Abstract
Much work has explored animal-to-animal variability and compensation in ion channel expression. Yet, little is known regarding the physiological consequences of morphological variability. We quantify animal-to-animal variability in cable lengths (CV = 0.4) and branching patterns in the Gastric Mill (GM) neuron, an identified neuron type with highly-conserved physiological properties in the crustacean stomatogastric ganglion (STG) of Cancer borealis. We examined passive GM electrotonic structure by measuring the amplitudes and apparent reversal potentials (Erevs) of inhibitory responses evoked with focal glutamate photo-uncaging in the presence of TTX. Apparent Erevs were relatively invariant across sites (mean CV ± SD = 0.04 ± 0.01; 7-20 sites in each of 10 neurons), which ranged between 100-800 µm from the somatic recording site. Thus, GM neurons are remarkably electrotonically compact (estimated λ > 1.5 mm). Electrotonically compact structures, in consort with graded transmission, provide an elegant solution to observed morphological variability in the STG.
Highlights
Neuronal circuits can generate stable output despite variable underlying parameters across animals (Marder and Goaillard, 2006; Marder, 2011)
We investigated the physiological consequences of animal-to-animal variability in neuronal morphology in the crab stomatogastric ganglion (STG), a central pattern-generating circuit composed of 26–27 neurons
The stomatogastric ganglion (STG) of the crab Cancer borealis is composed of 26–27 neurons situated around a dense neuropil region, wherein each of the neurons branches extensively
Summary
Neuronal circuits can generate stable output despite variable underlying parameters across animals (Marder and Goaillard, 2006; Marder, 2011). A neuron’s distributed, geometric cable properties: the length, diameter, taper, and branching of its neurites, shape passive current flow and voltage propagation (Rall, 1959, 1977; Goldstein and Rall, 1974) This resulting electrotonic structure plays a central role in determining whether voltage signals arising at disparate sites across the dendritic tree are integrated or segregated (Rall, 1959, 1967, 1969a, 1969b; Rall and Rinzel, 1973, 1974; Goldstein and Rall, 1974; Agmon-Snir and Segev, 1993; Vetter et al, 2001). Ion channel expression, when superimposed on morphology, gives rise to neuronal physiology, input-output computations, and circuit-level function (for reviews, see Koch and Segev, 2000; London and Hausser, 2005)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
