It is often assumed that highly-branched neuronal structures perform compartmentalized computations. Instead, the Gastric Mill (GM) neuron in the crustacean stomatogastric ganglion (STG) operates like a single electrotonic compartment, despite having thousands of branch points and total cable length >10 mm (Otopalik et al., 2017a, b). We now show: 1) that compact electrotonic architecture is generalizable to other STG neuron types, 2) these neurons present direction-insensitive, linear voltage integration, suggesting they pool synaptic inputs across their neuronal structures. 3) Simulations of 720 cable models spanning a broad range of geometries and passive properties show that compact electrotonus, linear integration, and directional insensitivity in STG neurons arise from their neurite geometries (diameters tapering from 10-20 µm to < 2 µm at their terminal tips). A broad parameter search reveals multiple morphological and biophysical solutions for achieving different degrees of passive electrotonic decrement and computational strategies in the absence of active properties.
All computational scripts used for: analysis, visualization, and model simulations, will be promptly posted on the Marder Lab GitHub site (https://github.com/marderlab) upon publication, where it will be freely available to the public. These tools are currently available on A. Otopalik's GitHub site (https://github.com/otopalik/Otopalik-Pipkin-Marder-2019). All source data are publicly available on Dryad (https://dx.doi.org/10.5061/dryad.48pt6jd).
Data from: Neuronal morphologies built for reliable physiology in a rhythmic motor circuitDryad Digital Repository, doi:10.5061/dryad.48pt6jd.
- Adriane G Otopalik
- Eve Marder
- Adriane G Otopalik
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Inna Slutsky, Tel Aviv University, Israel
© 2019, Otopalik et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.