Identification of fast neurotransmitter(s) in the central pacemaker of the Drosophila brain

FRENKEL, L; CERIANI, MF

Huerta Grande

Congreso; XXVII Congreso de la Sociedad Argentina de Neurociencias; 2011

Sociedad Argentina de Neurociencias

The circadian clock is a temporal filter. Based on self-sustaining transcriptional negative feedback loops, it ultimately gives rise to rhythms in physiology and behavior. Molecular oscillators are hierarchically organized: one is a pacemaker and the others are slaves. Circadian control of clock outputs ranges from the most immediate ones within pacemaker neurons to the circadian modulation of different behaviors. In the Drosophila adult brain, the small ventral lateral neurons (sLNvs) constitute the central pacemaker. It comprises five cells, of which four rhythmically release the neuropeptide pigment dispersing factor (PDF). PDF triggers specific (i.e., resetting) signaling events in downstream targets. The presence of small clear vesicles near synaptic output sites in the axonal terminals of the sLNvs suggests that additional fast neurotransmitter(s) (NT) could take part in this process. Still, there is no clear candidate NT in the sLNv cells as they are not immunoreactive either to several biogenic amines or to GABA. The goal of this work (which is still in progress) is to evidence the nature of this NT; the methodology consists of downregulating the expression of NT re-uptakers in the PDF+ neurons and screening for changes in two clock outputs: daily structural remodelling of PDF axonal projections and rhythmic locomotor activity.