Drug meant to help may cause memory impairment

We don’t hear a lot about side effects with drugs that treat dementia but many do have potentially adverse side effects. Some drugs could even causing dementia like symptoms. It is a sad irony that the drugs themselves could be impairing memory.

“Let’s proceed with caution,” said Robert Vassar, professor of cell and molecular biology at Northwestern University Feinberg School of Medicine. “We have to keep our eyes open for potential side effects of these drugs.”

The drugs causing concern are those that were designed to inhibit BACE1. This is the enzyme that promotes the development of the clumps of plaque denoting Alzheimer’s disease. BACE1 releases the proteins that cause the plaque buildup. A drug that blocks the enzyme might slow the progress of Alzheimer’s.

But Vassar’s new study shows this is wrong. BACE1 also plays an important role as the brain’s “electrician”. The enzyme maps out axons, the connections between neurons and the brain and the rest of the nervous system. When Vassar looked at mice whose BACE1 had been removed, their olfactory system no longer operated properly. These findings indicate the key role of BACE1 in the interconnectedness of all neurons.

“It’s like a badly wired house,” Vassar explained. “If the electrician doesn’t get the wiring pattern correct, your lights won’t turn on and the outlets won’t work.”

The hippocampus too could be vulnerable. Here, neurons are continually reborn. They must grow new axons to connect them with the existing system. Being part of that network relies on BACE1.

“It’s not all bad news,” Vassar speculated. “These BACE1 blockers might be useful at a specific dose that will reduce the amyloid plaques but not high enough to interfere with the wiring.”

Source: MedicalNewsToday, Molecular Neurodegeneration