It is well known that the olfactory epithelium can adapt in the very short term to odorant stimulation by receptor desensitization and habituation. However, the ability of odorants to stimulate long-lasting changes in OSNs has been suggested but not clearly elucidated. Dr. Daniel R. Storm and colleagues from The University of Washington in Seattle developed a novel method to monitor the survival of OSNs after stimulation with odorants and to examine the signaling pathways required for cell survival. OSNs were labeled using a sophisticated noninvasive adenovirus technique. Exposure to odorants enhanced the survival of subpopulations of unperturbed neurons and neurons that were exposed to a stimulus that normally causes cell death. Further investigation revealed that the ERK/MAP kinase/CREB pathway is directly involved in odorant-stimulated rescue of OSNs.
The researchers conclude that OSNs are capable of dynamic long-term adjustment to sensory information in the environment. This is significant for animals because the persistence of odorant-detecting cells would be dictated by odorants encountered in the environment, some of which might be critical for survival. These results are also important for humans. "The identification of a chemical pathway that protects olfactory sensory neurons from cell death has important medical implications since olfactory sensory neurons die during a number of conditions including sinusitis and head injury. In addition, we lose about 1% of our sense of sm
Contact: Heidi Hardman