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Updated: Apr 17, 2026
Author Spotlight: Using Zebrafish to Explore Microglia Migration During Brain Development
Published on: May 17, 2024
Domoic acid induces developmental stage-specific effects on microglia in zebrafish
Alia S Hidayat1, Jordan A Pitt2, Helen Fredricks3
1Biology Department and Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA; Massachusetts Institute of Technology (MIT) - Woods Hole Oceanographic Institution (WHOI) Joint Graduate Program in Oceanography and Oceanographic Engineering, USA; Center for American Progress, WA, DC 20002, USA.
Harmful algal blooms release domoic acid (DA), a neurotoxin affecting shellfish and humans. This study shows DA impacts developing zebrafish microglia, the brain's immune cells, in stage-specific ways, suggesting potential neuroinflammation risks.
Area of Science:
- Neuroscience
- Environmental Toxicology
- Developmental Biology
Background:
- Harmful algal blooms (HABs) produce domoic acid (DA), a neurotoxin contaminating seafood and causing amnesic shellfish poisoning.
- DA is known to affect neurons by binding to glutamate receptors, but its impact on non-neuronal brain cells like microglia is less understood.
- Microglia are crucial for brain health, and developmental disruptions can lead to long-term functional deficits and disease risk.
Purpose of the Study:
- To investigate the effects of developmental exposure to domoic acid (DA) on microglia in zebrafish (Danio rerio).
- To characterize DA's impact on microglial abundance, morphology, cell death, cytokine expression, and behavior at different developmental stages.
Main Methods:
- Zebrafish embryos and larvae were exposed to varying doses of DA at 2 and 4 days post-fertilization (dpf).
- Microglial abundance and morphology were assessed, alongside analyses of cell death, expression of inflammatory cytokines (il1b, il4, tgfb), and startle response behavior.
Main Results:
- DA exposure at 2 dpf increased microglial abundance and altered morphology, even at doses causing only transient tremors.
- At 4 dpf, the highest DA dose reduced microglial numbers and caused severe morphological defects.
- DA exposure at 4 dpf increased mRNA levels of il1b, il4, and tgfb, indicating inflammatory responses.
Conclusions:
- The effects of domoic acid on zebrafish microglia are highly dependent on the developmental stage of exposure.
- Microglial reactivity and potential neuroinflammation can occur at DA doses that do not cause overt morphological abnormalities.
- These findings highlight the need for further research into the subtle neurotoxic effects of low-dose DA exposure on brain immune cells during development.
