Working with human brain tissue removed in surgery, researchers have identified the components of a critical part of the brain’s architecture: the synapse, or junction where one neuron makes a connection with another.

The work should help in understanding how the synapse works in laying down memories, as well as the basis of the many diseases that turn out to be caused by defects in the synapse’s delicate machinery.

The research team, led by Seth Grant of the Sanger Institute near Cambridge, England, compiled the first exact inventory of all the protein components of the synaptic information-processing machinery. No fewer than 1,461 proteins are involved in this biological machinery, they report in the current issue of Nature Neuroscience.

They have tied their catalog into the human genome sequence, connecting each protein to the gene that contains instructions for making it. This has allowed them to compare their findings in humans with other species whose genomes have been sequenced, such as the Neanderthals, who “would have suffered from the same range of psychiatric disease as humans,” Dr. Grant said.