High-density cortical µECoG arrays concurrently track spreading depolarizations and long-term evolution of stroke in awake rats

• Published in: Communications biology Vol. 7; no. 1; pp. 263 - 15
• Main Authors: Palopoli-Trojani, Kay, Trumpis, Michael, Chiang, Chia-Han, Wang, Charles, Williams, Ashley J., Evans, Cody L., Turner, Dennis A., Viventi, Jonathan, Hoffmann, Ulrike
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04.03.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/378/1689; 692/699/375/534; Animals; Biomedical and Life Sciences; Blood flow; Boundaries; Electrocorticography; Electrodes; Evolution; Homeostasis; Humans; Infarction; Ischemia; Ischemic Stroke; Life Sciences; Rats; Spreading depression; Stroke; Wakefulness
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-024-05932-0

Spreading depolarizations (SDs) are widely recognized as a major contributor to the progression of tissue damage from ischemic stroke even if blood flow can be restored. They are characterized by negative intracortical waveforms of up to -20 mV, propagation velocities of 3 - 6 mm/min, and massive disturbance of membrane ion homeostasis. High-density, micro-electrocorticographic (μECoG) epidural electrodes and custom, DC-coupled, multiplexed amplifiers, were used to continuously characterize and monitor SD and µECoG cortical signal evolution in awake, moving rats over days. This highly innovative approach can define these events over a large brain surface area (~ 3.4 × 3.4 mm), extending across the boundaries of the stroke, and offers sufficient electrode density (60 contacts total per array for a density of 5.7 electrodes / mm 2 ) to measure and determine the origin of SDs in relation to the infarct boundaries. In addition, spontaneous ECoG activity can simultaneously be detected to further define cortical infarct regions. This technology allows us to understand dynamic stroke evolution and provides immediate cortical functional activity over days. Further translational development of this approach may facilitate improved treatment options for acute stroke patients. High-density μECoG metal electrodes and multiplexed amplifiers are developed for DC-coupled cortical recordings, which are used to continuously characterize and monitor SD and spontaneous μECoG evolution in awake, moving rats over days.