3. CCK and the Nocebo Effect
Fabrizio Benedetti, Martina Amanzio, Sergio Vighetti, and Giovanni Asteggiano
The placebo effect needs no introduction: give patients a "sugar pill" along with a suggestion that it will cure their symptoms, and they feel better. But the opposite occurs if the pill is given with a suggestion that the symptoms will get worse. Benedetti et al. tested this lesser studied phenomenon, the nocebo effect, on physical pain induced by restricting forearm blood flow with a tourniquet during exercise. As expected, giving study volunteers an inert pill that they were told would increase pain, in fact did so. This nocebo effect was coupled with increases in circulating markers of hypothalamicpituitary adrenal (HPA) axis activity. Diazepam blocked the increase in both HPA markers and pain sensitivity, whereas proglumide, an antagonist of cholecystokinin receptors, blocked only the pain effects. Thus, it seems that nocebo suggestions induce anticipatory anxiety, leading to hyperactivity of the HPA axis. Anxiety then activates cholecystokinin signaling that increases pain transmission.
4. SCAM Analysis of the ?-Secretase Catalytic Domain
Chihiro Sato, Yuichi Morohashi, Taisuke Tomita, and Takeshi Iwatsubo
Like molecular scissors, proteases chop proteins in pieces. Because they hydrolyze peptide bonds with water, the catalytic domains of these enzymes are usually located within aqueous compartments and thus are "self-lubricating." But som
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Society for Neuroscience