Exposure to a broad range of odorants decreases cell mortality in the olfactory bulb

Experience with multiple odorants during early postnatal development increases the number of cells in the olfactory bulb of rats. In this study, we asked whether at least part of this increase was due to decreased cell death. We selected 30 natural odorants or synthetic odorant mixtures to stimulate a broad area of the bulb during postnatal days 1–15, and counted the number of cells with DNA damage associated with cell death in both the glomerular and the granule cell layers of the main olfactory bulb. Early olfactory enrichment significantly decreased cell death in both bulbar laminae. Thus, olfactory enrichment can spare bulbar cells during early development, possibly leading to increased efficacy in bulb function and enhanced bulbar responses.

[1]  M. Leon,et al.  Enhanced neural response to familiar olfactory cues. , 1984, Science.

[2]  B. Winblad,et al.  Effects of environmental enrichment on cognitive function and hippocampal NGF in the non-handled rats , 1999, Behavioural Brain Research.

[3]  L. Maffei,et al.  Behavioral / Systems / Cognitive Acceleration of Visual System Development by Environmental Enrichment , 2004 .

[4]  C. Strambi,et al.  Influence of environmental stimulation on neurogenesis in the adult insect brain. , 2000, Journal of neurobiology.

[5]  L. Maffei,et al.  Enriched environment and acceleration of visual system development , 2004, Neuropharmacology.

[6]  E. Alleva,et al.  Epigenetic control of neurobehavioural plasticity: the role of neurotrophins , 2004, Behavioural pharmacology.

[7]  M. Kilgard,et al.  Environmental enrichment improves response strength, threshold, selectivity, and latency of auditory cortex neurons. , 2004, Journal of Neurophysiology.

[8]  D A Wilson,et al.  Spatial patterns of olfactory bulb single-unit responses to learned olfactory cues in young rats. , 1988, Journal of neurophysiology.

[9]  B. Fiske,et al.  Cell death in the developing and sensory‐deprived rat olfactory bulb , 2001, The Journal of comparative neurology.

[10]  Timothy A Mousseau,et al.  Female mating bias results in conflicting sex-specific offspring fitness , 2004, Nature.

[11]  S. O’Mara,et al.  Impact of enriched-environment housing on brain-derived neurotrophic factor and on cognitive performance after a transient global ischemia , 2004, Behavioural Brain Research.

[12]  S. Ben‐Sasson,et al.  Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation , 1992, The Journal of cell biology.

[13]  R. Sandeman,et al.  "Impoverished" and "enriched" living conditions influence the proliferation and survival of neurons in crayfish brain. , 2000, Journal of neurobiology.

[14]  M. Leon,et al.  Spatial distribution of [14C]2‐deoxyglucose uptake in the glomerular layer of the rat olfactory bulb following early odor preference learning , 1996, The Journal of comparative neurology.

[15]  Michael Leon,et al.  Olfactory experience modulated apoptosis in the developing olfactory bulb. , 1995, Brain research.

[16]  L. Rosselli-Austin,et al.  Enriched neonatal odor exposure leads to increased numbers of olfactory bulb mitral and granule cells. , 1990, Brain research. Developmental brain research.

[17]  M. Leon,et al.  Increase in a focal population of juxtaglomerular cells in the olfactory bulb associated with early learning , 1991, The Journal of comparative neurology.

[18]  Christelle Rochefort,et al.  Enriched Odor Exposure Increases the Number of Newborn Neurons in the Adult Olfactory Bulb and Improves Odor Memory , 2002, The Journal of Neuroscience.

[19]  Christelle Rochefort,et al.  Short‐term survival of newborn neurons in the adult olfactory bulb after exposure to a complex odor environment , 2005, The European journal of neuroscience.

[20]  Short‐lasting exposure to one odour decreases general reactivity in the olfactory bulb of adult rats , 1998, The European journal of neuroscience.

[21]  M. Leon,et al.  Odor specificity of the enhanced neural response following early odor experience in rats. , 1986, Brain research.

[22]  Michael Leon,et al.  A learned odor evokes an enhanced Fos-like glomerular response in the olfactory bulb of young rats , 1995, Brain Research.