Neuroglial proteoglycan NG2 immunoreactivity in the cingulate cortex is significantly increased in BTBR brain. Quantitative image analysis of NG2 expression in the anterior cingulate cortex (ACC) of the BTBR mouse compared with the B6 mouse. Histogram illustrates measurement of percentage NG2 stained area from three sections per animal in the region of the ACC and the striatum. This resulted in a significant increase in the area of NG2 immunoreactivity in BTBR versus B6 mice. (*P = 0.0088, n = 6 mice per strain). No significant change in the expression of NG2 in the striatum was seen in the same animals. The coronal section illustrates the regions of interest chosen for image analysis: ACC (large rectangle) and striatum (small rectangle).