# Behavior-dependent neuromodulation of retinogeniculate axonal boutons

> **NIH NIH R21** · BETH ISRAEL DEACONESS MEDICAL CENTER · 2020 · $263,950

## Abstract

In mice, there are more than 30 different retinal ganglion cell types that encode the visual scene,
transmitting information about motion direction, orientation, location, size and luminance. These cell
types provide rich detail about the surrounding environment. However, during certain brain states and
behaviors, some channels of information are more important than others. For example, during
locomotion or foraging, visual processing of objects in front of you may be more important than
detection of certain visual cues, such as weak threat cues from looming predators. Recent studies in
the cortex and thalamus have identified synaptic and circuit mechanisms that heighten sensitivity to
specific relevant visual stimuli and/or suppress irrelevant information depending on brain state. In this
proposal, the Chen and Andermann laboratories propose to test a hypothesis that state-dependent
modulation of visual sensitivity begins at a much earlier station in the visual pathway, at the level of
the retinal ganglion cell terminals as they innervate the dorsal lateral nucleus (LGN), the visual
thalamus. Further, this sensitivity may be conferred by direct neuromodulatory actions of serotonin.
The Andermann lab will image visual responses from retinal axonal boutons of different retinal
ganglion cell types across states of quiet waking and arousal while manipulating serotonergic
signaling in LGN. The Chen lab will perform in vitro electrophysiology experiments to assess the
magnitude of presynaptic modulation by serotonin in distinct genetic classes of retinal inputs to LGN,
using two-color optogenetic activation of genetic subtypes of retinal axons, together with stimulation
of serotonergic axon terminals in LGN. If our hypotheses are confirmed, this synergistic collaboration
between the two labs will establish a conceptually novel framework for understanding behavioral
modulation of early visual processing and perception, and provide important insights into disorders of
cognition and visual perception.

## Key facts

- **NIH application ID:** 9919566
- **Project number:** 5R21EY030243-02
- **Recipient organization:** BETH ISRAEL DEACONESS MEDICAL CENTER
- **Principal Investigator:** Mark L Andermann
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $263,950
- **Award type:** 5
- **Project period:** 2019-05-01 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9919566

## Citation

> US National Institutes of Health, RePORTER application 9919566, Behavior-dependent neuromodulation of retinogeniculate axonal boutons (5R21EY030243-02). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/9919566. Licensed CC0.

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