Importance of newly generated neurons in the adult olfactory bulb for odor discrimination
AUTOR(ES)
Gheusi, Gilles
FONTE
The National Academy of Sciences
RESUMO
In adult rodents, neurons are continually generated in the subventricular zone of the forebrain, from where they migrate tangentially toward the olfactory bulb, the only known target for these neuronal precursors. Within the main olfactory bulb, they ascend radially into the granule and periglomerular cell layers, where they differentiate mainly into local interneurons. The functional consequences of this permanent generation and integration of new neurons into existing circuits are unknown. To address this question, we used neural cell adhesion molecule-deficient mice that have documented deficits in the migration of olfactory-bulb neuron precursors, leading to about 40% size reduction of this structure. Our anatomical study reveals that this reduction is restricted to the granule cell layer, a structure that contains exclusively γ-aminobutyric acid (GABA)ergic interneurons. Furthermore, mutant mice were subjected to experiments designed to examine the behavioral consequences of such anatomical alteration. We found that the specific reduction in the newly generated interneuron population resulted in an impairment of discrimination between odors. In contrast, both the detection thresholds for odors and short-term olfactory memory were unaltered, demonstrating that a critical number of bulbar granule cells is crucial only for odor discrimination but not for general olfactory functions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=26520Documentos Relacionados
- Assessment and discrimination of odor stimuli in rat olfactory bulb by dynamic functional MRI
- Nicotinic receptors regulate the survival of newborn neurons in the adult olfactory bulb
- Newly generated neurons in the amygdala and adjoining cortex of adult primates
- Refinement of odor molecule tuning by dendrodendritic synaptic inhibition in the olfactory bulb.
- Odor-induced increases in c-fos mRNA expression reveal an anatomical "unit" for odor processing in olfactory bulb.