H. F. Clarke, S. C. Walker, H. S. Crofts, J. W. Dalley, T. W. Robbins, and A. C. Roberts
Inflexibility in responses to stimuli is characteristic of frontal lobe injury as well as schizophrenia and depression. Based on lesion studies, different regions of prefrontal cortex (PFC) have been implicated in such executive" functions. This week, Clarke et al. asked marmosets to turn their attention to a setshifting task. After 5,7-dihydroxytryptamine-induced depletion of serotonin in the PFC, the monkeys' ability to set-shift remained unimpaired. The results predict differential actions of serotonin modulation (e.g., by selective serotonin reuptake inhibitors) on frontal lobe functions.
2. Blocking Aß-Stimulated Inflammation with Statins
Andrew Cordle and Gary Landreth
This week, Cordle and Landreth examine a novel action of statins beyond their well known ability to lower cholesterol. Statins work by inhibiting the rate-limiting enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase in cholesterol synthesis. Population studies in humans also indicate that statins decrease the risk of Alzheimer's disease. The authors suggest that the effect of statins in AD may be antiinflammatory rather than just lipid-lowering.