Janelia researchers have found a new way to watch how brain connections change during learning. Neurons, the brain’s cells, send fast signals through tiny gaps called synapses. Experiences tweak these connections’ strength, a process called synaptic plasticity. This process drives learning and memory.
Scientists don’t fully know where in the brain these shifts happen. The new method, DELTA, shows these changes across the whole brain.
DELTA tracks synaptic proteins, which help synapses change. Proteins break down or grow as connections shift. Following these protein changes during learning helps scientists spot active brain areas. This points them to key spots for learning and memory. It also reveals how molecules drive these shifts. The researchers say older methods couldn’t pinpoint where changes occur. DELTA uses imaging to zoom into tiny brain structures, linking behavior to brain mechanics.
The researchers have described the methods and results of this study in a paper published in Nature Neuroscience.
How DELTA reveals brain shifts
The method starts by tagging a synaptic protein in a mouse brain with a bright dye, Janelia Fluor. Researchers trained mice to link visual cues with water rewards. After tagging, they split the mice into two groups. One group got random water at both cues, like before. The other group learned only one cue meant water. Days later, after seeing behavior differences, they tagged the same protein with another dye. Some old proteins broke down, and new ones grew with the second dye. Imaging the brain showed where protein changes happened, hinting at learning spots.
The study found that learning the new task changed the protein GluA2 in specific brain areas. Researchers also tested mice in normal versus toy-filled environments. The enriched setup sparked GluA2 changes brain-wide. DELTA gives scientists a map to study learning’s cellular and molecular roots. Next, they aim to track when proteins shift during learning days.