Variable temporoinsular cortex neuroanatomy in primates suggests a bottleneck effect in eastern gorillas

摘要: We describe an atypical neuroanatomical feature present in several primate species that involves a fusion between the temporal lobe (often including Heschl's gyrus great apes) and posterior dorsal insula, such portion of insular cortex forms isolated pocket medial to Sylvian fissure. assessed frequency this 56 (including apes, Old World monkeys, New strepsirrhines) by using either magnetic resonance images or histological sections. A insula was 22 (seven two four nine strepsirrhines). The temporoinsular observed most eastern gorilla (Gorilla beringei G. b. graueri) specimens (62% 100% cases, respectively) but seen less frequently other apes never found humans. further explored histology gorillas examining cyto- myeloarchitecture within region degree which deep cortical layers white matter are incorporated into varies among individuals species. suggest is example relatively rare has become more common gorillas, possibly as result population bottleneck effect. Characterizing phylogenetic distribution morphology highlights derived these apes.