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Biller, L.

Publications and source records attributed to Biller, L..

2 recordsLinked to original sources

Closed-loop beta stimulation enhances beta activity and motor behaviour

Movement-related beta event-related synchronization (ERS) has been linked to motor control and learning, showing potential as a therapeutic target for those with movement deficits, such as stroke survivors. However, whether directly modulating beta ERS can causally influence motor performance remains unclear, largely due to the lack of methods designed to specifically target this neural activity. To address this gap, we developed a novel behaviourally-driven, closed-loop transcranial alternating current stimulation (tACS) approach to target movement-related beta ERS during a visuomotor adaptation task. We found that the behaviourally-driven, closed-loop beta-tACS specifically enhances beta ERS without affecting beta event-related desynchronization (ERD). Critically, this targeted enhancement significantly improves retention of motor adaptation. These findings establish a causal relationship between beta ERS and motor behaviour and highlight the potential of behaviourally-driven beta-tACS as a therapeutic approach for improving motor function in clinical populations characterized by impaired beta activity.

neuroscience↗

Cytoskeletal assembly in axonal outgrowth and regeneration analyzed on the nanoscale

The axonal cytoskeleton is organized in a highly periodic structure, the membrane-associated periodic skeleton (MPS), which is essential to maintain the structure and function of the axon. Here, we use stimulated emission depletion microscopy (STED) of primary rat cortical neurons in microfluidic chambers to analyze the temporal and spatial sequence of MPS formation at the distal end of growing axons and during regeneration after axotomy. We demonstrate that the MPS does not extend continuously into the growing axon but develops from patches of periodic {beta}-spectrin II arrangements that grow and coalesce into a continuous scaffold. We estimate that the underlying sequence of nucleation, elongation, and subsequent coalescence of periodic {beta}-spectrin II patches takes around 15 hours. Strikingly, we find that development of the MPS occurs faster in regenerating axons after axotomy and note marked differences in the morphology of the growth cone and adjacent axonal regions between regenerating and unlesioned axons. Moreover, we find that inhibition of the spectrin-cleaving enzyme calpain accelerates MPS formation in regenerating axons and increases the number of regenerating axons after axotomy. Taken together, we provide here a detailed nanoscale analysis of MPS development in growing axons.

neuroscience↗