# Excitation and Inhibition in Neural Circuits of the Visual Cortex

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA BERKELEY · 2024 · $600,397

## Abstract

Project Summary
Neural circuits of the primary visual cortex (V1) are critical for generating perceptions of our external world. In
V1, most neurons exhibit potent modulation by stimuli that are outside their receptive fields, a process termed
`surround modulation'. Importantly, the magnitude and sign of surround modulation depend on the orientation
of the center and surround – leading to the notion that flexible surround modulation contributes to scene
segmentation, salience detection, contour integration, and figure/ground segregation. The specific neural
circuits in the visual cortex that explain the orientation dependence of surround modulation are largely
unknown. By combining two photon calcium imaging, two photon holographic optogenetics, in vivo patch clamp
electrophysiology, and the first use of a two photon holographic mesoscope, we aim to reveal the precise
synaptic and circuit architecture in the mouse visual cortex that mediates the earliest stages of image
segmentation. First, we will measure the visually evoked synaptic conductances in cortical interneurons that
explain their highly differentiated tuning properties to contextual visual stimuli. Next, we will precisely map the
local and long-rate connectivity onto specific subtypes of cortical interneurons in vivo using two photon photo-
stimulation. Finally, we will probe how two photon holographic co-activation of surround co-tuned ensembles in
V1 or higher visual areas give rise to figure/ground modulation in V1 principal neurons. Together, our aims will
establish a highly detailed mechanistic understanding for a visual computation responsible for object
recognition.

## Key facts

- **NIH application ID:** 10803639
- **Project number:** 2R01EY023756-11
- **Recipient organization:** UNIVERSITY OF CALIFORNIA BERKELEY
- **Principal Investigator:** Hillel Adesnik
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $600,397
- **Award type:** 2
- **Project period:** 2013-09-01 → 2029-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10803639

## Citation

> US National Institutes of Health, RePORTER application 10803639, Excitation and Inhibition in Neural Circuits of the Visual Cortex (2R01EY023756-11). Retrieved via AI Analytics 2026-09-03 from https://api.ai-analytics.org/grant/nih/10803639. Licensed CC0.

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