Surround Integration Organizes a Spatial Map during Active Sensation

Neuron. 2017 Jun 21;94(6):1220-1233.e5. doi: 10.1016/j.neuron.2017.04.026. Epub 2017 May 11.


During active sensation, sensors scan space in order to generate a representation of the outside world. However, since spatial coding in sensory systems is typically addressed by measuring receptive fields in a fixed, sensor-based coordinate frame, the cortical representation of scanned space is poorly understood. To address this question, we probed spatial coding in the rodent whisker system using a combination of two-photon imaging and electrophysiology during active touch. We found that surround whiskers powerfully transform the cortical representation of scanned space. On the single-neuron level, surround input profoundly alters response amplitude and modulates spatial preference in the cortex. On the population level, surround input organizes the spatial preference of neurons into a continuous map of the space swept out by the whiskers. These data demonstrate how spatial summation over a moving sensor array is critical to generating population codes of sensory space.

Keywords: active sensation; barrel cortex; calcium imaging; electrophysiology; receptive field; sensory map; thalamus; whisker.

MeSH terms

  • Animals
  • Calcium / metabolism
  • Electrophysiological Phenomena
  • Mice
  • Neurons / metabolism
  • Neurons / physiology*
  • Optical Imaging
  • Physical Stimulation
  • Somatosensory Cortex / cytology
  • Somatosensory Cortex / metabolism
  • Somatosensory Cortex / physiology*
  • Spatial Processing / physiology*
  • Thalamus / metabolism
  • Thalamus / physiology*
  • Touch / physiology*
  • Vibrissae*


  • Calcium