Theme: Beyond the Neuron: glia, vascular and immune cells

Abstract: The CNS is responsive to an ever-changing environment. Until recently, studies of neural plasticity focused almost exclusively on functional and structural changes of neuronal synapses. In recent years, myelin plasticity has emerged as a potential modulator of neural networks. Myelination of previously unmyelinated axons, and changes in the structure on already-myelinated axons, can have large effects on network function. The heterogeneity of the extent of how axons in the CNS are myelinated offers diverse scope for dynamic myelin changes to fine-tune neural circuits. The traditionally held view of myelin as a passive insulator of axons is now changing to one of lifelong changes in myelin, modulated by neuronal activity and experience.

Myelin, produced by oligodendrocytes (OLs), is essential for normal brain function, as it provides fast signal transmission, promotes synchronization of neuronal signals and helps to maintain neuronal function. OLs differentiate from oligodendrocyte precursor cells (OPCs), which are distributed throughout the adult brain, and myelination continues into late adulthood. OPCs can sense neuronal activity as they receive synaptic inputs from neurons and express voltage-gated ion channels and neurotransmitter receptors, and differentiate into myelinating OLs in response to changes in neuronal activity.

This lecture will explore to what extent myelin plasticity occurs in adult animals, whether myelin changes occur in non-motor learning tasks, especially in learning and memory, and questions whether myelin plasticity and myelin regeneration are two sides of the same coin.

Biography: Ragnhildur Thóra Káradóttir, currently the director of the MS Society Cambridge Centre for Myelin Repair, did her undergraduate degree in Biochemistry at the University of Iceland. For her postgraduate training, she entered the Wellcome Trust 4 year PhD Programme in Neuroscience, at UCL , where she did her PhD with Prof. David Attwell. Immediately, after her PhD she was awarded a Dorothy Hodgkin Fellowship of the Royal Society, and in 2011 she was awarded a Wellcome Trust Career Development Research Fellowship.

Since establishing her lab she has been awarded a number of awards, most recently the Lister Institute Research Prize (one of 5 in the UK), the Allen Distinguished Investigator Award (one of 5 worldwide, first time given outside of USA ) and an ERC consolidator award. In 2015 she was elected to the FENS -Kavli Network of Excellence (one of 20 in Europe) and in 2017 awarded the Fabiane Carvalho Miranda International Prize for the best paper published in the years 2015-2017 in myelin biology and MS related research.

Her main research interest is to understand how neuronal activity can regulate oligodendrocyte precursor cells (OPCs) differentiation and myelin plasticity in health and disease. Her new line of research interest is to determine the changes in myelin and myelin repair throughout the lifespan.