Premium
Brain organization of gorillas reflects species differences in ecology
Author(s) -
Barks Sarah K.,
Calhoun Michael E.,
Hopkins William D.,
Cranfield Michael R.,
Mudakikwa Antoine,
Stoinski Tara S.,
Patterson Francine G.,
Erwin Joseph M.,
Hecht Erin E.,
Hof Patrick R.,
Sherwood Chet C.
Publication year - 2015
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/ajpa.22646
Subject(s) - gorilla , arboreal locomotion , biology , brain size , hominidae , white matter , primate , zoology , ecology , habitat , magnetic resonance imaging , medicine , paleontology , genetics , radiology , biological evolution
Gorillas include separate eastern ( Gorilla beringei ) and western ( Gorilla gorilla ) African species that diverged from each other approximately 2 million years ago. Although anatomical, genetic, behavioral, and socioecological differences have been noted among gorilla populations, little is known about variation in their brain structure. This study examines neuroanatomical variation between gorilla species using structural neuroimaging. Postmortem magnetic resonance images were obtained of brains from 18 captive western lowland gorillas ( Gorilla gorilla gorilla ), 15 wild mountain gorillas ( Gorilla beringei beringei ), and 3 Grauer's gorillas ( Gorilla beringei graueri ) (both wild and captive). Stereologic methods were used to measure volumes of brain structures, including left and right frontal lobe gray and white matter, temporal lobe gray and white matter, parietal and occipital lobes gray and white matter, insular gray matter, hippocampus, striatum, thalamus, each hemisphere and the vermis of the cerebellum, and the external and extreme capsules together with the claustrum. Among the species differences, the volumes of the hippocampus and cerebellum were significantly larger in G. gorilla than G. beringei . These anatomical differences may relate to divergent ecological adaptations of the two species. Specifically, G. gorilla engages in more arboreal locomotion and thus may rely more on cerebellar circuits. In addition, they tend to eat more fruit and have larger home ranges and consequently might depend more on spatial mapping functions of the hippocampus. Am J Phys Anthropol 156:252–262, 2015. © 2014 Wiley Periodicals, Inc.