Figure 2.

Total number of hippocampal neurons expressing doublecortin + s.e. Treatment groups were free-ranging birds (n = 12), captive birds with the opportunity for memory-based cache retrieval experiences (experienced, n = 12) and captive birds deprived of memory-based cache retrieval experiences (deprived, n = 12). Free-ranging birds had more neurons expressing doublecortin than either of the captive groups (both p < 0.001). Experienced birds had more neurons expressing doublecortin than deprived birds (p = 0.038).