Fig. 3

Neuronal soma volume frequency distribution. Comparison of neuronal soma frequency distribution in dup(15) autism group (9–26 years old), idiopathic autism (IA) group (8–39 years old) and control group (8–33 years old). Graphs arranged in order from the smallest to the largest neurons demonstrate a significant (asterisks) shift towards small neurons in the nucleus accumbens (Acc), amygdala (Amy), thalamus (Th), CA3 and CA4 sectors in the Ammon’s horn, second layer in the entorhinal cortex (EC2) and the globus pallidus external (GPEx) in the dup(15) group (segment-line) in comparison to age-matched control subjects (continuous line). However, at this age, the difference in neuronal body volume distribution in these structures is not significant when subjects with idiopathic autism (IA) (dot-line) are compared to control subjects (C). The shift to smaller neurons was significant in the dup(15)/A cohort when compared with IA in the amygdala, CA3 and CA4 sectors, and the globus pallidus external. A similar shift in the thalamus did not reach significance level but is consistent with the trend observed in other structures