Three‐Dimensional Anatomy of the Temporal Bone in Normal Mice

Abstract

This study was performed to determine the three-dimensional (3D) structure of the murine temporal bone and to provide a survey atlas of the temporal bone structures in mice. The temporal bones of adult BALB/c mice were examined and 3D high-resolution reconstructions of the temporal bone were obtained using a micro-CT system. Using the system described here, the bony labyrinth and membranous labyrinth could be investigated in a non-destructive manner. The turning rate of the cochlea was two (human rate: two and a half). The shapes of the superior and posterior semicircular canals were more flexed than those in humans. The malleus manubrium was directed anteriorly and was thin and fan-shaped like a Persian sword. The size of the incus relative to the malleus was smaller than that in the human ossicles. The 3D reconstruction of murine temporal bone described in this study provides anatomical information that will be useful in future studies using mouse model.

Sound transmission along the ossicular chain in common wild-type laboratory mice

“…Past studies on the mouse middle ear showed its specific morphology and motion (Fleischer, 1978; Lee et al, 2009; Qin et al, 2010; Rosowski et al, 2003; Saunders and Summers, 1982). However, sound transmission along the mouse ossicular chain is still not well understood.…”

Applicability of vital staining and tissue clearing to vascular anatomy and melanocytes' evaluation of temporal bone in six laboratory species

“…Before the tissue clearing, each vital‐stained middle ear was examined. A Persian sword‐like malleus handle was seen in the KWM, mouse, hamster and gerbil (Figure a–e; Lee et al, ). In the gerbil and hamster, tiny fibrotic dense tissue was shown in the central portion ( umbo ) of the tympanic membrane (Figure c,e), similar to humans.…”

“…Most morphological analyses use 2‐dimensional images created through histological methods, even though 3‐dimensional techniques exist. For examples, micro CT, scanning Thin‐Sheet Laser Imaging Microscopy, optical micro‐angiography, optical coherence tomography and scanning laser optical tomography have all been tried as 3‐dimensional tools to understand the anatomy and demonstrate the relationship among the various structures (Buytaert, Johnson, Dierick, Salih, & Santi, ; Choudhury, Chen, Shi, Nuttall, & Wang, ; Lee et al, ; Lee, Park, Kang, & Choung, ; Tinne et al, ; Zou et al, ). Unfortunately, these, computer‐assisted reconstructed images have provided limited information when trying to study the in vivo anatomy.…”

“…The cochlea is vulnerable to ischaemia because it is an end organ, supplied by only a few branches of the internal auditory artery (Axelsson, ; Kim et al, ; Perlman, Kimura, & Fernandez, ). The rodent labyrinth differs from the human in terms of its number of cochlea turns (Lee et al, ) and its prominent stapedial artery. The cochlea and vestibule in some mammals contain macrophage‐like melanocytes (Zhang, Zhang, Neng, & Shi, ).…”

Dissection of the Auditory Bulla in Postnatal Mice: Isolation of the Middle Ear Bones and Histological Analysis

“…A medial view of the right auditory ossicles isolated from a P31 mouse shows typical features of the mouse malleus, namely, the "gliding-seagullwing-like" (or Persian sword-like 45 ) manubrium, a prominent processus brevis (orbicular apophysis, see Discussion), and the transversal lamina (Figure 6). Note that the anterior process (processus anterior) was fractured in the dissection procedure around the goniale and was separated from the tympanic ring (ectotympanic).…”