Mapping the distribution of neurochemically-defined cell types throughout the primate cortex
The contributions of neurons to perception, action, or cognition are fundamentally determined by the connections they form with other neurons. While the recent connectivity maps of non-human primate species have been a major achievement, to provide the border insight into brain dynamics, the connectivity patterns need to be also analysed in the context of chemo- and cytoarchitecture. We present a whole-brain map of Calbindin positive (CB+) neurons including the neurogliaform (NG) subtype. The densities of the CB+ neurons were measured in three marmosets using a deep learning approach which provides insight into, both, interareal and laminar density distribution. While the absolute densities vary significantly between individuals, the overall patterns remain consistent. The density of CB+ neurons across the neocortex followed a similar pattern as overall neuronal density, while NG neurons had a more localised presence. In the long term, the systematic mapping of neuronal types in non-human primates will provide a relationship between the system and molecular organization of the cerebral cortex.