RT Journal Article
SR Electronic
T1 Common micro- and macroscale principles of connectivity in the human brain
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.09.14.459604
DO 10.1101/2021.09.14.459604
A1 Lianne H. Scholtens
A1 Rory Pijnenburg
A1 Siemon C. de Lange
A1 Inge Huitinga
A1 Martijn P. van den Heuvel
A1 Netherlands Brain Bank (NBB)
YR 2021
UL http://biorxiv.org/content/early/2021/09/15/2021.09.14.459604.abstract
AB The brain requires efficient information transfer between neurons and between large-scale brain regions. Brain connectivity follows predictable organizational principles: at the cellular level, larger supragranular pyramidal neurons have larger dendritic trees, more synapses, more complex branching and perform more complex neuronal computations; at the macro-scale, region-to-region connections are suggested to display a diverse architecture with highly connected hub-areas facilitating complex information integration and computation. Here, we explore the hypothesis that the branching structure of large-scale region-to-region connectivity follows similar organizational principles as known for the neuronal scale. We examine microscale connectivity of basal dendritic trees of supragranular pyramidal neurons (300+) across ten cortical areas in five human donor brains (1M/4F). Dendritic complexity was quantified as the number of branch points, tree length, spine count, spine density and overall branching complexity. High-resolution diffusion-weighted MRI was used to construct ‘white matter trees’ of cortico-cortical wiring. Examining the complexity of the resulting white matter trees using the same measures as for dendritic trees shows multimodal association areas to have larger, more complexly branched white matter trees than primary areas (all p<0.0001) and regional macroscale complexity to run in parallel with microscale measures, in terms of number of inputs (r=0.677, p=0.032), branch points (r=0.790, p=0.006), total tree length (r=0.664, p=0.036) and branching complexity (r=0.724, p=0.018). Our findings support the integrative theory that brain connectivity is structured following similar ‘principles of connectivity’ at the neuronal and macroscale level, and provide a framework to study connectivity changes in brain conditions at multiple levels of brain organization.Competing Interest StatementThe authors have declared no competing interest.