Given the usefulness of the BigBrain high resolution histological volume, it would be very valuable to have a similar public domain resource for the macaque. Isotropic high resolution data to build such a resource is not currently available, but as an initial step we present a histological volume based on the NIH Blueprint Non-Human Primate (NHP) Atlas , acquired by the Allen Institute and funded by the NIH. Our contribution is to take the set of Nissl stained slices (50 $\mu m$ thick, 250 $\mu m$ apart) and to create a smooth volume by calculating the optimal alignment. We used open tools [2, 3] for processing, modernized the code of the poSSum three-dimensional reconstruction toolbox  and extended the deformable registration method thereof, using the an MRI-based macaque atlas  as a reference template. We will use the reconstructed volume to estimate neuron densities across all cortical areas used in the core-nets.org macaque connectivity database . Besides adding to the body of knowledge on the cytoarchitecture  and geometry of the macaque cortex, this work will provide tools to further analyze histological data and support large-scale dynamical modeling studies.
 NIH Blueprint NHP Atlas, www.blueprintnhpatlas.org
 Bakker et al. Neuroinformatics, 2015
 Microdraw, microdraw.pasteur.fr
 Majka et al. Journal of Comparative Neurology, 2016
 Calabrese et al. NeuroImage, 2015
 Markov et al. Cerebral Cortex, 2012
 Beul and Hilgetag. NeuroImage, 2019