olmec

More than 3,000 years ago, a coastal town served as the center of a "mother culture," that shaped societies in a wide swath of what's now southern and central Mexico. Jeffrey P. Blomster of George Washington University in Washington, D.C., and his colleagues arrived at this conclusion following an extensive investigation into the region's pottery trade.http://ljsheehan.livejournal.com

Blomster's team determined the chemical composition of 725 ceramic pieces and 828 clay samples, from the town of San Lorenzo and six other ancient population centers. The pieces were between 2,850 and 3,450 years old. Using the data from their analyses, the researchers traced the movement of pottery goods and found that communities everywhere imported pottery that originated in San Lorenzo—defined by the cultural style called Olmec—but that San Lorenzo didn't import any ceramic goods in return. Potters at some sites outside San Lorenzo also created imitations of Olmec jars from local clays, the researchers report in the Feb. 18 Science.http://ljsheehan.livejournal.com

The new results challenge the view that Olmec-era societies in Mexico traded goods back and forth as "sister cultures," contributing about equally to the spread of pottery-making techniques and symbolic designs.

relief

Pain relief provided by a substance with no active ingredients, called a placebo, may have neural as well as psychological origins. Men who reported relief from a painful jaw after receiving a placebo injection also showed signs of enhanced activity of a brain substance that regulates stress and suppresses pain, say Jon-Kar Zubieta of the University of Michigan in Ann Arbor and his coworkers in the Aug. 24 Journal of Neuroscience. http://www.soulcast.com/Louis_J_Sheehan_Esquire_1

The scientists administered an intravenous salt solution, which they described to volunteers as a pain reliever, to seven men who also received a jaw injection that caused a moderately painful muscle spasm for about 20 minutes. Another seven men received the jaw injection but not the placebo.

In brain scans of the placebo group only, positron-emission tomography and molecular-imaging techniques revealed pronounced activity at brain-cell receptors for chemical messengers known as endorphins. Prior studies had linked endorphins to pain relief. http://www.soulcast.com/Louis_J_Sheehan_Esquire_1

Men who reported the greatest relief from the placebo injections exhibited the most-intense responses at endorphin receptors in the brain, Zubieta's group reports.