Whether CNS glial cells play an important role in the regulation of complex behaviors has been a longstanding question. In this issue of Neuron, Suh and Jackson demonstrate a circadian rhythmicity in glial expression of ebony, an N-beta-alanyl-biogenic amine synthase, and show that Ebony activity in glia is essential for the proper regulation of Drosophila circadian behavior.

Intelligent agents must select and apply rules to accomplish their goals. In this issue of Neuron, Buschman et al. (2012) demonstrate that oscillatory neuronal coupling is key to rule processing in monkey prefrontal cortex, notably when rules change during tasks.

Biological rhythms with periods of less than a day are physiologically important but poorly understood. In this issue of Cell, Norman, Maricq, and colleagues (Norman et al., 2005) show that VAV-1, a guanine nucleotide exchange factor for Rho-family GTPases, is necessary for three rhythmic behaviors in the nematode Caenorhabditis elegans: feeding, defecation, and ovulation.