Expression of Oligodendrocyte Marker during Peripheral-Central Transitional Zone Formation of the Postnatal Mouse Cochlear Nerve

Abstract

Objective

To better understand oligodendrocyte protein expression along the mouse cochlear nerve in postnatal mice.

Study Design

In vivo murine study.

Setting

Research laboratory.

Subjects and Methods

Swiss Webster mice used at multiple postnatal days (0, 1, 3, 5, 7, 8, 10, 14, 30, and 60). There were 5 replicates at each postnatal day. Cryosection was done to produce sections that included the cochlear nucleus, cochlear nerve, and cochlea in a single sample. Differential interference contrast (DIC) microscopy and immunofluorescence with antibodies specific to the oligodendrocyte protein Olig2 were used to study the cochlear nerve of Swiss Webster mice at postnatal days.

Results

The myelination of central nervous system projections initiates in close proximity to the peripheral nervous system–central nervous system transitional zone (PCTZ), and oligodendrocytes in neonatal mice are seen with immunohistochemistry peripheral to the DIC-PCTZ interface.

Conclusions

As the PCTZ migrates from the brain to the cochlea, oligodendrocytes are a part of peripheral extension of central nervous system tissue along the cochlear nerve. Expression of oligodendrocyte marker Oligo2 was observed peripherally to the formation of PCTZ, as determined by DIC microscopy.