A new study by brain scientists at Brown University provides evidence that learning engages a brain process called long-term potentiation (LTP), which in turn strengthens synapses in the cerebral cortex.
The study provides the strongest evidence to date to support the 25-year-old hypothesis, generally accepted by neuroscientists, that learning uses LTP to produce changes in the connections (synapses) between brain cells (neurons) that are necessary to acquire and store new information, said lead author Mengia-Seraina Rioult-Pedotti.
Neuroscientists also theorize that higher forms of learning occur in the cerebral cortex. Evidence from the study supports that theory.
In the study, published in the Oct. 20 issue of Science, Brown University researchers taught rats to reach into a hole in a box to grasp food pellets, a new motor skill for the animals. After five days, the rats were tested.
The researchers found that not only had the animals behavior changed, through the learning of a new skill, but that their brains had also changed. Associated with that learning, the strength of synaptic connections between neurons in the motor cortex had increased through a process consistent with the use of LTP.
Importantly, the overall range of synaptic modification the maximum possible increase or decrease in strength had not changed, said Rioult-Pedotti, a neuroscience investigator. Using this synaptic modification range as a reference allowed our group to eliminate a weakness of earlier work, she said.
In previous studies, the researchers showed that synapses were modifiable through the LTP
process when those synapses were activated artificially by electrical impulses. However, it was
Contact: Scott Turner