Decreased density of synaptic formation in the frontal cortex of neonatal rats exposed to ethanol in utero.

We examined the developing synaptic junctions in the rat frontal cortex in cases of fetal alcohol syndrome, the objective being to determine the synapse-mental retardation relationship. On day 21 of gestation, the ultrastructural synaptic junction revealed no obvious differences between the ethanol-exposed and control rats; however, the number of synapses in ethanol-exposed rats was one third that of the controls. The possible relationship between synaptic density in the frontal cortex and mental development has to be considered.