Thin and open vessel windows for intra-vital fluorescence imaging of murine cochlear blood flow.
Normal microvessel structure and function in the cochlea is essential for maintaining the ionic and metabolic homeostasis required for hearing function. Abnormal cochlear microcirculation has long been considered an etiologic factor in hearing disorders. A better understanding of cochlear blood flow (CoBF) will enable more effective amelioration of hearing disorders that result from aberrant blood flow. However, establishing the direct relationship between CoBF and other cellular events in the lateral wall and response to physio-pathological stress remains a challenge due to the lack of feasible interrogation methods and difficulty in accessing the inner ear. Here we report on new methods for studying the CoBF in a mouse model using a thin or open vessel-window in combination with fluorescence intra-vital microscopy (IVM). An open vessel-window enables investigation of vascular cell biology and blood flow permeability, including pericyte (PC) contractility, bone marrow cell migration, and endothelial barrier leakage, in wild type and fluorescent protein-labeled transgenic mouse models with high spatial and temporal resolution. Alternatively, the thin vessel-window method minimizes disruption of the homeostatic balance in the lateral wall and enables study CoBF under relatively intact physiological conditions. A thin vessel-window method can also be used for time-based studies of physiological and pathological processes. Although the small size of the mouse cochlea makes surgery difficult, the methods are sufficiently developed for studying the structural and functional changes in CoBF under normal and pathological conditions.
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA. Electronic address: shix@ohsu.edu.
Xiaorui
X
Shi
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Fei
F
Zhang
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Zachary
Z
Urdang
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Min
M
Dai
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Lingling
L
Neng
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Jinhui
J
Zhang
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Songlin
S
Chen
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Sripriya
S
Ramamoorthy
Oregon Hearing Research Center, Department of Otolaryngology/Head & Neck Surgery, Oregon Health & Science University, Portland, OR, USA.
Alfred L
AL
Nuttall
D000161:Acoustic Stimulation; D000818:Animals; D001783:Blood Flow Velocity; D016026:Bone Marrow Transplantation; D002199:Capillary Permeability; D058948:Cell Tracking; D003051:Cochlea / Q000098:blood supply*; D003911:Dextrans / Q000008:administration & dosage; D016650:Fluorescein-5-isothiocyanate / Q000008:administration & dosage / Q000031:analogs & derivatives; D005456:Fluorescent Dyes / Q000008:administration & dosage; D007262:Infusions, Intravenous; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D008833:Microcirculation; D008856:Microscopy, Fluorescence / Q000379:methods*; D055806:Microvessels / Q000378:metabolism / Q000502:physiology* / Q000601:surgery; D023421:Models, Animal; D012039:Regional Blood Flow; D013997:Time Factors
D003911:Dextrans; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate