Morphology of neurons cultured from subdivisions of the mouse cochlear nucleus

This study was designed to characterize the dendritic organization of cochlear nucleus (CN) cells grown in primary cell culture and to assess differences among cultures grown from different regions of CN. Cultures were prepared from postnatal mice and processed using microtubule-associated protein 2 (MAP2) or γ-aminobutyric acid (GABA) immunohistochemistry. CN neurons were successfully cultured from preparations grown from either the anteroventral subdivision of the nucleus (AVCN), the posterior region [posteroventral (PVCN) and dorsal (DCN) subnuclei], or the whole CN, although the cultured neurons did not exhibit complex dendritic patterns characteristic of CN neurons in vivo. Neurons cultured from the entire nucleus exhibited an increased rate of survival compared to those cultured from either the anterior or posterior regions, although similar types of cells were observed in all preparations. The majority of cultured CN neurons were GABA-positive and had soma areas that were similar to the areas of immature GABAergic neurons measured in CN sections. Small cells (soma areas ≤60 μm²) with one to three symmetrically organized dendrites and large non-GABA-ergic cells (≥120 μm²) were also present in significant numbers. Overall, CN cultures consisted of a heterogeneous population of neurons that had less elaborate dendritic organizations than cells of corresponding size that have been described in adult animals in vivo.