Washington, June 27 (IANS) Do you have a tough time figuring out where you placed your car keys or recalling names at a cocktail party? Researchers have now pinpointed the elusive molecule that holds the key to the process by which memories are stored in the brain.

The brain is made up of billions of neurons or nerve cells that communicate with one another through structures called synapses, the junction between neurons.

Synapses convey electrical signals from the 'sender' neuron to the 'receiver' neuron. A strong synapse has a large effect on its target cell, a weak one has little effect, reports the Journal of Neuroscience.

John Lisman, professor of biology and neuroscience at Brandeis University, who led the study, helps explain how memories are stored at synapses.

His work builds on previous studies showing that changes in the strength of these synapses are critical in the process of learning and memory, according to a Brandeis statement.

"You can actually now see that when learning occurs, some synapses become stronger and others become weaker," Lisman says.

But what is it that controls the strength of a synapse?

Lisman's lab has discovered that the amount of a molecular complex (CaMKII/NMDAR complex) actually determines how strong a synapse is, and, most likely, how well a memory is stored.

"We're claiming that if you looked at a weak synapse you'd find a small number of these complexes, maybe one," says Lisman. "But at a strong synapse, you might find many of these complexes."