Original Research ARTICLE

Front. Neurosci., 16 November 2009 | http://dx.doi.org/10.3389/neuro.22.003.2009

Ablation of mouse adult neurogenesis alters olfactory bulb structure and olfactory fear conditioning

1
Department of Biological Sciences, Columbia University, New York, NY, USA
2
Weill Medical College of Cornell University, Burke Medical Research Institute, White Plains, NY, USA
Adult neurogenesis replenishes olfactory bulb (OB) interneurons throughout the life of most mammals, yet during this constant flux it remains unclear how the OB maintains a constant structure and function. In the mouse OB, we investigated the dynamics of turnover and its impact on olfactory function by ablating adult neurogenesis with an x-ray lesion to the sub-ventricular zone (SVZ). Regardless of the magnitude of the lesion to the SVZ, we found no change in the survival of young adult born granule cells (GCs) born after the lesion, and a gradual decrease in the population of GCs born before the lesion. After a lesion producing a 96% reduction of incoming adult born GCs to the OB, we found a diminished behavioral fear response to conditioned odor cues but not to audio cues. Interestingly, despite this behavioral deficit and gradual anatomical changes, we found no electrophysiological changes in the GC population assayed in vivo through dendro-dendritic synaptic plasticity and odor-evoked local field potential oscillations. These data indicate that turnover in the granule cell layer is generally decoupled from the rate of adult neurogenesis, and that OB adult neurogenesis plays a role in a wide behavioral system extending beyond the OB.
Keywords:
granule cell, sub-ventricular zone, irradiation, amygdala, freezing, dendro-dendritic, survival, plasticity
Citation:
Valley MT, Mullen TR, Schultz LC, Sagdullaev BT and Firestein S (2009). Ablation of mouse adult neurogenesis alters olfactory bulb structure and olfactory fear conditioning. Front. Neurosci. 3:51. doi: 10.3389/neuro.22.003.2009
Received:
21 September 2009;
 Paper pending published:
18 October 2009;
Accepted:
28 October 2009;
 Published online:
16 November 2009.

Edited by:

Pierre M. Lledo, Pasteur Institute, France

Reviewed by:

Luca Bonfanti, University of Turin, Italy
Pierre M. Lledo, Pasteur Institute, France
Copyright:
© 2009 Valley, Mullen, Schultz, Sagdullaev and Firestein. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence:
Stuart Firestein, Department of Biological Sciences, 600 Fairchild, Columbia University, New York, NY, 10027, USA. e-mail: sjf24@columbia.edu