Research Methodologies for Adult Neurogenesis

The first works in neurogenesis were based on anatomical and morphological descriptions of the mitotic figures that were either found randomly within the brain or concentrated in definite regions. The emergence of electron microscopy (EM), which enabled greater magnifications, implied a significant gain of knowledge compared to the information obtained with light microscopy (LM). However, the exclusive use of EM or LM to study proliferation did not prove the existence of neurogenesis. It was necessary to combine morphology with immunohistochemistry, cell culture, electrophysiology, and molecular genetics to finally demonstrate that new cells were born in the adult brain and that these cells were able to become functional afterwards. In vitro technologies enable the growth, amplification and isolation of cells in terms of their immunochemical pattern and morphology by using flow cytometry. In addition, the use of transgenic animals to amplify or knock out target genes conditionally or permanently is highly significant for studies of the functions of gene products. Here, we briefly list and describe some of the methods currently used to analyze adult neurogenesis.