Perception of sniff phase in mouse olfaction.

Area of Science:

• Neuroscience
• Sensory Systems
• Olfaction

Background:

• Mammalian olfactory systems encode odors based on neuronal activation patterns and timing.
• Neuronal activity timing relative to sampling behavior is crucial in various neural systems.
• Evidence for the olfactory system's use of timing cues relative to sniffing was lacking.

Purpose of the Study:

• To investigate whether mice can perceive the timing of olfactory activation within the sniff cycle (sniff phase).
• To determine if temporal patterns of olfactory input are utilized by the mammalian olfactory system.

Main Methods:

• Utilized optogenetics in gene-targeted mice to deliver spatially constant, temporally controlled olfactory input.
• Assessed behavioral discrimination of light-evoked olfactory sensory neuron activation based on sniff phase.
• Performed electrophysiological recordings in the olfactory bulb of awake mice.

Main Results:

• Mice behaviorally reported the sniff phase of optogenetically induced olfactory sensory neuron activation.
• Discrimination of inputs shifted by as little as 10 milliseconds within the sniff cycle was achieved.
• Olfactory bulb neurons encoded photoactivation timing relative to the sniff, affecting response timing and amplitude.

Conclusions:

• The mammalian olfactory system possesses the capability to interpret temporal patterns of neural activity.
• Timing of olfactory activation relative to sampling behavior (sniff phase) is a significant cue for rapid and accurate odor perception.