Centrophobism/thigmotaxis, a new role for the mushroom bodies in Drosophila.
Insects, like vertebrates, exhibit spatially complex locomotor activity patterns when foraging or navigating. Open field studies recently showed that Drosophila avoids central zones and stays at the periphery, an effect that can be interpreted as centrophobism and/or thigmotaxis. In this study, we further characterized this phenomenon and studied the responsible underlying neural mechanisms. The implication of the Drosophila mushroom bodies (MBs) in olfactory learning and memory processes is well documented. In an open field situation in which fly locomotor activity is recorded by video tracking, we show that center avoidance is greatly diminished in flies with hydroxyurea-ablated MBs, suggesting a new role for these structures. Furthermore, the temperature-sensitive allele of the dynamin gene shibire was expressed in various enhancer-trap P[GAL4] lines, disrupting synaptic transmission in different MB lobes. Specifically blocking the gamma lobes alters centrophobism/thigmotaxis while blocking the alpha/beta lobes does not, suggesting a functional specialization of MB lobes. Drosophila may serve as a new model system for elucidating the genetic and neural bases of such complex phenomena as centrophobism/thigmotaxis.
Besson
Morgane
M
Bases Neurales du Mouvement chez la Drosophile, NAMC, CNRS, UMR-8620, Université Paris-Sud, F-91405 Orsay, France.
Martin
Jean-René
JR
D000704:Analysis of Variance; D000818:Animals; D030801:Animals, Genetically Modified; D001522:Behavior, Animal / Q000502:physiology*; D004195:Disease Models, Animal; D004330:Drosophila; D005260:Female; D006918:Hydroxyurea / Q000633:toxicity; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D024521:Mushroom Bodies / Q000187:drug effects / Q000293:injuries / Q000502:physiology*; D019384:Nucleic Acid Synthesis Inhibitors / Q000633:toxicity; D010698:Phobic Disorders / Q000139:chemically induced / Q000503:physiopathology; D012737:Sex Factors; D013697:Thermosensing / Q000235:genetics; D014741:Video Recording / Q000379:methods
D019384:Nucleic Acid Synthesis Inhibitors; D006918:Hydroxyurea