When an olfactory nerve fires twice in quick succession, the second signal is dampened by about 40% for nearly half a second due to feedback signals from nearby brain cells that activate GABA_B receptors on the nerve endings, reducing calcium entry and neurotransmitter release.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Whether paired-pulse suppression of olfactory input with similar kinetics is a conserved feature across vertebrate species and contributes to temporal coding of odorants.
A systematic review and meta-analysis of all studies measuring paired-pulse ratios in olfactory receptor neuron terminals across species (mice, rats, turtles, humans post-mortem), using standardized interstimulus intervals (10–2000 ms), dye types, and recording conditions to quantify suppression magnitude and recovery kinetics.
Whether pharmacologically blocking GABA_B receptors in vivo alters the temporal dynamics of odor-evoked neural responses in the olfactory bulb.
A double-blind, randomized, crossover trial in 20 adult mice, receiving intranasal CGP55845 (100 μM) or vehicle, with in vivo two-photon calcium imaging of glomerular responses to paired odor pulses delivered at 400-ms intervals, measuring suppression ratio and recovery time as primary outcomes.
Whether the degree of paired-pulse suppression in olfactory neurons correlates with individual differences in odor discrimination speed or accuracy over time.
A longitudinal cohort study of 100 healthy adults, measuring olfactory paired-pulse suppression via EEG or fMRI adaptation paradigms at baseline and annually over 3 years, correlating suppression magnitude with performance on standardized odor discrimination tasks.
Whether individuals with impaired odor discrimination show reduced paired-pulse suppression in olfactory bulb circuits compared to controls.
A case-control study comparing paired-pulse suppression ratios in 30 individuals with congenital or acquired anosmia and 30 age-matched controls using fMRI adaptation paradigms to measure glomerular response attenuation to paired odor pulses at 400-ms intervals.
Whether paired-pulse suppression of calcium influx in mouse olfactory bulb slices varies across glomeruli or odorant-specific pathways.
A cross-sectional analysis of 50 glomeruli in 15 mouse olfactory bulb slices, measuring paired-pulse suppression ratios (400-ms ISI) using calcium imaging in response to electrical stimulation, and correlating suppression magnitude with glomerular location and odorant receptor expression profile.