Volume 8 Issue 6, June 2005

Hormonal changes during the estrous cycle have profound effects on synaptic transmission, from altering the density of synapses to changing receptor composition. A new paper shows that neurons express different subsets of GABA_A receptor subunits during different phases of the estrous cycle, and that this alters tonic inhibition, seizure susceptibility and anxiety in female mice.

A study in this issue describes the first multipotent stem cell identified in the postnatal cerebellum. These cells can generate inhibitory interneurons, astrocytes and oligodendrocytes. They may also be responsible for a class of childhood brain tumors.

How do genes act in the brain to influence susceptibility to mental illness? An imaging study suggests that healthy carriers of a gene variant associated with depression risk have decreased brain volume and neural coupling in affective circuitry involved in depression.

Sleep deprivation causes all too familiar behavioral impairments and increased need for sleep. A new Drosophila mutant with alterations in the Shaker potassium channel sleeps less than normal but does not show the usual effects of sleep deprivation.

How do we form arbitrary associations, such as 'stop at red' or 'go at green'? A report in Nature suggests that these associations are first formed in the striatum but that activity changes in the prefrontal cortex are more closely related to improved performance.