# Role of neuronal ensembles in visual processing

> **NIH NIH F32** · COLUMBIA UNIV NEW YORK MORNINGSIDE · 2020 · $69,306

## Abstract

Project Summary
 Vision is the sensory modality that humans depend on most to navigate through the
world and to establish meaningful social relationships. Disorders of the visual system therefore
often lead to severe interpersonal and economic hardships. Although much progress has been
made dissecting the retinal mechanisms that generate action potentials in response to light,
surprisingly little is known about how the brain actually interprets and contextualizes these
signals. I propose to leverage cutting-edge optical technologies to clarify how neuronal
ensembles (coactive groups of cells) encode sensory information in primary visual cortex (V1),
the neocortical region which is required to perform cognitively demanding tasks including visual
discrimination. Ensembles in V1 exhibit activity patterns with reproducible spatial and temporal
structures which define the functional vocabulary of cortical microcircuits and that likely carry
information pertaining to both the visual field and to the internal state of the animal. Yet how
these computations emerge, whether they are comprised of independent circuits, and the extent
to which they provide a template for visual perception remain unknown. To address these
questions, I will perform chronic two-photon holographic calcium imaging of a consistent
population of V1 neurons in awake mice learning a visually-guided task. Imaging the same
region longitudinally will allow us to identify how cortical ensembles emerge or are remodeled as
visual features become task-salient (Aim 1). Then, to test their functional role, I will artificially
activate identified neural ensembles with two-photon holographic optogenetics to test whether
their activity is sufficient to generate a percept and to elicit the expected visually-evoked
response (Aim 2). Successful completion of these experiments will test whether neural
ensembles are indeed building blocks of cortical function and will provide a new understanding
of the link between perception and behavior. Furthermore, the current project will demonstrate
how cortical ensembles integrate visual information with non-sensory variables during learning
and will yield new inroads towards a more complete understanding of vision, a prerequisite to
addressing the paucity of effective treatments options for illnesses such as blindness.

## Key facts

- **NIH application ID:** 9889805
- **Project number:** 5F32EY029161-02
- **Recipient organization:** COLUMBIA UNIV NEW YORK MORNINGSIDE
- **Principal Investigator:** Alejandro Akrouh
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $69,306
- **Award type:** 5
- **Project period:** 2019-08-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9889805

## Citation

> US National Institutes of Health, RePORTER application 9889805, Role of neuronal ensembles in visual processing (5F32EY029161-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9889805. Licensed CC0.

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