Volume 6 Issue 10, October 2003

A homeostatic control mechanism that monitors and reacts to the need for sleep has been thought to function independently of the brain's circadian clock in previous studies. Now simultaneous recordings of sleep stages and electrical activity in the suprachiasmatic nucleus in behaving animals reveal feedback from sleep centers to the circadian pacemaker.

How is synaptic facilitation mediated? New work suggests that a calcium-sensing molecule, neuronal calcium sensor-1 (NCS-1) transduces a residual calcium signal into an enhancement of transmitter release at excitatory synapses in the hippocampus.

HIV-associated neurodegeneration likely involves release of signals from activated glial cells. A new study reveals that matrix metalloproteinase from HIV-1-infected macrophages or microglia cleaves the chemokine SDF-1 to generate a potent neurotoxin.

Corticotropin releasing factor (CRF) is a critical integrator of the central stress response. A new study now provides conclusive evidence that CRF-mediated forebrain activation underlies the behavioral response, such as anxiety, to stress.