A Seoul National University team on Wednesday said it has identified the cause of brain cell degeneration in diseases such as dementia or Alzheimer's.

Led by professor Kang Bong-kyun, the team said that when neurons are influenced by toxic materials like noxious oxygen, the protein copelin begins to excessively activate.

The protein affects synapse, a small gap separating neurons, and eventually causes actin, a globular protein in the synapse, stick together.

Kang said finding a method to control copelin will make a significant contribution to developing new medicine to block the progress of degenerative diseases.