Divisive normalization in olfactory population codes.


Journal Article

In many regions of the visual system, the activity of a neuron is normalized by the activity of other neurons in the same region. Here we show that a similar normalization occurs during olfactory processing in the Drosophila antennal lobe. We exploit the orderly anatomy of this circuit to independently manipulate feedforward and lateral input to second-order projection neurons (PNs). Lateral inhibition increases the level of feedforward input needed to drive PNs to saturation, and this normalization scales with the total activity of the olfactory receptor neuron (ORN) population. Increasing total ORN activity also makes PN responses more transient. Strikingly, a model with just two variables (feedforward and total ORN activity) accurately predicts PN odor responses. Finally, we show that discrimination by a linear decoder is facilitated by two complementary transformations: the saturating transformation intrinsic to each processing channel boosts weak signals, while normalization helps equalize responses to different stimuli.

Full Text

Duke Authors

Cited Authors

  • Olsen, SR; Bhandawat, V; Wilson, RI

Published Date

  • April 2010

Published In

Volume / Issue

  • 66 / 2

Start / End Page

  • 287 - 299

PubMed ID

  • 20435004

Pubmed Central ID

  • 20435004

Electronic International Standard Serial Number (EISSN)

  • 1097-4199

International Standard Serial Number (ISSN)

  • 0896-6273

Digital Object Identifier (DOI)

  • 10.1016/j.neuron.2010.04.009


  • eng