The surprising effects of acute downregulation of a GABA receptor in Drosophila sleep behavior

NARA I MURARO; FLORENCIA FERNANDEZ

Mar del Plata

Congreso; XXXII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2017

Sociedad Argentina de Investigación en Neurociencias

Sleep is a complex and vital behavior regulated by both, circadian and homeostatic mechanisms. The so called sleep homeostat is responsible for sensing the sleep debt that is accumulated during wake. The neural circuits involved in sleep homeostasis are not well described yet, but it has been suggested that GABAergic inputs to the large lateral ventral neurons (lLNvs) of the adult brain of Drosophila melanogaster may have the role of informing those arousal neurons about the sleep homeostat status.Starting from this point, our aim was to analyze the mechanisms of GABAergic inhibition on those neurons, their influence on sleep behavior and their role on the sleep homeostat. For this, we quantified sleep behavior by inferring it from locomotor activity. In addition, we studied the circadian neuropeptide PDF (pigment dispersing factor) levels in the axonal projections of the lLNvs in order to evidence the effect over neuronal outputs under those circumstances.Our findings indicate that downregulation of the GABAA receptor Rdl in the LNvs affects sleep behavior in the way it was previously reported. Moreover, we have now confirmed its previously suggested role on the sleep homeostat. However, we have surprisingly found that sleep can be differentially affected by the downregulation of Rdl in the LNvs when the genetic manipulation is performed in a constitutive or an acute way, opening unexpected possibilities of their mechanism of action.