title: Longitudinal vascular dynamics following cranial window and electrode implantation measured with speckle variance optical coherence angiography.
abstract: Speckle variance optical coherence angiography (OCA) was used to characterize the vascular tissue response from craniotomy, window implantation, and electrode insertion in mouse motor cortex. We observed initial vasodilation ~40% greater than original diameter 2-3 days post-surgery (dps). After 4 weeks, dilation subsided in large vessels (>50 µm diameter) but persisted in smaller vessels (25-50 µm diameter). Neovascularization began 8-12 dps and vessel migration continued throughout the study. Vasodilation and neovascularization were primarily associated with craniotomy and window implantation rather than electrode insertion. Initial evidence of capillary re-mapping in the region surrounding the implanted electrode was manifest in OCA image dissimilarity. Further investigation, including higher resolution imaging, is required to validate the finding. Spontaneous lesions also occurred in many electrode animals, though the inception point appeared random and not directly associated with electrode insertion. OCA allows high resolution, label-free in vivo visualization of neurovascular tissue, which may help determine any biological contribution to chronic electrode signal degradation. Vascular and flow-based biomarkers can aid development of novel neural prostheses.
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring MD 20993, USA.
authors.forename: Daniel X
authors.initials: DX
authors.lastname: Hammer
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring MD 20993, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Lozzi
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring MD 20993, USA.
authors.forename: Erkinay
authors.initials: E
authors.lastname: Abliz
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring MD 20993, USA.
authors.forename: Noah
authors.initials: N
authors.lastname: Greenbaum
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring MD 20993, USA.
authors.forename: Anant
authors.initials: A
authors.lastname: Agrawal
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring MD 20993, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Krauthamer
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring MD 20993, USA.
authors.forename: Cristin G
authors.initials: CG
authors.lastname: Welle
keywords: (110.4500) Optical coherence tomography; (170.1470) Blood or tissue constituent monitoring; (170.3880) Medical and biological imaging; (170.6900) Three-dimensional microscopy