Second harmonic generation microscopy of otoconia

Kennedy Brittain; MacAulay Harvey; Richard Cisek; Saranyan Pillai; Sean D Christie; Danielle Tokarz

doi:10.1364/BOE.457967

Second harmonic generation microscopy of otoconia

Biomed Opt Express. 2022 May 26;13(6):3593-3600. doi: 10.1364/BOE.457967. eCollection 2022 Jun 1.

Authors

Kennedy Brittain^{1

2}, MacAulay Harvey¹, Richard Cisek¹, Saranyan Pillai³, Sean D Christie³, Danielle Tokarz¹

Affiliations

¹ Department of Chemistry, Saint Mary's University, 923 Robie Street, Halifax, Nova Scotia, B3H 3C3, Canada.
² Department of Medical Neuroscience, Dalhousie University, 5850 College Street, PO Box 15000, Halifax, Nova Scotia, B3H 4R2, Canada.
³ Department of Surgery (Neurosurgery), Dalhousie University, #3814-1796 Summer Street, Halifax, Nova Scotia, B3H 3A7, Canada.

Abstract

The origin of second harmonic generation (SHG) signal in otoconia was investigated. SHG signal intensity from otoconia was compared to pure calcite crystals, given calcite is the primary component of otoconia and is known to emit surface SHG. The SHG intensity from calcite was found to be ∼41× weaker than the SHG intensity from otoconia signifying that the SHG signal from otoconia is likely generated from the organic matrix. Furthermore, the SHG intensity from otoconia increased when treated with a chelating agent known to dissolve calcite which confirms that calcite is not the source of SHG. Additionally, polarization-resolved SHG microscopy imaging revealed that the arrangement of the SHG emitters is radial and can form highly ordered domains.