Universities of Bonn and Mainz researchers have discovered a novel mechanism that protects the brain from degeneration, repair, aging process. They found a hitherto unknown function of the cannabinoid-1 receptor (CB1).
In experiments with mice, they switched off CB1. As a consequence, the animals showed signs of degeneration - as seen in people with dementia - much faster.
"This means that the CB1 signal system has a protective effect for nerve cells," said Onder Albayram, principal author of the publication and a doctoral student on the team of Professor Dr. Andreas Zimmer from the Institut fur Molekulare Psychiatrie at the University of Bonn.
The researchers studied mice in different age categories - young six-week-old animals, middle-aged ones at five months, and those of an advanced age at 12 months.
The animals had to master various tasks - first, they had to find a submerged platform in the pool. Once the mice knew its location, the platform was moved, and the animals had to find it again. This was how the researchers tested how well the rodents learned and remembered.
The animals in which the CB1 receptor had been switched off (the knock-out mice) clearly differed from their kind.
"The knock-out mice showed clearly diminished learning and memory capacity," said Privatdozent Dr. Andras Bilkei-Gorzo from Professor Zimmer's team, who led the study.
"In addition, they showed a clear loss of nerve cells in the hippocampus," he said.
This part of the brain is the central area for forming and storing information. In addition, the researchers found inflammation processes in the brain. As the mice advanced in age, the degenerative processes became increasingly noticeable.
The animals with the intact CB1 receptor, to the contrary, did clearly better with regard to their learning and memory capabilities, as well as the health of their nerve cells.