Synapses have been identified, segmented and quantified in the human neocortex (trans entorhinal cortex, TEC) with 3D electron microscopy (FIB-SEM). Layer II of the TEC has been studied. 5 cases have been used (AB1, AB2, IF10, M16 and M17) to achieve a total of 15 valid images stacks. Data obtained include the number of asymmetric and symmetric synapses, their sizes and their spatial distribution. The distribution of their post-synaptic targets has also been determined.