Alzheimer’s disease (AD), commonly known as senile dementia, is a degenerative disease of the nervous system, causing symptoms such as memory loss, aphasis, unresponsiveness, disorientation, mood and behavior changes in its patients. According to the data from World Health Organization, among the 50+ million people with dementia worldwide, 60%-70% are AD patients.
During the 3rd World Laureates Forum, CCTV News invited Su Guohui, Member of of the Chinese Academy of Sciences, to the live streaming room, and brought together Professor Peter Walter of the University of California San Francisco, Professor Randy Schekman University of California Berkeley, 2013 Nobel Laureate in Physiology or Medicine, and Chair Professor Thomas Südhof of Stanford University online to share the latest research results on Alzheimer’s disease.
Symptoms of forgetfulness and memory decline in young people are not necessarily a sign of AD
Professor Randy Schekman said that it is not necessarily only the elderly who get Alzheimer’s disease. From a genetic perspective, some people may develop the disease at an earlier age. A team in Sweden had done a good job in predicting the progression of AD through phosphorylated protein Tau markers. They found that the blood samples of some patients showed that the incubation period of the disease might be as long as 20 years. Although there are no symptoms, the disease always lurks in the body.
Professor Thomas Südhof explained the early symptoms of Alzheimer’s disease, and said that symptoms of forgetfulness and memory decline in young people are not necessarily a sign of Alzheimer’s disease.
He said that there is no need to worry too much about some memory loss in the early stage. Signs show that AD is a cognitive disease with a long course, and the symptoms do not show up until a certain stage. Memory loss in the early stage refers to “explicit memory” rather than “implicit memory”. AD only affects explicit memory. Only when the brain is severely damaged can implicit memory be affected.
Professor Südhof explained that explicit memory means the things that you can explain. For example, if someone asks you how to get to the train station, you can tell him (turn left or right, etc.). Implicit memory is automatic memory, and you don’t know how the process has happened. For example, when you mount on a bicycle, you can ride it naturally without the need to think whether you should move the left leg or the right leg first.
Prevention is more important than treatment
Several professors discussed treatment methods of AD, and compared them with the often-used methods to treat neurodegenerative diseases in the world. Currently, deep brain stimulation is a common method to treat Parkinson’s disease, and shows certain effects in the treatment of AD. Professor Randy Schekman said that deep brain stimulation is only palliative treatment, unable to prevent disease progression. The failure rate of drug development is 100%, which means that there is no drug that can slow down neurodegeneration.
Regarding the gene therapy proposed by some scientists, Professor Peter Walter said that gene therapy is to knock out dominant alleles, rather than increase so-called normal genes. Given the fact that the exact disease-causing gene hasn’t been found because of the complex cause of AD, he believed that gene therapy is unpromising.
In this case, prevention of AD is more important than treatment. Professor Su Guohui proposed that finding a way to protect neurons and delay the disease process offers a good disease management strategy.
Research on AD needs to be continued in the future
Professor Thomas Südhof said that some genes can prove that some people will suffer from AD someday, while others can explain why some people are less likely to develop the disease. These are his two research directions for now. He also said that people have gained much better understanding of the disease in the past five years, and hoped that more people will work together in scientific research in order to make greater progress in delaying disease progression.