Receptor successfully isolated to tackle Alzheimer’s

Scientists have discovered that blocking a specific part of an ion channel can prevent the memory loss associated with Alzheimer’s.

Nicotinic acetylcholine receptors (nAChRs) can be found in the cell membranes of the central and peripheral nervous system, and are involved in functions such as controlling voluntary movement, memory, pain and anxiety.

Researchers from the Institut Pasteur studied the ?2 subunit of nAChRs and, using mouse models, they discovered that when blocked, mice were protected from the memory loss associated with Alzheimer’s.

Uwe Maskos, main author of the study from Institut Pasteur, said: “Characterising this new therapeutic target will enable us to test molecules that are capable of blocking the ?2 subunit. The aim is to find a therapeutic molecule that resembles nicotine but does not have the same harmful effects such as dependence, premature cell aging, increased heart rate and effects on the gastroenteric system.”

Alzheimer’s disease is diagnosed by amyloid plaques and the build-up of coarse fibres within nerve cells in the brain. Amyloid plaques are formed by large concentrations of amyloid beta peptide which lead to a loss of neuronal structures and neurofibrillary degeneration which leads to nerve cells’ death.

Nine genes code for nicotinic receptors subunits in the hippocampus. Researchers created a mouse model where the ?2 subunit was inactivated by blocking the gene coding for it. Memory tests in these mice showed they did not develop and negative cognitive effects associated with Alzheimer’s. They also were protected from the effects of amyloid beta peptide.

Maskos said that no adverse effects on hippocampal function had been seen by blocking the ?2 subunit. However subunit ?7, when blocked, was found to negatively affect this function.

The results of this study were published in Neurobiology of Aging.