Optogenetic Spreading Depolarizations Do Not Worsen Acute Ischemic Stroke Outcome

BACKGROUND: Spreading depolarizations (SDs) are believed to contribute to injury progression and worsen outcomes in focal cerebral ischemia because exogenously induced SDs have been associated with enlarged infarct volumes. However, previous studies used highly invasive methods to trigger SDs that can directly cause tissue injury (eg, topical KCl) and confound the interpretation. Here, we tested whether SDs indeed enlarge infarcts when induced via a novel, noninjurious method using optogenetics.

METHODS: Using transgenic mice expressing channelrhodopsin-2 in neurons (Thy1-ChR2-YFP), we induced 8 optogenetic SDs to trigger SDs noninvasively at a remote cortical location in a noninjurious manner during 1-hour distal microvascular clip or proximal an endovascular filament occlusion of the middle cerebral artery. Laser speckle imaging was used to monitor cerebral blood flow. Infarct volumes were then quantified at 24 or 48 hours.

RESULTS: Infarct volumes in the optogenetic SD arm did not differ from the control arm in either distal or proximal middle cerebral artery occlusion, despite a 6-fold and 4-fold higher number of SDs, respectively. Identical optogenetic illumination in wild-type mice did not affect the infarct volume. Full-field laser speckle imaging showed that optogenetic stimulation did not affect the perfusion in the peri-infarct cortex.

CONCLUSIONS: Altogether, these data show that SDs induced noninvasively using optogenetics do not worsen tissue outcomes. Our findings compel a careful reexamination of the notion that SDs are causally linked to infarct expansion.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:54

Enthalten in:

Stroke - 54(2023), 4 vom: 01. Apr., Seite 1110-1119

Sprache:

Englisch

Beteiligte Personen:

Sugimoto, Kazutaka [VerfasserIn]
Yang, Joanna [VerfasserIn]
Fischer, Paul [VerfasserIn]
Takizawa, Tsubasa [VerfasserIn]
Mulder, Inge A [VerfasserIn]
Qin, Tao [VerfasserIn]
Erdogan, Taylan D [VerfasserIn]
Yaseen, Mohammad A [VerfasserIn]
Sakadžić, Sava [VerfasserIn]
Chung, David Y [VerfasserIn]
Ayata, Cenk [VerfasserIn]

Links:

Volltext

Themen:

Channelrhodopsins
Infarction
Ischemic stroke
Journal Article
Middle cerebral artery
Optogenetics
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 29.03.2023

Date Revised 02.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1161/STROKEAHA.122.041351

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM353823449