A new study suggests that a slight modification in a crucial brain molecule might help explain how Alzheimer’s disease progresses from abnormal connections between nerve cells into a disease that impairs memory. This research was conducted at South Korea’s Institute for Basic Science.
According to previous research, abnormal protein clusters in the brain, known as amyloid plaques and tau tangles, are counted among the major causes of Alzheimer’s disease. These protein clusters are actually a symptom of a broader disorder during which the brain’s nerve cells become excessively active, begin losing their connections with one another, and their supporting cells also become abnormally active. However, how all these changes ultimately cause a decline in memory and thinking ability remains one of the biggest mysteries of Alzheimer’s.
According to new research from South Korea’s Institute for Basic Science, a receptor protein molecule called ErbB4 might be the key missing link to this puzzle. The study revealed that the abnormal activity of the ErbB4 receptor in a type of nerve cell (known as excitatory neurons) can simultaneously trigger several problems associated with Alzheimer’s.
Researchers observed that a specific type of excitatory neurons appears early in the Alzheimer’s process, and these cells contain the ErbB4 receptor, which helps nerve cells respond to external signals. During the study, scientists first examined two main types of brain cells (astrocytes and microglia), which support neurons and play a critical role in clearing out unnecessary or damaged neural connections. Scientists have long suspected that this natural cleaning system of astrocytes and microglia is impaired in Alzheimer’s. Researchers found that in mice with Alzheimer’s-like symptoms, astrocytes and microglia began eliminating an increasing number of connections between healthy excitatory neurons. This implies that the problem may not solely be that brain cell connections weaken in Alzheimer’s, but rather that the brain’s own defense and cleaning system mistakenly destroys healthy neural connections, with ErbB4 potentially playing a key role in this process.
