Complete muscle denervation triggers compensatory sprouting of a bystander tonic motor neuron in Drosophila larvae
Abstract
larva, most muscles are co-innervated by a tonic (Ib) and a phasic (Is) MN. We show that when all tonic and phasic inputs to a dorsal muscle field are ablated, the surviving tonic MN1 undergoes robust heterosynaptic sprouting and forms ectopic, functional NMJs on fully denervated muscles. This plasticity is not induced by acute or chronic silencing and instead requires physical loss of neighboring MNs. Longitudinal imaging reveals that sprouting begins shortly after larval hatching and expands across development. In contrast, phasic MN-Is shows minimal remodeling within its partially innervated field. Quantitative analyses indicate that MN1 increases its synaptic territory only modestly and redistributes it across native and ectopic targets. These findings define neuron-subtype-specific, injury-dependent rewiring in an intact motor circuit.
Fields of Study & Subjects
Neurobiology and Insect Physiology Research
Transcranial Magnetic Stimulation Studies
Invertebrate Immune Response Mechanisms
Publication details
- Journal / source
- iScience
- Publisher
- Elsevier BV
- Volume
- 29
- Issue
- 8
- Pages
- 116099–116099
- Publication date
- 27 July 2026
- Language
- EN