Procedures

Our laboratory routinely performs histopathological analysis of the ears of individuals who have suffered from a hearing or balance problem and have willed their temporal bones, containing the ear structures, for scientific analysis. By comparing abnormal microscopic findings in a large number of temporal bones from individuals with similar clinical findings scientists can learn the underlying anatomical abnormality responsible for a particular disability. The fusion of the temporal bone histopathology laboratory previously located at the House Ear Institute and the temporal bone laboratory at UCLA have been benefiting by the numerous cellular and molecular biological facilities available on UCLA campus.

The daily interaction with researchers from the Brain Research Institute (BRI) and neurology allows us to implemented new methods of analysis of human temporal bones including: transmission and scanning electron microscopy to see ultrastructural changes; immunohistochemistry to identify inner ear specific proteins; in situ hybridization to locate a specific RNA or DNA sequence; 3D reconstruction to explore the contours of small structures; stereology to determine volume or surface areas; use of polarized light to observe bone structure; proteomics to characterize protein expression of inner ear tissues.

As an example of the productive interaction between both laboratories we highlight our recent review published in the journal “Histochemistry and Cell Biology”, in the review summarized the current immunohistochemical protocols and methods to study the normal and pathological human inner ear (Lopez et al., 2016). Given the scarcity of tissue available and the high cost of processing the human temporal using the traditional methods we proposed alternative choices like microdissection, frozen and paraffin sectioning.

To optimize the use of invaluable celloidin embedded sections of the human inner ear our laboratory and others, have been developing methods to remove celloidin from the sections and subsequent antigen retrieval. The best process and preserved tissue is now being shared with inner ear basic researchers to corroborate their previous finding in animal models. For this we are developing immunofluorescence protocols that allow the identification of up to 3 different proteins (Lopez et al., 2016).