Pulsed light therapy improves learning speed in aged rats
In a five-day learning protocol involving 14 aged male rats, 40-hertz pulsed light improved learning speed compared with no light stimulation.
Limit: Only 14 aged rats were included in the learning experiment
Edited by Boris Djordjevic · AgingResearch.News
In an animal experiment, researchers studied 21 male four-month-old Wistar rats and 14 male 18-month-old Wistar rats. They applied pulsed near-infrared light over the front of the head, delivering 33 joules per square centimeter with 720 seconds of effective exposure. Young rats received pulses at either 5 or 40 hertz; aged rats received 40 hertz. The learning protocol lasted five days.
Both frequencies enhanced cognitive flexibility—the ability to adapt to a changed task—in young rats. In aged rats, 40-hertz light improved learning speed. Brain analyses in aged rats found reduced Iba-1, a marker of immune cells called microglia, in the prefrontal cortex and hippocampus, a brain region involved in memory. The stimulation also increased NeuN, a marker of nerve cells, in the prefrontal cortex, at the front of the brain.
Why it matters
The aged-rat experiment addressed whether light stimulation could help with age-related learning decline. The authors see the results as supporting a targeted approach to improving cognitive function across the lifespan.
Caveats
This small animal experiment cannot establish benefits in people. It included only male rats, and the supplied results do not address whether the learning benefits persisted.
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The paper
Universidad Nebrija; Universidad de Oviedo
GeroScience, May 4, 2026, Open access
