Synaptic Development and Related Disturbances

Characteristics of synaptic development are as follows: 1) an increase‐decrease in the number of synapses consisting of an over‐production followed by elimination, the end product being the maturing form; 2) with maturation, there is a transformation from the axo‐dendritic shaft synapses to the axo‐dendritic spine ones. In early development, synaptogenesis probably proceeds simultaneously with myelination. A suggestion that the critical period giving definitive impairments in the organization of synapses exists may be raised. Quantitative analyses of the mitochondrial number in. the presynapse, determined using conventional osmium tetroxide staining and the number of synaptic junction determined using the EPTA preferential procedure reveal the synaptic changes, both in normal development or in response to nutritional and pharmacological factors.