The Japan Monkey Centre Primates Brain Imaging Repository for comparative neuroscience: an archive of digital records including records for endangered species

Abstract

Advances in magnetic resonance imaging (MRI) and computational analysis technology have enabled comparisons among various primate brains in a three-dimensional electronic format. Results from comparative studies provide information about common features across primates and species-specific features of neuroanatomy. Investigation of various species of nonhuman primates is important for understanding such features, but the majority of comparative MRI studies have been based on experimental primates, such as common marmoset, macaques, and chimpanzee. A major obstacle has been the lack of a database that includes non-experimental primates' brain MRIs. To facilitate scientific discoveries in the field of comparative neuroanatomy and brain evolution, we launched a collaborative project to develop an open-resource repository of non-human primate brain images obtained using ex vivo MRI. As an initial open resource, here we release a collection of structural MRI and diffusion tensor images obtained from 12 species: pygmy marmoset, owl monkey, white-fronted capuchin, crab-eating macaque, Japanese macaque, bonnet macaque, toque macaque, Sykes' monkey, red-tailed monkey, Schmidt's guenon, de Brazza's guenon, and lar gibbon. Sixteen postmortem brain samples from the 12 species, stored in the Japan Monkey Centre (JMC), were scanned using a 9.4-T MRI scanner and made available through the JMC collaborative research program (http:// www.j-monke y.jp/BIR/index _e.html). The expected significant contributions of the JMC Primates Brain Imaging Repository include (1) resources for comparative neuroscience research, (2) preservation of various primate brains, including those of endangered species, in a permanent digital form, (3) resources with higher resolution for identifying neuroanatomical features, compared to previous MRI atlases, (4) resources for optimizing methods of scanning large fixed brains, and (5) references for veterinary neuroradiology. User-initiated research projects beyond these contributions are also anticipated.

The Japan Monkey Centre Primates Brain Imaging Repository of high-resolution postmortem magnetic resonance imaging: the second phase of the archive of digital records

“…In summary, the rearing of nonhuman primates and collecting their postmortem brain samples at the JMC can be said to be fully considered according to animal ethics and welfare. (Sakai et al, 2018).…”

“…The T2-weighted images and DTIs were quality-controlled by the authors according to the criteria of previous studies (Sakai et al, 2018), and those with poor quality were excluded from the repository. Diffusion toolkit and Track Viz (http://trackvis.org) (Wang et al, 2007) were used to reconstruct and visualize tractography (Mori et al, 1999).…”

“…In the present phase, we made the following three improvements over the imaging performed in the first phase (Sakai et al, 2018).…”

“…We succeeded in scanning whole large postmortem brains, such as brains of chimpanzees, with high-resolution. There was a brain size limitation in the first phase (Sakai et al, 2018), namely, that it was not possible to image brain samples with a maximum diameter of approximately 70 mm or larger due to the bore diameter limitation of the 9.4-T MRI equipment (approximately 200 mm diameter) (Sakai et al, 2018). In the present study, we were able to scan relatively large brain samples, such as chimpanzee brain samples, using a 9.4-T MRI machine with a wider bore (approximately 300 mm diameter).…”

“…An open-resource repository of nonhuman primate brain images obtained using postmortem (ex vivo) MRI, the Japan Monkey Centre (JMC) Primates Brain Imaging Repository, was recently established not only to facilitate scientific discoveries in the field of comparative neuroscience, but also to provide a standard model for animal ethics, animal welfare, and conservation of brain information of various nonhuman primates (http://www.j-monkey.jp/BIR/index_e.html) (Sakai et al, 2018). Following this, we will introduce up-to-date advances in MRI, as well as their limitations, in primate comparative neuroscience, the necessity for consideration of animal ethics, animal welfare, and conservation, and the characteristics of the JMC Primates Brain Sample Collection.…”