Learning, Memory, And Progress Toward A Living Chip

Itay Baruchi and Eshel Ben-Jacob of Tel-Aviv University used an array of electrodes to monitor the firing patterns in a network of linked neurons. As previous studies have shown, simply linking the neurons together leads them to spontaneously fire in coordinated patterns. In the study published in the journal Physical Review E the researchers found that they could deliberately create additional firing patterns that coexist with the spontaneous patterns. They claim that these new firing patterns essentially represent simple memories stored in the neuron network.

To create a new memory in the neurons, the researchers introduced minute amounts of a chemical stimulant into the culture at a selected location. The stimulant induced a second firing pattern, starting at that location. The new firing pattern in the culture along coexisted with the original pattern. Twenty-four hours later, they injected another round of stimulants at a new location, and a third firing pattern emerged. The three memory patterns persisted, without interfering with each other, for over forty hours.

In addition to producing the first chemically operated neuro-memory chip, the researchers propose that their work implies that chemical stimulation may be crucial to learning and memory formation in living organisms.