Hebrew University Researcher Uses Transparent Zebrafish to Decode Brain and Social Behavior

Professor Lilach Avitan, a neuroscientist at the Edmond and Lily Safra Center for Brain Sciences at the Hebrew University of Jerusalem, studies how natural behavior emerges from brain activity. Her research focuses on the zebrafish, a small transparent vertebrate whose entire brain activity can be observed at the cellular level during behavior. This unique feature allows scientists to track how information is processed across the brain in real time.

Avitan explains that despite the vast differences between human and zebrafish brains, fundamental neural principles are shared. Zebrafish exhibit complex social behaviors such as recognizing others, protecting each other from predators, and showing empathy, challenging previous assumptions that social behavior requires a highly developed cortex. Her lab identified specific neurons in the zebrafish brain that drive social motivation; silencing just 40 cells eliminated the fish’s desire to approach others.

The team is now investigating whether activating these neurons can restore social behavior, particularly in zebrafish models with autism-related genetic mutations. They aim to understand if social deficits stem from disrupted neural patterns and whether targeted interventions can reverse them.

Avitan also studies how environmental factors like water temperature affect zebrafish hunting behavior. Remarkably, zebrafish maintain precise predatory actions even under nonoptimal temperatures by adjusting the timing between brain processes and body movements.

Her path to this research began during a postdoctoral fellowship in Australia, where advances in genetic labeling allowed direct visualization of neural activity. Each project takes about five years, involving experimental design, data collection, and complex analysis of activity from approximately 100,000 neurons. Avitan’s background in computer science and statistics is crucial for interpreting this vast data.

While she acknowledges that fully solving the brain’s mysteries may take decades, she finds excitement in each new discovery. Given a million-dollar grant, she would invest in new technologies and recruit talented researchers to advance their understanding of brain function and social behavior.