Memory Encoding Mechanism Plus Cell Regeneration

Our experiences and sensory input all that we see, hear, or do- can set off long-term changes in the strength of connections between the synapses, or nerve cells in our brain. These persistent changes are now thought to be how the brain encodes information as memory.

As reported in the journal Neuron, Johns Hopkins researchers have uncovered a new biochemical mechanism for memory storage, one that may have a connection with addictive behavior.

In the past, the long-term changes in connection were thought to only involve a rapid kind of electrical signaling in the brain, electrical blips lasting about one-hundredth of a second. Now, neuroscience professor David Linden, Ph.D., and his colleagues have shown another, much slower form of electrical signaling lasting about a second can also be persistently changed by experience.

Lasting Changes in Slow Nerve Current

Researchers simulated natural brain activity by applying short electrical jolts to slices of rat brain and measuring the current flowing across the cells. After repeated jolting, the strength of the slow nerve signals had dramatically decreased and remained at a low intensity for 30 minutes after electrical jolts ceased.

These slow signals are produced by a nerve cell receptor called mGluR1, which has been associated with behaviors such as addiction and epilepsy.

“Both of these conditions also involve long-term changes in the function of nerve connections,” says Linden. “So in addition to furthering our basic understanding of memory storage, our work suggests that drugs designed to alter mGluR1 are promising candidates for the treatment of addiction, epilepsy, and diseases of memory.”

Cell Regeneration Work

In somewhat related news, research is continuing to make headway in the area of manipulating cell signaling to incite regeneration. This area is separate to the stem cell or gene therapy work also progressing. Researchers from the Department of Cardiology at Children’s Hospital Boston have developed a special patch, which, when placed on a damaged area of the heart, regenerates cardiac cells after heart attack and improves heart function.

The patch contains a substance called periostin, which helps cardiomyocytes divide and multiply. In a heart attack, cardiomycite cells die from lack of blood and oxygen. This damage prevents the heart from working normally. Usually, damaged or dead cardiac tissue cannot regrow.

Which leads me to envison a fusion of these two findings. Imagine being able to regenerate targeted synapses and memory pathways in the brain. The implications are wide-ranging, from autism to addictive personalities, anxiety and compulsion disorders, to the darker side of social engineering and even re-writing history.

Around the Web

This weeks Ground Rounds of medical blogs, number 3.44, is up at, and features our post on Pediatric Sibling Transplants, Ethics and Futility, which was given the Perspectivus Broadendii award, as well as many other interesting medi-blogger posts.

In other news, I was staggered to read the news that eating grapefruit can lead to breast cancer. Eating grapefruit every day could raise the risk of developing breast cancer by almost a third, US scientists say: A study of 50,000 post-menopausal women found eating just a quarter of a grapefruit daily raised the risk by up to 30%. And all it takes is one quarter of a grapefruit a day.

Apparently something in grapefruit may boost blood oestrogen levels by inhibiting a molecule called cytochrome P450 3A4 (CYP3A4), involved in metabolising oestrogen hormones.

So much for the Grapefruit Diet, right?