Bareyre Lab · Lausanne, Switzerland

How the injured spinal cord rewires itself

After incomplete spinal cord injury, severed axons form new detour circuits through relay neurons that bypass the lesion. We study how these circuits form, which connections are kept, and how to guide them toward functional recovery.

See the finding Publications

Fig. 1 Detour circuit after an incomplete thoracic lesion (schematic). Red: the new route to the original target. Dotted: degenerated or pruned connections.

Focus: Spinal cord injury
Mechanism: Detour circuits
Also: Mild repetitive TBI
Model: Rodent SCI & TBI

The finding

Recovery runs through detour circuits

01
Intact projection
Corticospinal (CST) axons run from the motor cortex through the spinal cord to their targets.
02
Incomplete lesion
Injury transects the CST. Severed central axons do not regenerate across the lesion, and the distal segment degenerates.
03
Collateral sprouting
Above the lesion, transected axons sprout new collaterals that contact propriospinal relay neurons — long relays that bridge the injury and short ones that do not.
04
Refinement
Over weeks, contacts onto short relays are eliminated while those onto long relays are kept. The resulting detour circuit carries the signal back to its original target.

Our research questions

An intact corticospinal axon projects to its spinal target1 / 4

Intact projection

Corticospinal (CST) axons run from the motor cortex through the spinal cord to their targets.

Our research questions

Research

Open questions

Outgrowth alone is not enough: regrowing axons must be integrated into reorganised networks. Our programmes ask how that happens.

Research programmes

Approach

From single axons to behaviour

We follow the same circuits across scales — from anatomy, to function, to recovery.

Circuit tracing
Anterograde, retrograde and trans-synaptic viral tracing to map who connects to whom after injury.
Imaging
Confocal and in vivo microscopy to follow individual axons, sprouts and synapses over time.
Genetic & pharmacological tools
Targeted manipulation of neuronal activity and signalling in defined relay populations.
Electrophysiology
Functional confirmation that newly formed connections transmit across the lesion.
Behaviour
Locomotor and skilled-motor testing to link circuit changes to recovery.

Peer-reviewed work