Dendritic spines and immunoreactivity of synaptophysin in the frontal cortex of humans with infantile brain damage. A correlative study.

Some neurodegenerative disorders of adults involving mental retardation are associated with reduction of dendritic spines and number of synapses. A study was performed to prove the changes in the density of dendritic spines and synaptophysin-immunoreactive granules in the frontal cortex of cases with infantile brain damage and a possible correlation between them. Specimen from cortex of children and adolescents with severe mental retardation, aged 3 to 24 years and a group of non-psychiatric age-matched controls were processed according to the Golgi-Kopsch method. Density of dendritic spines on the apical dendrites of layer V pyramidal neurons (Brodman area 10) was analysed in correlation to the density of synaptophysin-reactive granules (counts/microns 2) in the same region. Both density of spines and number of immunoreactive granules were reduced in brains with infantile damages, but there was no correlation between spine density and the number of immunoreactive granules against synaptophysin.