Figure 2.

The pre-existing population of interneurons is unaffected by the AraC treatment. A, Immunostaining for the neuronal marker NeuN in the different regions of the OB derived from control (NaCl) and AraC-treated animals. Scale bar, 50 μm. B, NeuN⁺ cell density quantification in the dorsal, lateral, medial, and ventral OB regions. Data are presented as mean ± SEM (n = 4 animals per group). C, Top, Confocal images of GFP⁺ granule cells revealing their complete morphology. These cells were labeled with an injection of GFP-encoding lentivirus in the rostral migratory stream 28 d before the NaCl or AraC treatment. Bottom, Higher magnification of boxed regions showing the spine density of the adult-generated granule cells. Scale bars, 20 μm. D, No changes in the primary dendrite length (calculated as the length of the dendrite from the soma to the first point of ramification) or the total dendritic length (excluding the primary dendrite) were observed in GFP⁺ cells between the control and neurogenesis-ablated OBs. Data are presented as mean ± SEM (n = 31 and 27 cells for control and AraC-treated groups, respectively). E, Spine density quantification of GFP⁺ cells generated in adulthood. Each point represents the spine density of individual cell, whereas horizontal bars represent the mean values for NaCl and AraC treatments.