engleski

Postnatal development of dendritic spines on layer III pyramidal neurons in the human prefrontal cortex

The aim of our study was to obtain data on the development of the prospective postsynaptic elements on layer IIIC pyramidal neurons in the region of Brodmann's area 9 of the human prefrontal cortex (PFC). We have analyzed changes in the density of dendritic spines during postnatal life using Golgi- rapid method. The quantitative analysis was performed on apical, apical oblique and basal dendrites. Dendritic spines were rarely observed in the first three months of postnatal life, but their number significantly increased during the 7th month. The density became highest between the age of 15 months and 5 years. The high number of spines was maintained up to the 16 years of life. This period was followed by a decline in the number of dendritic spines. The density stabilized in the third decade of life, on values 40% less than the highest value, and remained stable during lifetime. In the early postnatal life, immature, hair-like forms of dendritic spines were predominant, showing no signs of maturity and adult- like properties until the age of 5. These results showed that the development of dendritic spines in the human PFC follows the general pattern of the development of synapses and receptors in the monkey and human PFC, where the phase of overgrowth is followed by a decline in the number of circuitry elements. The overproduction of neuronal circuitry elements in the human PFC coincides with the development of cognitive functions. The prolonged structural maturation of layer IIIC pyramidal neurons in the human PFC corresponds to the prolonged chemical maturation of these neurons, indicating possible plasticity of associative elements during the whole period of cognitive maturation.

dendritic spines ; synapse ; prefrontal cortex ; human ; pyramidal neurons ; cognition ; Golgi method

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