Signaling Neurons Make Neighbor Cells "Want In"

So this is the belief in 'good' neurons. Is it helpful in more than memory neurons? full article at the link.
http://www.scientificamerican.com/article.cfm?id=keeping-up-with-the-neurons
Neurons, or nerve cells, each have a pair of projections—the axon and the dendrite, which transmit and receive impulses, respectively. The dendrite, a treelike structure, has several branches dotted with hundreds synaptic receiving terminals called "spines," each connected to the axons of scores of other neurons. When one of these spines receives stimulation (through the synapse it creates with another cell's axonal projection), the spine expands into the synapse, strengthening the link between its neuron and the other cell. This process of enhanced communication through a synapse is called long-term potentiation (LTP) and is thought to be the basis of learning.
Previous attempts to identify this process were stymied by inexact methods. Researchers primarily used electrical impulses, which do not allow for good spatial observation. Svoboda and study co-author Christopher Harvey, a graduate student in Svoboda's lab, used a more precise technique. They attached a light-absorbing chemical group to the neurotransmitter glutamate (an excitatory chemical messenger in the brain) at a particular synapse in a slice of a rat's hippocampus, the brain region responsible for short-term memory. When they trained a laser on the glutamate, it was freed from its light-absorbing molecular captor and thereby able to resume its function; it went to the dendritic spine in the synapse, allowing ions to enter the cell and an electrical signal to be generated.
As a result of this stimulation, the spine stretched farther into the synapse. Researchers did not find any evidence that neighboring spines had also expanded, but they did find that it took less stimulation—only 20 percent of the original prodding—to prompt any of the 20 spines within 10 microns (around four ten-thousandths of an inch) to undergo LTP. This effect appeared to last for five to 10 minutes, the scientists report.