Hippocampal dendritic abnormalities in a rat model of phenylketonuria

An increased concentration of dendritic spines was present in one region of the hippocampus in rats made hyperphenylalaninemic (phenylketonuria model). It is uncertain whether this finding resulted from an actual hyperplasia or a failure of maturational spine reduction. The result is unusual in that Golgi studies of most mental retardation syndromes and relevant animal models have shown loss of dendritic spines.