The period centers on dissecting the synapse through biochemical and membrane-focused methods, enabling direct study of presynaptic vesicles and synaptic membranes. Researchers pursued functional verification of chemical communication independent of action potentials, while complementary anatomical mapping of key connectivity clarified how signals traverse memory circuits. The era also witnesses the emergence of activity-dependent plasticity concepts, foreshadowing long-term changes in synaptic strength as a core mechanism of learning.