Imaging the intact guinea pig tympanic bulla by orthogonal-plane fluorescence optical sectioning microscopy

Orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy was developed for the purpose of making quantitative measurements of the intact mammalian cochlea and to facilitate 3D reconstructions of complex features. A new version of this imaging apparatus was built with a specimen chamber designed to accommodate samples as large as the intact guinea pig bulla. This method left the cochlear connections with the vestibular system and with the ossicles of the middle ear undisturbed, providing views within the cochlea with no breaches of its structural integrity. Since the features within the bulla were not physically touched during the preparation process, the risk of damage was minimized, and were imaged in relatively pristine condition with spatial resolution to 16 μm. A description of the imaging method and specimen preparation procedure is presented, as are images of features from the cochlea, ossicles, and vestibular system.