intention of later replicating the observed performance, motor areas of the brain are activated in a fashion similar to that with accompanies actual movement.
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