Synaptogenesis in the Prefrontal Cortex of Rhesus Monkeys

作者：Jean‐Pierre Bourgeois, Patricia S. Goldman‐Rakic, PASKO T. RAKIC · 发表于：Cerebral Cortex · 年份：1994 · DOI：10.1093/cercor/4.1.78 · 被引用次数：692 · 研究领域：Neural dynamics and brain function、Neuroscience and Neuropharmacology Research、Neuroscience and Neural Engineering

Since the turn of the century, the prefrontal association areas of the cerebral cortex have been thought to be among the last regions of the cortical mantle to develop. We have examined the course of synaptogenesis in the macaque prefrontal cortex by quantitative electron microscopic analysis in 25 rhesus monkeys ranging in age from embryonic day 47 (E47) to 20 years of age. A series of overlapping electron micrographs spanning the whole cortical thickness in each animal provided data on the number, the proportion, and the density of synapses per unit area (NA) and per unit volume (NV) of neuropil. The tempo and kinetics of synapse formation in prefrontal cortex closely resemble those described for sensory and motor areas, particularly during the stages of synapse acquisition and overproduction (Rakic et al., 1986). In young embryos, we describe a precortical phase (E47-E78), when synapses are found only above and below, but not within, the cortical plate. Following that, there is an early cortical phase, from E78 to E104, during which synapses accumulate within the cortical plate, initially exclusively on dendritic shafts. The next rapid phase of synaptogenesis begins at 2 months before birth and ends approximately at 2 months after birth, culminating with a mean density of 750 million synapses per cubic micrometer. This accumulation is largely accounted for by a selective increase in axospine synapses in the supragranular layers. The period of explosive synaptic density is ...