Figure 1.

Influence of spatial learning on the dendritic arbor complexity of neo-neurons generated 2 months (top) or 4 months (bottom) before learning. a, b, Experimental designs. c, d, Representative examples of 2-month-old (c) and 4-month-old (d) adult-born neurons labeled with a GFP retrovirus. Scale bar, 50 μm. Spatial learning increases the dendritic length (e, f), the number of nodes (g, h), and the size of the cell bodies (i, j) of adult-born neurons. **p ≤ 0.01 compared with age-matched control groups. C, Control (2 months: n = 6; 4 months: n = 4); L, learning (2 months: n = 8; 4 months: n = 6). Error bars indicate SEM.