TY - JOUR
T1 - Mechanosensory-Based Phase Coding of Odor Identity in the Olfactory Bulb
AU - Iwata, Ryo
AU - Kiyonari, Hiroshi
AU - Imai, Takeshi
PY - 2017/12/6
Y1 - 2017/12/6
N2 - 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 these temporal patterns are generated and how they are 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. We propose that phase, not rate, coding is a robust encoding strategy of odor identity and is ensured by airflow-induced mechanosensation in OSNs. Iwata et al. demonstrate that phase coding, but not rate coding, in mitral cells is useful for concentration-invariant odor identity coding. They also found that mechanosensation in olfactory sensory neurons facilitates, rather than masks, the robust phase coding of odors.
AB - 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 these temporal patterns are generated and how they are 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. We propose that phase, not rate, coding is a robust encoding strategy of odor identity and is ensured by airflow-induced mechanosensation in OSNs. Iwata et al. demonstrate that phase coding, but not rate coding, in mitral cells is useful for concentration-invariant odor identity coding. They also found that mechanosensation in olfactory sensory neurons facilitates, rather than masks, the robust phase coding of odors.
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U2 - 10.1016/j.neuron.2017.11.008
DO - 10.1016/j.neuron.2017.11.008
M3 - Article
C2 - 29216451
AN - SCOPUS:85037364278
VL - 96
SP - 1139-1152.e7
JO - Neuron
JF - Neuron
SN - 0896-6273
IS - 5
ER -