Medial wall of the right temporal horn. The choroidal fissure is a cleft made of a thin layer of pia and ependyma, that is located between the thalamus (in this region, the lateral geniculate nucleus) and the fornix, and begins at the inferior choroidal point posterior to the head of the hippocampus. The inferior choroidal point communicates the ambient cistern with the temporal horn and is the point of entry of the anterior choroidal artery, which supplies the choroid plexus of the temporal horn, among other structures. The uncal recess separates the hippocampus from the amygdala, which forms the anterior wall of the temporal horn. (Image courtesy of AL Rhoton, Jr.)