Enhanced Dendritic Compartmentalization in Human Cortical Neurons

Abstract

Summary The biophysical features of neurons shape information processing in the brain. Cortical neurons are larger in humans than in other species, but it is unclear how their size affects synaptic integration. Here, we perform direct electrical recordings from human dendrites and report enhanced electrical compartmentalization in layer 5 pyramidal neurons. Compared to rat dendrites, distal human dendrites provide limited excitation to the soma, even in the presence of dendritic spikes. Human somas also exhibit less bursting due to reduced recruitment of dendritic electrogenesis. Finally, we find that decreased ion channel densities result in higher input resistance and underlie the lower coupling of human dendrites. We conclude that the increased length of human neurons alters their input-output properties, which will impact cortical computation.

Robust perisomatic GABAergic self-innervation inhibits basket cells in the human and mouse supragranular neocortex

“…However, among various cellular features characterized in humans but not in rodent neocortex (Blazquez-Llorca L et al 2010;Testa-Silva G et al 2010;Molnar G et al 2016;Szegedi V et al 2016;Wang B et al 2016;Beaulieu-Laroche L et al 2018;Boldog E et al 2018;Goriounova NA et al 2018;Kalmbach BE et al 2018;Pruunsild P and H Bading 2019), human neocortical neurons exhibit higher Rm than their rodent counterparts do (Eyal G et al 2016;Poorthuis RB et al 2018). Although our data here showed that human and mouse pvBC input resistance values were not different on average (showing p value of 0.10), human neurons had individual cells showing clearly higher Rm than did those found in any of the mouse pvBCs (Poorthuis RB et al 2018).…”

Transcriptomic evidence that von Economo neurons are regionally specialized extratelencephalic-projecting excitatory neurons

“…A major challenge in understanding human brain cellular and circuit function is a paucity of tools, techniques, and tissue. However, techniques for physiological and morphological analysis using in vitro slice preparations and patch clamp physiology work robustly on human tissue from neurosurgical resections 52,53,54,55,56,57,58 . Although it is exceedingly rare for tissue to be removed from regions like FI and ACC during such surgeries, the instances in which such specimens can be collected for research purposes represent rare opportunities to collect highly valuable data in the spirit of case studies in disease, where even sparse data can provide important observations and generate testable hypotheses.…”

Dendritic GABAB receptors control nonlinear information transfer along the dendro-somatic axis in layer 5 pyramidal neurons

“…The voltage-dependent deactivation of IH appeared to be an important factor mediating the nonlinear Kds. At rest, IH decreases the impact of small EPSPs evoked in the distal dendrite at the soma (Golding et al, 2005;George et al, 2009) and contributes to increased compartmentalization of synaptic inputs (Harnett et al, 2015) that has also been observed in human L5 neurons (Beaulieu-Laroche et al, 2018).…”