Such studies will provide a genes-to-circuit-to-behavior integration, and also a place in the brain to look for behaviorally relevant regulatory effects. Although the initial acquisition of courtship memory, like olfactory memory, appears to occur in MB, through the activation of dopamine receptors in the MB γ neurons (Keleman et al., 2012; Qin et al., 2012), the site

of de novo gene expression underlying olfactory memory has recently been localized outside of MB (Chen et al., 2012). With courtship memory, GAL4-mediated overexpression of either Orb2A or Orb2B in MB neurons is sufficient to rescue the memory defect in orb2 mutants that lack the glutamine-rich domain ( Keleman et al., 2007). Therefore, to formally demonstrate that Orb2A-mediated oligomer formation and subsequent CPEB-dependent local translational regulation Temozolomide research buy are induced selleck kinase inhibitor selectively in MB γ neurons, it will be important to rescue the mutant alleles with Orb2A glutamine-rich domain and Orb2B RNA binding domain each restricted to γ neurons. Finally, the mechanistic details of local translation will likely involve other regulatory molecules,

some of which have already been implicated in memory and plasticity in Drosophila ( Barbee et al., 2006; Dubnau et al., 2003). A protein of particular interest is Pumilio, another RNA binding protein whose function is required for long-term olfactory aversive memory ( Dubnau et al., 2003) and which also contains an aggregation-prone prion-like domain ( Salazar et al., 2010). An understanding of the function of prion-like proteins in normal neuronal physiology will provide context to decipher the impact of pathological effects of aggregation prone prion-like proteins in neurodegenerative disorders. “
“The brain processes sensory information through the combined activity of large numbers of neurons. Until fairly recently, it was only possible to record from neurons one a time. These recordings have revealed much about sensory coding and enabled from scientists to hypothesize how larger neuronal

populations might represent sensory stimuli. Now that techniques such as two-photon imaging and multichannel electrophysiology allow hundreds of neurons to be recorded simultaneously, one can directly see how moderately sized neuronal populations actually operate. The brain, of course, works the same way however many neurons an experimenter manages to record from, so any population recording must be consistent with what was earlier seen at the single neuron level. Nevertheless, the results of population recordings often contradict hypotheses that had been inferred from single neuron studies. In this issue of Neuron, Bathellier et al. (2012) provide an excellent example of this, in a study of population coding in the superficial layers of mouse auditory cortex.