Mechanisms of Sensory Discrimination: Insights from Drosophila Olfaction.

All an animal can do to infer the state of its environment is to observe the sensory-evoked activity of its own neurons. These inferences about the presence, quality, or similarity of objects are probabilistic and inform behavioral decisions that are often made in close to real time. Neural systems employ several strategies to facilitate sensory discrimination: Biophysical mechanisms separate the neuronal response distributions in coding space, compress their variances, and combine information from sequential observations. We review how these strategies are implemented in the olfactory system of the fruit fly. The emerging principles of odor discrimination likely apply to other neural circuits of similar architecture. Expected final online publication date for the Annual Review of Biophysics Volume 48 is May 3, 2019. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.