PT  - JOURNAL ARTICLE
AU  - Alberto Lazari
AU  - Piergiorgio Salvan
AU  - Michiel Cottaar
AU  - Daniel Papp
AU  - Matthew Rushworth
AU  - Heidi Johansen-Berg
TI  - Hebbian activity-dependent plasticity in white matter
AID  - 10.1101/2022.01.11.473633
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.01.11.473633
4099  - http://biorxiv.org/content/early/2022/01/12/2022.01.11.473633.short
4100  - http://biorxiv.org/content/early/2022/01/12/2022.01.11.473633.full
AB  - Synaptic plasticity is required for learning and follows Hebb’s Rule, the com-putational principle underpinning associative learning. In recent years, a complementary type of brain plasticity has been identified in myelinated axons, which make up the majority of brain’s white matter. Like synaptic plasticity, myelin plasticity is required for learning, but it is unclear whether it is Hebbian or whether it follows different rules. Here, we provide evidence that white matter plasticity operates following Hebb’s Rule in humans. Across two experiments, we find that co-stimulating cortical areas to induce Hebbian plasticity leads to relative increases in cortical excitability and associated increases in a myelin marker within the stimulated fiber bundle. We conclude that Hebbian plasticity extends beyond synaptic changes, and can be observed in human white matter fibers.Competing Interest StatementThe authors have declared no competing interest.