ELSC News

Article of the Month, December 2017 (Segev's lab)

November 30, 2017

Comprehensive Morpho-Electrotonic Analysis Shows 2 Distinct Classes of L2 and L3 Pyramidal Neurons in Human Temporal Cortex


Authors: Deitcher et al. (Idan Segev's lab)
Published on November 2017 in Cerebral Cortex
Summary:
In the last several decades we have become closely acquainted with the basic building blocks (cells and synapses) of the rodents’ neocortex. Yet, very little is known about these building blocks in the human neocortex. The present study utilized a rare dataset of 60 3D reconstructed pyramidal cells (PCs) from layers 2 and 3 (HL2/3) of the human temporal cortex; these cells were removed after brain surgery. Employing several statistical methods, including a novel descriptor for dendritic topology, we found that many morphological features showed a significant gradual increase in depth from the pia (e.g., dendritic length, soma radius). In contrast, both active and passive biophysical features (e.g., spikes shape and rates, input resistance, membrane time constant) were depth-independent. Interestingly, L2/3 in human could be classified into two distinct morphological types, termed hereby as “slim-tufted” and “profuse-tufted” PCs; these two morphological classes are also distinct in their electrical properties - the “profuse-tufted” cells tend to fire at higher rates. This is the first systematic study that characterized morpho-electrical cell-types in the human brain; it is part of the recently announced global effort to discover and catalog the brain’s “parts list” (the NIH “cell-census” project (https://www.nih.gov/news-events/news-releases/nih-brain-initiative-launches-cell-census).

 

AOM Segev 122017