Complex sentence: In lower mammals, the hippocampus is dorsally located but considerable expansion of the cerebral cortex in higher mammals including humans displaces the hippocampus ventrally where it protrudes inferiorly into the lateral ventricles.
Split into simpler sentences: In lower mammals, the hippocampus is dorsally located. Due to the considerable expansion of the cerebral cortex in humans and higher mammals, the hippocampus is displaced ventrally and protrudes into the inferior lateral ventricles.