Genetic scientists in Germany may have discovered the key to a clinical cure for the loss of learning and memory abilities suffered in old age, writes Keith Nuthall.
A research team at the Max Planck Institute for Experimental Medicinein Gottingen claims that its test has highlighted a neuro-physiological process explaining these mental losses.
What is more, the scientists said that they were able to make older mice more intelligent by reducing the production of a protein in the hippocampus area of the brain, which is known to be very active in learning and memory functions. This "calcium-activated potassium channel" protein, or "SK3", can block electrical signals to cells involved in thinking.
By reducing its production, researchers were able to increase the intelligence of the older mice. To achieve this, they exploited the fact that there is nothing automatic about the production of SK3 - like all actions, it has to be ordered by brain messages made from RNA, (a chain of nucleotides).
The researchers injected customised RNA into the hippocampus to jam those existing RNA messages telling mice brain cells to create SK3.
This was tested by electric shock treatment. Mice were exposed to a defined tone and then given a shock to their feet a few seconds later.
The following day, the mice were played the tone without the shock, and while the young (four-to-six-months-old) mice froze in expectation of being hurt, untreated older mice (22-24 months) had never worked out that the sound equalled pain and continued to scuttle about.
But the treated older mice were as sharp as their younger brethren, and were rooted to the spot on cue.
Thomas Blank, a researcherat the Max Planck Institute said: "An intervention that selectively reduces the function of SK3 channels may...
be a novel mechanistic approach for pharmacological treatments that might relieve or even prevent memory deficits associated with ageing."
The report was published in Nature Neuroscience.