Synaptic wiring motifs in posterior parietal cortex support decision-making

Nature. 2024 Mar;627(8003):367-373. doi: 10.1038/s41586-024-07088-7. Epub 2024 Feb 21.

Abstract

The posterior parietal cortex exhibits choice-selective activity during perceptual decision-making tasks1-10. However, it is not known how this selective activity arises from the underlying synaptic connectivity. Here we combined virtual-reality behaviour, two-photon calcium imaging, high-throughput electron microscopy and circuit modelling to analyse how synaptic connectivity between neurons in the posterior parietal cortex relates to their selective activity. We found that excitatory pyramidal neurons preferentially target inhibitory interneurons with the same selectivity. In turn, inhibitory interneurons preferentially target pyramidal neurons with opposite selectivity, forming an opponent inhibition motif. This motif was present even between neurons with activity peaks in different task epochs. We developed neural-circuit models of the computations performed by these motifs, and found that opponent inhibition between neural populations with opposite selectivity amplifies selective inputs, thereby improving the encoding of trial-type information. The models also predict that opponent inhibition between neurons with activity peaks in different task epochs contributes to creating choice-specific sequential activity. These results provide evidence for how synaptic connectivity in cortical circuits supports a learned decision-making task.

MeSH terms

  • Calcium / analysis
  • Calcium / metabolism
  • Decision Making* / physiology
  • Interneurons / metabolism
  • Interneurons / ultrastructure
  • Learning / physiology
  • Microscopy, Electron
  • Models, Neurological
  • Neural Inhibition
  • Neural Pathways* / physiology
  • Neural Pathways* / ultrastructure
  • Parietal Lobe* / cytology
  • Parietal Lobe* / physiology
  • Parietal Lobe* / ultrastructure
  • Pyramidal Cells / metabolism
  • Pyramidal Cells / ultrastructure
  • Synapses* / metabolism
  • Synapses* / ultrastructure
  • Virtual Reality

Substances

  • Calcium