# The assembly of population coding networks

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2024 · $382,626

## Abstract

PROJECT SUMMARY
Population coding is a fundamental strategy that the nervous system employs to represent sensory stimulus
and generate perception. In neural networks that perform population coding (termed “population coding
networks (PCNs)”), input-elicited responses are quantitatively heterogeneous across neurons and the
response of a single neuron does not sufficiently define the stimulus; instead, the computed response of the
entire population of neurons underlies the perception of the stimulus. Despite the importance of PCNs, very
little is known about how they are assembled during development. The objective of the proposed research
is to identify the mechanisms that establish a PCN during development. In many PCNs, the constituent
neurons are not distinguishable from each other, except by their heterogeneous physiological properties.
While the apparent homogeneity of these PCNs ensures that constituent neurons contribute to the same
brain function, it also poses a challenge for studying the molecular and cellular mechanisms that underlie
the assembly of PCNs. A recent study reported a neural network that encodes the intensity of noxious
inputs through population coding in Drosophila larvae, which offers an excellent system for studying PCN
assembly. Preliminary results suggest that Hox genes are involved in establishing this PCN. The central
hypothesis is that a post-mitotic Hox code specifies the synaptic inputs to different neurons along the A-P
axis, establishing a population-coding network that encodes stimulus intensity. This hypothesis will be
tested by identifying the cellular (Aim 1) and molecular (Aim 2) mechanisms that establish the heterogeneity
of the neurons in this PCN. The proposed research is innovative because it proposes novel cellular and
molecular mechanisms that generate quantitative heterogeneity in a neural network. Moreover, it will use a
newly developed technique that is ideally suited for studying neuronal population activity in the PCN. Novel
genetic tools have also been developed for accessing subpopulation of neurons in the PCN. This research
is significant because it will provide cellular, molecular, and conceptual insights into the establishment of
other PCNs in Drosophila and other species. Beyond the PCNs, it will inform how physiological
heterogeneity arises in a seemingly identical group of neurons. Furthermore, the successful completion of
the proposed study will also demonstrate a Hox-based matching system that establish neuronal
connections confined to specific rostrocaudal segments.

## Key facts

- **NIH application ID:** 10812429
- **Project number:** 5R01NS128500-02
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** BING YE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $382,626
- **Award type:** 5
- **Project period:** 2023-04-01 → 2028-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10812429

## Citation

> US National Institutes of Health, RePORTER application 10812429, The assembly of population coding networks (5R01NS128500-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10812429. Licensed CC0.

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