Figure 2.

Phase contrast photomicrographs illustrating the maturation of young adult hippocampal neurons cultured with or without HUCB cells. A) Cultures of hippocampal neurons in the non-treated, Media group had few surviving cells and sparse, short processes after 14 DIV. B) While neurons in the non-treated culture had spread across the culture dish at 21 DIV, the dendrites were still short and an extensive network of intercellular connections had not yet formed. C) Even after 28 DIV, hippocampal neurons grown in culture without HUCB, remained predominantly clustered together and had simple, short neuritic processes. D) In contrast, hippocampal neurons co-cultured with HUCB cells even for as little as 14 DIV exhibited normal, healthy neuronal morphology with multiple, long processes (dendritic arbors) which interconnected with each other and formed networks. E) After 21 DIV, the HUCB treated adult hippocampal neurons exhibited even more extensive dendritic arborization, similar in morphology to sympathetic neurons. F) After 28 DIV, the HUCB treated hippocampal neurons formed extremely complex tree-like dendritic structures. G) Many of the hippocampal cells expressed the mature neuronal marker, MAP2 regardless of whether they were treated with HUCB. Consistent with the phase contrast images in A–F, MAP2 immuno-labeling further demonstrated the development of an extensive dendritic tree over time. Fluorescent photomicrographs taken after 21 DIV of G) hippocampal neurons grown in Media alone and H) hippocampal neurons co-cultured with HUCB cells. Scale bar = 50 μm.