High-fidelity dendritic sodium spike generation in human layer 2/3 neocortical pyramidal neurons

• Published in: Cell reports (Cambridge) 2022-10, Vol.41 (3), p.111500-111500, Article 111500
• Main Authors: Gooch, Helen M., Bluett, Tobias, Perumal, Madhusoothanan B., Vo, Hong D., Fletcher, Lee N., Papacostas, Jason, Jeffree, Rosalind L., Wood, Martin, Colditz, Michael J., McMillen, Jason, Tsahtsarlis, Tony, Amato, Damian, Campbell, Robert, Gillinder, Lisa, Williams, Stephen R.
• Format: Article
• Language: English
• Subjects: axon; dendrite; electrical excitability; evolution; neocortex; neuronal computations
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2022.111500

Dendritic spikes function as cardinal components of rodent neocortical circuit computations. Recently, the biophysical properties of human pyramidal neurons (PNs) have been reported to be divergent, raising the question of whether dendritic spikes have homologous roles in the human neocortex. To directly address this, we made electrical recordings from the soma and apical dendrites of human and rat layer 2/3 PNs of the temporal cortex. In both species, dendritic excitatory input led to the initiation of sodium-channel-mediated dendritic spikes. Dendritic sodium spikes could be generated across a wide input range, exhibited a similar frequency range of activation, and forward-propagated with high-fidelity to implement stereotyped computations in human and rat PNs. However, the physical expansion and complexification of the apical dendritic trees of human PNs allowed the enriched expression of dendritic spike generation. The computational capacity of human PNs is therefore enhanced by the widespread implementation of a conserved dendritic integration mechanism. [Display omitted] •The dendrites of human and rat L2/3 pyramidal neurons generate sodium spikes•Correlative dendritic computations are executed in human L2/3 pyramidal neurons•Human and rat pyramidal neurons have conserved biophysical properties•The larger dendritic tree of human pyramidal neurons enhances computational capacity Gooch et al. perform simultaneous electrical recordings from the dendrites and soma of human and rat layer 2/3 pyramidal neurons of the temporal cortex to reveal that the biophysical properties and dendritic computational operations of human pyramidal neurons are conserved.