# Spatial segregation of piriform output neurons toward cognitive and emotional networks

**Authors:** Chien-Fu F Chen, Donald A Wilson

PMC · DOI: 10.1093/pnasnexus/pgag026 · PNAS Nexus · 2026-02-12

## TL;DR

The piriform cortex organizes its output neurons spatially to connect with brain regions involved in emotion and cognition, suggesting specialized odor processing.

## Contribution

This study reveals spatially segregated output neuron populations in the piriform cortex projecting to distinct brain regions.

## Key findings

- PCx output neurons projecting to BLA and LO show distinct spatial distributions.
- These findings suggest functional specialization in odor encoding and behavior.

## Abstract

The piriform cortex (PCx), commonly considered to be the primary olfactory sensory cortex, differs from other mammalian sensory cortices by not displaying a stimulus-specific spatial organization but rather displaying widely distributed odor-evoked activity. However, there is evidence of a PCx spatial organization based on output neuron targeting. Here, we performed double-labeled retrograde tracing to reveal neuronal populations of PCx output neurons that project to two regions affiliated with different behavioral significance, the basolateral amygdala (BLA) and lateral orbitofrontal (LO) cortex networks. We found that PCx neurons projecting to BLA and LO are distinct in spatial distribution with minimal overlap, supporting the hypothesis that while odor input is distributed randomly across the PCx, PCx output neurons are organized into target-specific neuronal populations that potentially serve as functional units for odor encoding and odor-guided behavior.

## Full-text entities

- **Genes:** Pcyt1b (phosphate cytidylyltransferase 1B, choline) [NCBI Gene 286936] {aka CCT-beta, CTB, Cctbeta}
- **Chemicals:** Alexa Fluor 488 (MESH:C000711379), Alexa Fuor 488 (-), paraformaldehyde (MESH:C003043), sucrose (MESH:D013395), Xylazine (MESH:D014991)
- **Species:** Rattus norvegicus (brown rat, species) [taxon 10116], Homo sapiens (human, species) [taxon 9606], Drosophila melanogaster (fruit fly, species) [taxon 7227]

## Full text

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## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12917545/full.md

## References

73 references — full list in the complete paper: https://tomesphere.com/paper/PMC12917545/full.md

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Source: https://tomesphere.com/paper/PMC12917545