Hebb's concept of synaptic plasticity and neuronal cell assemblies.

Both in vertebrates and in invertebrates the study of processes of plasticity in nervous systems have led to consistent models of molecular mechanisms for the so-called Hebb's synapse. Changes of synaptic efficacy will lead to changes in the properties of assemblies of nerve cells--as seen today the correlates of purport. Donald Hebb's view of the characteristics of such assemblies appears farsighted.