Toward next-generation primate neuroscience: A collaboration-based strategic plan for integrative neuroimaging

Open science initiatives are creating opportunities to increase research coordination and impact in nonhuman primate (NHP) imaging. The PRIMatE Data and Resource Exchange community recently developed a collaboration-based strategic plan to advance NHP imaging as an integrative approach for multiscale neuroscience.

New insights into the classification and nomenclature of cortical GABAergic interneurons

A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus.

Distinct feedforward and intrinsic neurons in posterior inferotemporal cortex revealed by in vivo connection imaging

We investigated circuits for object recognition in macaque anterior (TE) and posterior inferotemporal cortex (TEO), using a two-step method with in vivo anatomical imaging. In step 1, red fluorescent tracer was injected into TE to reveal and Pre-target patches of feedforward neurons in TEO. In step 2, these were visualized on the cortical surface in vivo, and injected with green fluorescent tracer. Histological processing revealed that patches >500 μm from the injection site in TEO consisted of intermingled green TEO intrinsically projecting neurons and red TEO-to-TE neurons, with only few double-labeled neurons. In contrast, patches near the injection site in TEO contained many double-labeled neurons. Two parallel, spatially intermingled circuits are suggested: (1) TEO neurons having very local intrinsic collaterals and projection to TE (2) TEO neurons projecting more widely in the intrinsic network, but not to TE. These parallel systems might be specialized for, respectively, fast vs. highly processed signals.

Antigenic compartmentation of the primate and tree shrew cerebellum: a common topography of zebrin II in Macaca mulatta and Tupaia belangeri

Despite the apparent uniformity in cellular composition of the adult cerebellar cortex, functional, anatomical, mutational and molecular maps all reveal a complex topography underlying the relatively simple architecture. In particular, zebrin II, a polypeptide antigen identified as aldolase C, is restricted to a subset of Purkinje cells that form a symmetrical and reproducible array of zones and stripes. The vermis of the well-studied rodent cerebellar cortex is divided into four transverse zones--anterior ( approximately lobules I-V), central ( approximately lobules VI and VII), posterior ( approximately lobule VIII) and nodular ( approximately lobules IX and X). Each transverse zone is further subdivided mediolaterally into parasagittal stripes. To gain insight into the evolution of cerebellar compartmentation, the pattern of zebrin II expression has been compared between the primate Macaca mulatta and the tree shrew Tupaia belangeri, and the results related to previous findings from other species. Although the somata of most Purkinje cells in the Macaca cerebellum express zebrin II, parasagittal stripes can still be delineated owing to the alternating high and low zebrin II immunoreactivity in the dendrites. In the macaque vermis, a complex set of zebrin II parasagittal compartments is found in all transverse zones. Unlike in rodents, in which uniform expression domains interrupt heterogeneous zones, zebrin II parasagittal stripes in the macaque cerebellum are seen throughout the vermis. In Tupaia, the parasagittal pattern of zebrin II expression also reveals a striking array of stripes in all lobules. The data suggest that cerebellar compartmentation in Tupaia belangeri more closely resembles that of primates than it does rodents or lagomorphs.