A New Hope for Age Related Memory Loss

As human beings, our memories are who we are. They tell us about our past, our connections, and our lives. Our memories shape us into what we are today. Undoubtedly, memory loss is equivalent to losing oneself. Memory lapses are frustrating, and studies show that with age, it takes more time to learn as well as recall.

Causes of Age-Related Memory Loss:

  1. Deterioration of the hippocampus – an area of the brain that is involved in the formation and retrieval of memories.
  2. Reduction in the hormones and proteins that repair brain cells and stimulate neural growth.
  3. Decreased blood flow to the brain, which leads to impaired cognitive skills.

Along with age, there are several other reasons such as stress, depression, and vitamin deficiencies, which can trigger memory loss. Keeping our mind and body active contribute to a healthy memory. A study conducted at the American Academy of Neurology shows that older adults who walked six to nine miles per week had more gray matter in their brains nine years after the start of the study than people who didn’t walk as much. This suggests healthy behaviors prevent the risk of cognitive decline.

Recently, Professor James Fawcett at the University of Cambridge, and Dr. Jessica Kwok at the University of Leeds have successfully reversed age-related memory loss in mice. They claim to use this discovery for preventing age-related memory loss in human beings. Their study shows that variations in the brain’s extracellular matrix around the nerve cells lead to memory loss with aging, but with genetic treatments, the process can be reversed.

Perineuronal nets (PNNs), a cartilage-like structure surrounding neurons in the brain, controls the level of the brain’s plasticity (the ability to learn, adapt, and make memories). PNNs contain several compounds known as chondroitin sulfates. Although some inhibit neuroplasticity, others promote it. The balance of these compounds changes with age, affecting our ability to learn and form new memories. Scientists at Cambridge and Leeds investigated whether changing the chondroitin sulfate composition of the PNNs might restore neuroplasticity and alleviate age-related memory deficits.

The team took 20-month-old mice and conducted several tests which showed deficits in the mice memory in comparison to six-month-old mice. In one test, the mouse was placed at the mount of a Y-shaped maze with two similar objects at the end of the two arms. After some time, the mouse was once again placed in the same maze, but with a new object in one arm and the same object in the other arm. The scientists measured the time spent by the mouse exploring each object, to check if it remembered the object from the previous task. The older mouse’s memory was weaker. The researchers used a ‘viral vector’ – a virus capable of manipulating the composition of chondroitin sulfate – on the aging mouse. This fully restored the memory of the older mice. By increasing the amounts of chondroitin 6-sulfate using a viral vector, the older mice’s memory and plasticity were that of younger and healthier mice.

Although the study was conducted on mice, Professor James Fawcett and Dr. Jessica Kwok are confident that the same mechanism will function in humans as the molecules and structures in the human brain are similar to those in rodents’. The team has also identified an oral drug that is licensed for human use and inhibits the formation of PNNs. If successful, this study’s findings will alleviate Alzheimer’s and other memory loss diseases.

 

Sources:

The University of Cambridge. “Scientists Reverse Age-Related Memory Loss in Mice.” ScienceDaily, ScienceDaily, 22 July 2021, www.sciencedaily.com/releases/2021/07/210722113052.htm.