# Understanding signal processing in retinal bipolar cell pathways

> **NIH NIH R01** · UNIVERSITY OF LOUISVILLE · 2020 · $374,618

## Abstract

We have developed a powerful mouse model to study information processing in parallel retinal bipolar cell
pathways. Bipolar cells are essential for transmitting the photoreceptor output to the ganglion cells, which
signal visual information to a range of target areas in the brain. Bipolar cells divide into about a dozen types
and constitute the first level of information processing in the visual system. While several aspects of bipolar
cell function have been addressed in retinal slice preparations of a variety of species, information about
three fundamental aspects of bipolar cell signaling is still lacking. First is a concise, quantitative description
of the spatio-temporal receptive field for any genetically identified bipolar cell type. Second is a
comprehensive account of the neural mechanisms that govern the input-output transfer function of each BC
type, based on light-evoked responses with intact circuitry (whole-mount retina preparation). Third is the
impact of light-adaptive mechanisms on bipolar cell visual function.
We will leverage our recently developed live-cell imaging and whole-cell recording methods to
address these issues. Specifically, we will make targeted electrophysiological recordings in the whole-mount retina of transgenic mice with genetically identified bipolar cells; we will use two-photon fluorescence
imaging with genetically encoded fluorescent biosensors for calcium and glutamate in transgenic mice with
loss-of function mutations in the OFF bipolar pathways; and we will use advanced visual stimulation
methods to elucidate mechanisms of light-adaptation at the bipolar cell level. These studies will provide
valuable information about how bipolar cells encode visual information, and how visual sensitivity is
maintained under varying stimulus conditions. Understanding information processing in identified retinal
signaling pathways is critical for the study and potential treatment of developmental and neurological
disorders, and retinal disease.

## Key facts

- **NIH application ID:** 9959412
- **Project number:** 5R01EY028188-04
- **Recipient organization:** UNIVERSITY OF LOUISVILLE
- **Principal Investigator:** Bart Gerard Borghuis
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $374,618
- **Award type:** 5
- **Project period:** 2017-09-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9959412

## Citation

> US National Institutes of Health, RePORTER application 9959412, Understanding signal processing in retinal bipolar cell pathways (5R01EY028188-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9959412. Licensed CC0.

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