Nora Jamann

Host: prof. Maarten Kole e-mail: m.kole@nin.knaw.nl 

The NIN-Speaker: Nora Jamann PhD student Netherlands Institute for Neuroscience. Department Axonal Signaling.

Title: Thinking fast and slow: Myelin controls the speed and precision of corticothalamic feedback.

Abstract:

Oligodendroglial myelination is essential for fast action potential (AP) propagation and controls the temporal activity patterns of local and long-range neuronal circuits. There is emerging evidence that myelin sheath properties widely differ across brain regions to fine tune temporal delays. However, whether the tuning of delay times by myelin impacts the function of specific circuits in vivo is less well understood.

In my talk, I will show how we tackled this question and investigated the role of myelination for the precision of corticothalamic feedback. Using a combination of a retrograde AAV targeting approach, in vivo juxta-cellular patch-clamp recordings, optogenetics, Neuropixel recording and computational modelling, we studied the contribution of myelination of long- range projections from layer 5 pyramidal neurons in the primary somatosensory cortex (S1) to the posteromedial nucleus of the thalamus (PoM).

I will show that grey matter demyelination of these axons suffices to increase the delay of L5 to PoM propagation of spike bursts, causing jitter of spike timings in the millisecond temporal scale. Finally, we found that the loss of temporal precision impaired the integration of converging postsynaptic inputs, thereby disrupting the coincidence detection function of long-range corticothalamic L5-PoM loops.