Memory loss is not just a nice plot twist in old-fashioned soap operas. It is a real problem that many people face after devastating injuries or simply because of advancing age. There are no very effective ways to fight memory loss. But now scientists conducted a study, which shows that by increasing a crucial cholesterol-binding membrane protein in nerve cells (neurons) within the brain it is possible to improve learning and memory in aged mice. These results may help creating new therapies for patients suffering from memory loss.
This study is a result of collaboration between several different science institutions. The Scripps Research Institute (TSRI), the Veterans Affairs San Diego Healthcare System (VA) and University of California (UC) San Diego School of Medicine were all actively participating in the research. Scientists already say that the results may be a novel strategy for treating neurodegenerative diseases, including memory loss.
Furthermore, they highlight the importance of brain cholesterol. This novel technique is based on by increasing a crucial cholesterol-binding membrane protein in nerve cells and scientists say that it is very effective for the sole reason that it brings cholesterol back to the cell membrane. It is very important for forming new synaptic contacts. This, in turn is crucial for memory formation.
The study focused on a particular cholesterol-binding membrane protein called caveolin-1 (Cav-1) and is said to expand understanding of neuroplasticity – the ability of neural pathways to grow in response to new stimuli. It is not the first study focusing on this specific technique to repair the nerve damage.
The previous research at Veterans Affairs San Diego Healthcare System and at UC San Diego demonstrated that raising caveolin-1 levels supported healthy “rafts” of cholesterol involved in neuron growth and cell signalling. But that study did not finally clarify whether this new growth or neurons actually improved brain function or memory.
As often is the case, mouse models were used in the study. Researchers delivered Cav-1 protein directly into a region of the brain known as the hippocampus of adult and older mice models. The hippocampus is a brain region considered to be very important for the formation of contextual memories (for example, remembering previous shopping when visiting the same store later).
These treated mice demonstrated improved neuron growth, but also showed better retrieval of contextual memories. To test that, scientists used fear – they placed mice in places where they previously received small electric shocks. In the experiments they froze in the place, which is an indication of fear. This shows that the place reminds them of previous bad experiences, which is a sign of contextual memory.
Scientists are already saying that his type of gene therapy may be a path toward treating age-related memory loss, but further investigation is needed. Now researchers are testing this gene therapy in other types of diseases and conditions: they are testing this therapy with mouse models of Alzheimer’s disease and expanding it to possibly treat various injuries, such as spinal cord injury and traumatic brain injury.
This therapy with caveolin-1 protein may be relevant for other types of memory loss as well, such as memory loss due to alcohol and drug use. Chitra Mandyam, co-first author of the study, said: “We’re very interested in studying whether we can manipulate Cav-1 in other areas of the brain”.
Now we can only hope that this novel therapy will soon undergo tests with humans and it will prove to be an effective treatment of memory loss and other conditions. Even marginally improving life quality of these patients would be a great step forward.