Researchers from the Medical Faculty of the University of Sao Paulo (FMUSP) believe they have identified the brain region that shows the first signs of Alzheimer’s disease. This region is critical as it could help to detect early Alzheimer’s disease in a patient.
Alzheimer’s disease begins in the brainstem, specifically in a region called the dorsal raphe nucleus, not in the cortex (the center of processing information and memory storage), such as medicine traditionally think. This idea is supported by Brazilian scientists, in partnership with German colleagues, in a forthcoming article in the scientific journal “Neuropathology and Applied Neurobiology“.
The study is based on brain autopsies of 118 people who had an average age of 75 years at the time of death. The researchers found that lesions of dorsal raphe nucleus in 8 deceased persons who did no other damage in the rest of the brain. These lesions of dorsal raphe nucleus were also detected among 80 people who already had at least a sign of degeneration in the cortex transentorhinal, the region traditionally known as the first to be affected by Alzheimer’s disease. The 88 individuals who had the anatomical features associated with cerebrovascular disease showed clinical manifestations of the disease to varying degrees, and some are even asymptomatic. This study was subject to many sources of Funding, in particular the CNPq and FAPESP.
The brain stem connects the cortex to the spinal cord, and, more rigorously, is not part of the brain but the brain (including brain, cerebellum and stem). The brainstem is an important component of the nervous system. It controls involuntary functions essential for survival, like breathing, cardiac motion, blood pressure, sleep and dreams.
If the results obtained by Brazilian researchers are confirmed by further studies, the fact that Alzheimer’s is initiated in the brainstem, and then propagates in regions interconnected with the cortex, is a crucial in the search for therapies that aim to curb the development of the disease in its initial stages.