Evidence accumulating over the past 15 years refutes the dogma that the Drosophila nervous system is hardwired. The preponderance of studies reveals activity-dependent neural circuit refinement driving the optimization of behavioral outputs. Here, we describe developmental, sensory input-dependent plasticity in the brain olfactory antennal lobe that we term long-term central adaption (LTCA). LTCA is evoked by prolonged exposure to an odorant during the first week of post-eclosion life, resulting in a persistent decreased response to aversive odors and enhanced response to attractive odors. This limited window of early-use, experience-dependent plasticity represents a critical period of olfactory circuit refinement tuned by initial sensory input. Consequent behavioral modifications have been associated with changes in the output of olfactory projection neurons to higher brain centers. Recent studies have indicated a central role for local interneuron signaling in LTCA presentation. Genetic and molecular analyses have implicated RNA-binding Fragile X Mental Retardation Protein (FMRP) and Ataxin-2, Notch trans-synaptic signaling and cAMP signal transduction as key regulatory steps in LTCA. In this article, we discuss the structural, functional and behavioral changes associated with LTCA, and review our current understanding of the molecular pathways underlying these developmental, experience-dependent changes in the olfactory circuitry.
- Critical period
- Fragile X Mental Retardation Protein
- Copyright © 2016, Journal of Neurophysiology