Fernando Nottebohm

Nottebohm, F. 1999. Neuronal replacement in the song system. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban: 525. Johannesburg: BirdLife South Africa.

The high vocal centre (HVC) of the songbird brain is involved with the acquisition and production of learned song. There is a constant replacement of neurons in the HVC of adult songbirds. This replacement shows seasonal peaks, that are preceded by peaks in cell death. Much of this replacement affects projection neurons that are part of the descending pathway for the production of learned song. The role and regulation of neuronal replacement in HVC are under intense study. New experimental procedures allow for the selective removal of specific subsets of HVC neurons, followed by an evaluation of the brain's ability to replace them. I will report on the effect of this removal and replacement on learned song. On a broader front, I will report on what is known about the production, migration and differentiation of the new cells and about the factors that may regulate these processes. This material is relevant not just to an understanding of the neurobiology of vocal learning, but may also hold clues for understanding what factors limit learning in general. Neuronal replacement in HVC is also being used to explore new approaches to brain rejuvenation and repair.