Early-onset sleep defects in Drosophila models of Huntington's disease reflect alterations of PKA/CREB signaling.

Huntington's disease (HD) is a progressive neurological disorder whose non-motor symptoms include sleep disturbances. Whether sleep and activity abnormalities are primary molecular disruptions of mutant Huntingtin (mutHtt) expression or result from neurodegeneration is unclear. Here, we report Drosophila models of HD exhibit sleep and activity disruptions very early in adulthood, as soon as sleep patterns have developed.

Spatio-temporal in vivo recording of dCREB2 dynamics in Drosophila long-term memory processing.

CREB (cAMP response element-binding protein) is an evolutionarily conserved transcription factor, playing key roles in synaptic plasticity, intrinsic excitability and long-term memory (LTM) formation. The Drosophila homologue of mammalian CREB, dCREB2, is also important for LTM. However, the spatio-temporal nature of dCREB2 activity during memory consolidation is poorly understood.

Time of day influences memory formation and dCREB2 proteins in Drosophila.

Many biological phenomena oscillate under the control of the circadian system, exhibiting peaks and troughs of activity across the day/night cycle. In most animal models, memory formation also exhibits this property, but the underlying neuronal and molecular mechanisms remain unclear. The dCREB2 transcription factor shows circadian regulated oscillations in its activity, and has been shown to be important for both circadian biology and memory formation.

ERK phosphorylation regulates sleep and plasticity in Drosophila.

Given the relationship between sleep and plasticity, we examined the role of Extracellular signal-regulated kinase (ERK) in regulating baseline sleep, and modulating the response to waking experience. Both sleep deprivation and social enrichment increase ERK phosphorylation in wild-type flies. The effects of both sleep deprivation and social enrichment on structural plasticity in the LNvs can be recapitulated by expressing an active version of ERK (UAS-ERK(SEM)) pan-neuronally in the adult fly using GeneSwitch (Gsw) Gsw-elav-GAL4.

In vivo circadian oscillation of dCREB2 and NF-κB activity in the Drosophila nervous system.

cAMP response element-binding protein (CREB) and nuclear factor kappa-B (NF-κB) are two ubiquitous transcription factors involved in a wide number of cellular processes, including the circadian system. Many previous studies on these factors use cellular assays that provide limited information on circadian activity or anatomical specificity. The ability to study transcription factors in defined tissue within intact animals will help to bridge the gap between cellular and in vivo data.

Autoreceptor control of peptide/neurotransmitter corelease from PDF neurons determines allocation of circadian activity in drosophila.

Drosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral-ventral pacemaker neurons (LN(v)s) that secrete the neuropeptide PDF (pigment dispersing factor). Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR)-expressing dorsal clock neurons in organizing circadian activity.

Memory formation: filling in the gaps in flies.

Research in Drosophila has many advantages for the study of complex behavior. Two studies identify a new role for chemical and electrical signaling in the anterior paired lateral neurons during memory formation.