# Local circuits in the olfactory bulb

> **NIH NIH R01** · CASE WESTERN RESERVE UNIVERSITY · 2021 · $342,125

## Abstract

Project Summary
A central question in neuroscience is how sensory stimuli in the environment are represented. The olfactory
system is an attractive sensory modality to approach this question since the major excitatory pathways that
connect receptor neurons, second-order mitral cells in the olfactory bulb, and tertiary neurons in olfactory
cortex and well understood. However, intracellular recordings demonstrate that neural representations of
odors in second-order neurons (mitral and tufted cells) do not result exclusively from feedforward input from
receptor cells. Instead, the output of the olfactory bulb results from complex interactions between excitatory
and inhibitory circuits. Relatively little is known about the neural circuits that generate inhibition onto
principal cells. The present proposal uses rodent brain slice recording methods to determine how local
circuit pathways excite GABAergic olfactory bulb interneurons, inhibiting and shaping firing patterns in
principal cells. Using both whole-cell intracellular recording and live 2-photon imaging methods, we will
determine how the key synaptic pathways that enable sensory input to excite granule cells function and how
they recruit intrinsic currents within granule cells. The proposal also will determine how inhibitory synaptic
input to granule cells functions to modulation action potential discharges. Finally, the proposed work also
will determine the functional role of a recently discovered form of long-term synaptic plasticity apparent in
one class of these inputs. Defining the cellular mechanisms that generate sensory-evoked inhibition in the
olfactory bulb, the overall focus of this proposal, is critical to understand how biological information is
represented in the brain. The proposed studies also are significant as they represent an important step
toward understanding the specific deficits in many major neurodegenerative diseases in which olfactory
function is affected. In many of these diseases, sensory impairments occur early in the disease onset.
Insights into the specific olfactory mechanisms affected in these diseases may lead to directly testable
hypotheses regarding analogous mechanisms in the cortical areas responsible for the cognitive deficits
commonly associated with neurodegenerative disorders.

## Key facts

- **NIH application ID:** 10188484
- **Project number:** 5R01DC004285-17
- **Recipient organization:** CASE WESTERN RESERVE UNIVERSITY
- **Principal Investigator:** Ben W Strowbridge
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $342,125
- **Award type:** 5
- **Project period:** 2000-08-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10188484

## Citation

> US National Institutes of Health, RePORTER application 10188484, Local circuits in the olfactory bulb (5R01DC004285-17). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10188484. Licensed CC0.

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