# Mechanisms and Biomarkers of Metal Olfactory Injury in Salmon

> **NIH NIH P42** · UNIVERSITY OF WASHINGTON · 2021 · $422,395

## Abstract

PROJECT SUMMARY 
Exposure to environmental concentrations of pesticides and metals can cause neurobehavioral changes that 
influence survival of Pacific salmon. These neurological impacts that arise from central and peripheral nervous 
system deficits, including inhibition of peripheral olfactory function, may block the ability to detect predators and 
prey, alter reproductive timing, and interfere with homing to natal streams. The fish peripheral olfactory system 
is highly vulnerable to the toxic effects of dissolved contaminants due to its direct contact with the aquatic 
environment. Olfactory injury is now documented in other aquatic species exposed to environmental pollutants, 
suggesting far-reaching ecological ramifications of this phenomenon. The goal of our project is to understand 
the mechanisms of chemical-induced olfactory injury in Pacific salmon, and based upon our findings, generate 
biomarkers of olfactory injury to evaluate the ecological health and remediation outcomes at Superfund sites. 
Our studies will also use zebrafish, a well-defined genetic model, to better understand the mechanisms of 
olfactory injury that are relevant to salmon. In the current application, we will continue to integrate molecular, 
biochemical, physiological, and behavioral endpoints using model metal olfactory toxicants that are relevant to 
Superfund exposures. This novel approach allows a thorough understanding of mechanisms of chemical- 
induced olfactory injury in fish. In Aim 1, we will use salmon and several transgenic zebrafish lines to identify 
olfactory receptor neuron populations that are targets of cadmium (Cd) and address impaired olfactory 
signaling and neuron regeneration (neurogenesis) as mechanisms of Cd-mediated olfactory injury. We will also 
use transgenic zebrafish to evaluate the potency of other Superfund metals as olfactory toxicants. In Aim 2, we 
will investigate transcriptional and post-transcriptional control of olfaction during metal exposures. We will 
identify functionally important olfactory microRNAs (miRNAs) and their gene targets that are essential 
regulators of metal-induced olfactory injury. In Aim 3, we will test glutathione S-transferase (GST) isoforms as 
biomarkers of olfactory injury, and investigate the mechanisms of Nrf2 in olfactory neuroprotection. We will 
then incorporate our most robust olfactory molecular biomarkers to evaluate remediation outcomes in the lower 
Duwamish waterway, a regional Superfund site at various stages of remediation. We have assembled a strong 
team of collaborators for this project whose interactions are described in the proposal. We have endeavored to 
be responsive to SRP objectives by using mechanistic approaches to address ecological and human health 
hazards, as well as remediation outcomes at Superfund sites. Our studies involve strong partnerships with WA 
State and federal agencies involved in Superfund site assessment, and with community stakeholders affected 
by ha...

## Key facts

- **NIH application ID:** 10137958
- **Project number:** 5P42ES004696-33
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** EVAN P GALLAGHER
- **Activity code:** P42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $422,395
- **Award type:** 5
- **Project period:** 1997-04-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10137958

## Citation

> US National Institutes of Health, RePORTER application 10137958, Mechanisms and Biomarkers of Metal Olfactory Injury in Salmon (5P42ES004696-33). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10137958. Licensed CC0.

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