gms | German Medical Science

72. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

06.06. - 09.06.2021

A novel technique for in vivo live cell imaging of the cellular components of the neurovascular unit (NVU)

Eine neue Technik für in vivo live Untersuchung der zellulären Bestandteile der neurovaskulären Einheit (NVU)

Meeting Abstract

  • presenting/speaker Christian Uhl - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Adnan Ghori - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Kim Fischer - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Asylkhan Rakhymzhan - Deutsches Rheuma-Forschungszentrum, Berlin, Deutschland
  • Melina Nieminen-Kelha - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland
  • Peter Vajkoczy - Charité Universitätsmedizin, Klinik für Neurochirurgie, Berlin, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 72. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgie. sine loco [digital], 06.-09.06.2021. Düsseldorf: German Medical Science GMS Publishing House; 2021. DocP158

doi: 10.3205/21dgnc441, urn:nbn:de:0183-21dgnc4412

Veröffentlicht: 4. Juni 2021

© 2021 Uhl et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objective: Treatment of ischemic stroke is limited to mechanical and pharmaceutical recanalization of the affected vessel. Cure of post ischemic tissue, aiming at conservation and rehabilitation of the NVU and functional recovery is non-existent in clinical context. Lack of understanding of molecular processes in these areas following hypoxia is in parts responsible for the shortage of possible treatments. We intended to use two-photon excitation microscopy (2PM) to illuminate the single components of the NVU in a post ischemic context via chronic cranial windows (CCW) in vivo and thereby aimed at enhancing the understanding of specific processes following ischemia in the brain.

Methods: We performed a distal middle cerebral artery occlusion as well as a fronto-lateral CCW implantation. For the window, we either used a glass plate or a silicone-based polydimethylsiloxane (PDMS) membrane. For imaging of vessels, either Cascade Blue® or FITC-Dextran was administered intravenously. For imaging of astrocytes, Sulforhodamine 101 (SR101) was applied intravenously, subpially or intracortically before the respective measurement time points, either via the PDMS membrane or a separate burrhole on the contralateral side. To complete imaging of the NVU, we examined transgenically modified Thy-1 mice, which expressed YFP-positive neurons (Thy-1-CreERT2/Efnb2 lox/lox). These mice further had possibility of an induced knockdown of the ephrinB2 signaling pathway. To add a fourth component, display of the dura was effectuated by the use of second harmonic generation (SHG).

Results: Cascade Blue® proved to be advantageous over FITC-Dextran in physiological circumstances, due to its differing light-spectrum compared to the YFP-expressing neurons. Yet, for the virtue of its minor molecularity, Cascade Blue® tended to extravasate more than the heavier FITC-Dextran, following breakdown of the NVU. We found the ideal method for imaging astrocytes intracortical injection two hours before 2PM. As we considered injection through the PDMS membrane to be traumatic to the investigative side, we continued performing burr holes on the contralateral side of the window, as we discovered the SR101 to spread globally across the brain. The transgenic mice expressed YFP-positive neurons for up to 28 days postoperatively.

Conclusion: Triple imaging of the single components of the NVU combined with SHG is a stable tool to image and examine delicate processes in the brain physiologically and post-stroke by means of 2 PM in vivo.