The time is ripe to reverse engineer an entire nervous system: simulating behavior from neural interactions

TL;DR

This paper advocates for reverse engineering the entire nervous system of C. elegans by comprehensively understanding neuronal input-output functions through advanced optophysiology, enabling simulation of behavior from neural interactions.

Contribution

It proposes that complete characterization of neuronal IO-functions in C. elegans is feasible and can be used to simulate its behavior, bridging neuroscience and engineering principles.

Findings

Complete neuronal IO-functions can be identified in C. elegans.

Optophysiology enables non-invasive, scalable neural activity control and measurement.

Pooling data across individuals accounts for variability in neuronal function.

Abstract

Just like electrical engineers understand how microprocessors execute programs in terms of how transistor currents are affected by their inputs, neuroscientists want to understand behavior production in terms of how neuronal outputs are affected by their inputs and internal states. This dependency of neuronal outputs on inputs can be described by a state-dependent input-output (IO)-function. However, to reliably identify these IO-functions, we need to perturb each input and combinations of inputs while observing all the outputs. Here, we argue that such completeness is possible in C. elegans; a complete description that goes all the way from the activity of every neuron to predict behavior. The established and growing toolkit of optophysiology can non-invasively capture and control every neuron's activity and scale to countless experiments. The information from many such experiments can be pooled while capturing the inter-individual variability because neuronal identity and function are largely conserved across individuals. Just like electrical engineers use transistor IO-functions to simulate program execution, we argue that neuronal IO-functions could be used to simulate the impressive breadth of brain states and behaviors of C. elegans.