Circuit mechanisms for the temporal coding in the olfactory bulb

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H05572
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Neurophysiology / General neuroscience
• Research Institution: Kyushu University (2016-2017); Institute of Physical and Chemical Research (2015)
• Principal Investigator: Imai Takeshi 九州大学, 医学研究院, 教授 (70509851)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 感覚情報処理 / 嗅覚 / 匂い / 時間コーディング / 発火タイミング

Outline of Final Research Achievements

Mitral and tufted (M/T) cells in the olfactory bulb produce rich temporal patterns of activity in response to different odors. However, it remains unknown how they are generated and utilized in olfaction. Here we show that temporal patterning effectively discriminates between the two sensory modalities detected by olfactory sensory neurons (OSNs): odor and airflow-driven mechanical signals. Sniff-induced mechanosensation generates glomerulus-specific oscillatory activity in M/T cells, whose phase was invariant across airflow speed. In contrast, odor stimulation caused phase shifts (phase coding). We also found that odor-evoked phase shifts are concentration invariant and stable across multiple sniff cycles, contrary to the labile nature of rate coding. The loss of oscillatory mechanosensation impaired the precision and stability of phase coding, demonstrating its role in olfaction. Thus, airflow-induced mechanosensation in OSNs is important for phase coding of odor identity.

Free Research Field

神経科学