The term medial orbital gyrus refers to a convolution identified by dissection on the ventral surface of the frontal lobe. In the human it is located between the anterior orbital gyrus laterally and the straight gyrus medially. Its medial boundary is defined by the olfactory sulcus, its lateral boundary by orbital sulci. Rostrally it merges with the frontomarginal gyrus ( Mai-1997 ). In the macaque it extends from the frontal pole to the olfactory tubercle. The medial orbital sulcus separates it from the lateral orbital gyrus, and as in the human, the olfactory sulcus separates it from the straight gyrus ( Martin-2000 ). Equivalent features are not seen in the smooth cerebral cortex of the rat and mouse ( NeuroNames ).