The two body problem: proprioception and motor control across the metamorphic divide

TL;DR

This paper reviews how neural circuits for proprioception and motor control differ and are similar across the larval and adult stages of Drosophila, providing insights into general principles of sensorimotor control and the effects of biomechanics.

Contribution

It offers a comparative analysis of neural mechanisms in larval and adult Drosophila, highlighting common principles and stage-specific differences in sensorimotor control.

Findings

Shared neural principles across developmental stages

Stage-specific adaptations due to biomechanics

Opportunities for cross-species neural circuit comparison

Abstract

Like a rocket being propelled into space, evolution has engineered flies to launch into adulthood via multiple stages. Flies develop and deploy two distinct bodies, linked by the transformative process of metamorphosis. The fly larva is a soft hydraulic tube that can crawl to find food and avoid predators. The adult fly has a stiff exoskeleton with articulated limbs capable of long-distance navigation and rich social interactions. Because the larval and adult forms are so distinct in structure, they require distinct strategies for sensing and moving the body. The metamorphic divide thus presents an opportunity for comparative analysis of neural circuits. Here, we review recent progress toward understanding the neural mechanisms of proprioception and motor control in larval and adult Drosophila. We highlight commonalities that point toward general principles of sensorimotor control and differences that may reflect unique constraints imposed by biomechanics. Finally, we discuss emerging opportunities for comparative analysis of neural circuit architecture in the fly and other animal species.