Innovative Fish Models Reveal Strategies to Study Working Memory

For over thirty years, zebrafish have been a cornerstone of preclinical biomedical research, allowing scientists to study hundreds of individuals simultaneously and record whole-brain activity in living animals. However, their social nature poses limitations: as schooling fish, their behavior is significantly shaped by social interactions, which can influence experimental results when studied in isolation.

To address this challenge, researchers from Eötvös Loránd University (ELTE) and HUN-REN IEM turned to a more solitary, territorial fish species—the paradise fish. This species exhibits unique behaviors, making it an excellent complementary model for cognitive studies.

Comparative studies between zebrafish and paradise fish uncovered notable differences. Zebrafish tend to explore new environments more readily when in groups, benefiting from social cues. Conversely, paradise fish demonstrate a high degree of independence, effectively investigating unfamiliar spaces even alone, and sometimes outperforming zebrafish.

The research, published in Communications Biology, highlights a fascinating discovery: paradise fish utilize a behavior called "alternation," consistently swimming towards unexplored areas. This indicates a form of working memory—a cognitive process previously thought to be primarily mammals—and demonstrates a strategic approach to navigation.

Zoltán K. Varga, the study’s lead author and postdoctoral neuroscientist at HUN-REN IEM, emphasizes that their findings show different species adopt distinct strategies in similar tasks, which can be linked to their social and territorial behaviors. The combination of zebrafish and paradise fish offers a balanced, comprehensive platform for studying various aspects of brain function, including social interaction, problem-solving, and memory.

While zebrafish remain valuable for examining social behaviors, paradise fish can provide critical insights into solitary problem-solving and memory mechanisms. Notably, paradise fish have been studied extensively in the past at ELTE's Department of Ethology, and modern neuroscience continues to uncover their potential.

This research deepens our understanding of species-specific cognitive strategies, offering valuable tools for neuroscience and pharmacological research. Recognizing these natural differences enhances our ability to develop targeted interventions and understand complex brain functions.

Source: https://medicalx.press.com/news/2025-08-fish-species-strategies-memory.html