Chronobiology
Author: Juan Ignacio Ispizua | email: ispizua.juan@gmail.com
Juan Ignacio Ispizua 1°, Magdalena Fernandez-Acosta 1°, Maria Fernanda Ceriani 1°
1° Laboratorio de Genética del Comportamiento. Fundación Instituto Leloir – IIBBA – CONICET, Buenos Aires, C1405BWE, Argentina
Recently, we described that a functional glial clock is necessary for circadian plasticity in the small lateral ventral neurons (sLNvs), a group of key pacemaker neurons of D. melanogaster. Circadian structural plasticity involves rhythmic changes in the arborization pattern and degree of fasciculation of their dorsal termini. sLNvs expresses PDF, a neuropeptide relevant in clock network synchrony that oscillates in phase with this remodelling process. Circadian plasticity modifies the way the pacemaker circuitry is wired regularly, but its impact on behaviour and the molecular basis that control this process are yet to be defined. Building upon those results, we started to look in depth this neuronal-glial relationship. Using GFP reconstitution analysis, we found that these termini contact directly two different glial subtypes (astrocyte-like and ensheathing glia) and that these contacts are time-of-the-day dependent. Interestingly, using thermosensitive shibire (shiTS) to induce adult glio-transmission blockage has different effects on PDF levels and plasticity depending on the type of glia affected and the length of the treatment (12 or 24 hours). Digging into possible glio-transmitters responsible for that phenotype, we found that silencing Maverick, a BMP pathway ligand, mimics the effects of shiTS treatment. Taken together, our results suggest a complex glial implication in the modulation of adult structural plasticity with distinct roles for different glial subtypes.