By: Diana Aguiar de Sousa, Martin Dichgans and Keith Muir

twitter: #GSSW @Diana_A_Sousa

ESO Garmisch Stroke Science Workshop 2021

Opening keynote lecture: “Regulation of brain energy supply by precapillary sphincters and capillary pericytes”, by Martin Lauritzen

In the face of the evolving pandemic situation, it was with great reluctance that the 6th Garmisch ESO Stroke Science Workshop was converted into a fully digital event at the very final stage of preparation.

However, as the Danish philosopher Kierkegaard once remarked, Life can only be understood backwards; but it must be lived forwards. So, it was with Kierkegaard’s hopeful faith that we took the leap into a virtual workshop, believing that the interactive and collaborative atmosphere of this special meeting could still be delivered in digital format.

The opening keynote lecture by Prof. Martin Lauritzen was a delightful confirmation of that hypothesis.  In his talk, the renowned Danish researcher reviewed the state of the art on the “Regulation of brain energy supply by precapillary sphincters and capillary pericytes”, including recent advances in the understanding of microvascular function in models of ischemic penumbra.

Using two-photon microscopy data, including an amazing set of photographs and videos, Prof. Lauritzen highlighted recent evidence from his Laboratory suggesting that brain capillaries do have control mechanisms for blood flow regulation. Indeed, rises in synaptic activity in mouse somatosensory cortex evoke capillary dilation that mostly starts in capillaries before arterioles. The capillary dilation is initiated at precapillary sphincters and at 1st or 2nd order capillaries, from where it propagates upstream to the penetrating arteriole and downstream to higher order capillaries. This has been also shown in pathological conditions, such as cortical spreading depolarization, in which the sphincters and capillaries contract. Moreover, vaso-responsivity of the microcirculation decreases with aging, accompanied by an age-dependent decrease in capillary density and loss of pericyte processes. In the last part of his talk, Prof. Lauritzen demonstrated the value of advanced microscopy techniques for a novel understanding of neurovascular function in stroke models. While there is evidence that global ischemia constricts precapillary sphincters and 1st order capillary pericytes, the penumbra perfusion patterns are heterogeneous and time-variant, raising significant technical challenges.

At the end of the lively discussion that followed his talk, Prof. Lauritzen invited the participating stroke researchers to share their suggestions on disease models that could be assessed by the experimental approaches he had presented (although stressing that much work was involved in setting up disease model systems). He also emphasised that detailed mapping would be necessary to understand the spatial distribution of different responses.

Although we miss the beautiful landscapes of Bavaria, this evening keynote lecture demonstrated that we can still have science at its best, lively discussions and cool wool clothing directly from our home offices. Another good news is that these exciting lectures will be made available to all ESO members in the ESO educational platform – eSTEP – after the meeting. We are looking forward to a full-packed day of top science sessions tomorrow.