# Circuit mechanisms underlying experience-dependent development

> **NIH NIH R01** · BRANDEIS UNIVERSITY · 2021 · $413,904

## Abstract

PROJECT SUMMARY:
Abnormal gene expression or abnormal sensory experience during development has a profound and
permanent impact on the construction of brain circuits. Many developmental diseases likely do not arise from a
single defect that is present in all sufferers, but rather from the systems-level impact of the interaction of any
number of malfunctioning circuit elements. In order to understand how the elements of brain circuits interact
during development and to shed light on how these processes go awry in diseases or injuries, it is important to
investigate whole systems in the intact, living brain. To this end, we have developed a system via which we can
study how individual mammalian cortical neurons change their properties when the circuit is modified by
behaviorally relevant stimuli.
 This application proposes studies of the circuit mechanisms underlying the experience-dependent
development of motion selectivity in the ferret visual cortex. At the time of eye opening, ferret visual cortex
exhibits orientation selectivity and orientation columns, but neurons are not yet selective for direction-of-
motion, a property of most mature neurons in this species. Motion selectivity (that is, direction selectivity)
arises in the days and weeks following eye opening, and requires visual experience. However, recent
experiments show that this experience has a primarily permissive influence on development, in that many
parameters such as direction preference angle and speed tuning are primarily determined before the onset of
visual experience.
 The first aim addresses the degree to which the activity in the cortex before eye opening determines the
tuning parameters that can be uncovered through visual experience. We will provide animals with artificial
experience with carefully designed “arbitrary” patterns to examine how tuning parameters can be modified.
Alternatively, the activity in cortex before eye opening may itself be permissive and activity-independent factors
may determine tuning parameters.
 The second aim tests a novel hypothesis about the development of functional connections in early
development. The classic idea is that connections are substantially overproduced and that experience and
plasticity serve to prune inappropriate connections. Instead, we will test the idea that receptive fields start out
small and grow in a manner that is largely determined at the onset of visual experience.
 The third aim directly examines the functional connections between LGN and cortex that might underlie
direction selectivity and its development.
 Concurrently with the aims, a computational model of the ferret visual cortex will be constructed to
illuminate the possible combinations of synaptic plasticity rules and initial circuit structure that could underlie
the development of direction selectivity and speed tuning.

## Key facts

- **NIH application ID:** 10136600
- **Project number:** 5R01EY022122-08
- **Recipient organization:** BRANDEIS UNIVERSITY
- **Principal Investigator:** STEPHEN D VAN HOOSER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $413,904
- **Award type:** 5
- **Project period:** 2013-06-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10136600

## Citation

> US National Institutes of Health, RePORTER application 10136600, Circuit mechanisms underlying experience-dependent development (5R01EY022122-08). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10136600. Licensed CC0.

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