TUESDAY, May 8, 2007 (HealthDay News) -- A certain form of a protein called neuropsin, which plays a role in learning and memory, is expressed only in the central nervous system of humans, concludes a Chinese study that compared the DNA of humans to several species of monkeys and apes.
The finding gives valuable insight into the evolution of the human brain, says a team from the Chinese Academy of Sciences, Kunming.
The study also found that type II neuropsin found in humans originated about five million years ago. Type II neuropsin is a longer form of the protein.
The findings, which contribute to the understanding of human cognition, are expected to be published online in the journal Human Mutation.
The researchers said that a mutation specific to humans triggers a change in the splicing pattern of the neuropsin gene, creating a new splicing site and a longer protein. When the scientists introduced this mutation into chimpanzees, they started to produce type II neuropsin.
"Hence, the human-specific mutation is not only necessary but also sufficient in creating the novel splice form," the study authors wrote.
"The present results underscore the potential importance of the creation of novel splicing forms in the central nervous system in the emergence of human cognition," they concluded.
There's much more on the human brain at Harvard University.