Researchers reporting online on July 26 in Current Biology, a Cell Press publication, have for the first time shown that they can control the behavior of monkeys by using pulses of blue light to very specifically
activate1 particular brain cells. The findings represent a key advance for
optogenetics(光遗传学) , a state-of-the-art method for making causal connections between brain activity and behavior. Based on the discovery, the researchers say that similar light-based mind control could likely also be made to work in humans for
therapeutic2 ends. "We are the first to show that optogenetics can alter the behavior of monkeys," says Wim Vanduffel of Massachusetts General Hospital and KU Leuven Medical School. "This opens the door to use of optogenetics at a large scale in
primate3 research and to start developing optogenetic-based therapies for humans."
In optogenetics, neurons are made to respond to light through the insertion of light-sensitive
genes4 derived5 from particular microbial organisms. Earlier studies had primarily
validated6 this method for use in
invertebrates7(无脊椎动物) and
rodents8, with only a few studies showing that optogenetics can alter activity in monkey brains on a fine scale.
In the new study, the researchers focused on neurons that control particular eye movements. Using optogenetics together with
functional9 magnetic
resonance10 imaging (fMRI), they showed that they could use light to activate these neurons, generating brain activity and subtle changes in eye-movement behavior.
The researchers also found that optogenetic
stimulation11 of their focal brain region produced changes in the activity of specific
neural12 networks located at some distance from the primary site of light
activation13.
The findings not only pave the way for a much more
detailed14 understanding of how different parts of the brain control behavior, but they may also have important clinical applications in treating Parkinson's disease,
addiction15, depression, obsessive-compulsive
disorder16, and other neurological conditions.
"Several neurological
disorders17 can be attributed to the
malfunctioning18 of specific cell types in very specific brain regions," Vanduffel says. "As already suggested by one of the leading researchers in optogenetics, Karl Deisseroth from Stanford University, it is important to identify the
underlying19 neuronal circuits and the precise nature of the
aberrations20 that lead to the neurological disorders and potentially to manipulate those malfunctioning circuits with high precision to restore them. The beauty of optogenetics is that, unlike any other method, one can affect the activity of very specific cell types, leaving others untouched."