# Excitatory and Inhibitory Mechanisms of Divisive Normalization in Mouse V1

> **NIH NIH F30** · UNIVERSITY OF CHICAGO · 2021 · $51,036

## Abstract

Project Summary
 This project aims to elucidate the dynamics, population correlation changes, and cell types involved in
divisive normalization in mouse V1. Divisive normalization is a canonical nonlinear computation that allows for
multisensory integration, and that is carried out by populations of neurons. In the computation, the response of
one neuron to a given stimulus is a weighted average of its response to all stimuli shown – not just its preferred
stimulus. Divisive normalization underlies sensory modalities as diverse as olfactory integration in fruit flies and
photoreceptor adaptation from light to dark environments, as well as higher-order cognitive functions like
decision-making in monkey parietal cortex and changes in neural correlates of attention in monkey. When
central brain computations go awry, the consequences can be severe – and divisive normalization has been
implicated in brain disorders like autism. While divisive normalization is a ubiquitous and potentially clinically
relevant brain computation, its functional circuitry, and even the cell types involved in the computation, remain
unknown. This project aims to address that gap in understanding. To complete this project, I will investigate
divisive normalization in mouse visual cortex. A mouse model will enable the use of powerful in vivo genetic,
electrophysiology, imaging, optogenetic, and psychophysics techniques. Here, I will use transgenic and viral
transfections to functionally label excitatory and inhibitory neurons in mouse V1. Through a surgically
implanted chronic window, I will use state-of-the-art two-photon imaging to capture the activity of V1 excitatory
and inhibitory neuron populations in awake, ambulating mice presented with stimuli that evoke divisive
normalization. Additionally, I will optogenetically manipulate inhibitory populations during divisive normalization.
To analyze my data, I will use advanced computational approaches to model circuit activity. These
experiments will further elucidate the functional population dynamics and cell type contributions involved in
divisive normalization. We anticipate this project will provide groundwork for continuing to study divisive
normalization in the mouse and may ultimately lead to circuit dissection and behavioral assays, contributing to
an understanding of the role of divisive normalization in normal physiology and behavior, aberrant circuitry, and
disease.

## Key facts

- **NIH application ID:** 10186463
- **Project number:** 5F30EY030733-02
- **Recipient organization:** UNIVERSITY OF CHICAGO
- **Principal Investigator:** Zaina Adel Zayyad
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $51,036
- **Award type:** 5
- **Project period:** 2020-06-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10186463

## Citation

> US National Institutes of Health, RePORTER application 10186463, Excitatory and Inhibitory Mechanisms of Divisive Normalization in Mouse V1 (5F30EY030733-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10186463. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*