The validity of congenital helplessness as a genetic rat model for human de
pression was investigated in cortical regions of the rat brain thought to b
e analogous to those showing abnormalities in human neuroimaging studies. C
ortex metabolism was analyzed using quantitative cytochrome oxidase histoch
emistry. Congenital helpless rats showed changes in frontal and cingulate r
egions comparable to those that have demonstrated metabolic differences in
human depression. Significant metabolic decreases were found in dorsal fron
tal, medial orbital, and anterior cingulate, whereas a significant increase
was found in infraradiata (subgenual) cingulate. The direction of these ch
anges were the same as those seen in human studies. These findings support
the validity of congenital helplessness as a model for human depression. Ne
uroReport 11:3793-3798 (C) 2000 Lippincott Williams & Wilkins.