1. Department of Cell Biology and the Department of Neurology, Baylor College of Medicine, Houston, Texas 77030, USA
2. Present addresses: Department of Biological Sciences, Columbia University, New York, New York 10027, USA (K.H.W.); Zentrum fur Molekulare Neurobiologie, Institut fur Neurale Signalverarbeitung, D-20246 Hamburg, Germany (X.-R.Z.)

Correspondence to: Ronald L. Davis¹ Correspondence and requests for materials should be addressed to R. L. Davis (e-mail: Email: rdavis@bcm.tmc.edu).The sequence has been deposited in EMBL/GenBank/DDBJ with accession numbers from AF034199 and AF034200.

Abstract

Volado is a new memory mutant of Drosophila. The locus encodes two isoforms of a new |[alpha]|-integrin, a molecule that dynamically mediates cell adhesion and signal transduction. The Volado gene is expressed preferentially in mushroom body cells, which are neurons known to mediate olfactory learning in insects. Volado proteins are concentrated in the mushroom body neuropil, brain areas that contain mushroom body processes in synaptic contact with other neurons. Volado mutants display impaired olfactory memories within 3|[thinsp]|min of training, indicating that the integrin is required for short-term memory processes. Conditional expression of a Volado transgene during adulthood rescues the memory impairment. This rescue of memory is reversible, fading over time along with expression of the transgene. Thus the Volado integrin is essential for the physiological processes underlying memory. We propose a model in which integrins act as dynamic regulators of synapse structure or the signalling events underlying short-term memory formation.