The thematic of my team concerns the study of the neural bases of some behavior, as locomotor activity and more recently of olfaction, using a genetically tractable model system, the Drosophila. We use pluridisciplinary approaches, from genes characterization (molecular cloning) up to the whole integrated function, the locomotor activity and olfaction.
Methodologically, this implies the genetic and molecular biology, the neuroanatomy, the behavioral analysis and recently, the in-vivo functional brain imaging, by a bioluminescence approach. We have developed a video-tracking paradigm permitting to precisely quantifying the locomotor activity and allowing revealing its multiple complex parameters. More recently, we have develop a new in-vivo brain imaging approach, in bioluminescence, based on a chimeric protein (GFP-aequorin), allowing to record the neuronal activity.
Three axes are currently studied, in parallel :
in-vivo functional brain imaging, by bioluminescence(picture).
This technique allows recording the neuronal calcium activity, in-vivo, in continue, from different brain structures, either superficially or deeply located, in semi-behavioral conditions. This approach opens several perspectives, as :
a) characterization of the olfactory response following natural stimuli (odors), at different levels of the olfactory circuitry : first, in the olfactory receptor neurons (ORNs) in the antennal lobes, second, in the projections neurons (PNs), and third, in the Mushrooms-bodies (a structure implicated in the olfactory learning and memory). More particularly, we have described an olfactory adaptation process occurring in the axon terminal of the ORNs (within the antennal lobes), and we are currently characterizing such physiological phenomenon.
b) characterization of the delayed secondary response specifically in the Mushroom-Bodies lobes (axonal projections) induced by the nicotine (an acetylcholine agonist).
c) characterization of the neuronal activity in the ellipsoid-body, in relation to the locomotor activity.
d) Construction of anatomo-functionnal maps (build a functional Atlas) of the general activity (spontaneous or induced) of the overall brain considered as an ensemble, through a pan-neuronal expression of the GFP-aequorin.
Study of the role of the Central Complex (a premotor center) through the genetic and molecular characterization of the line P[GAL4]4C, specifically expressed in the ellipsoid-body (a substructure of the Central complex) (picture).
Characterization of the brain structures implicated in the centrophobism and in the thigmotaxis, two components of the spatial orientation (picture).