Figure 1. Olfactory receptor neuron action potential generation depends on frequency of stimulation.

An isolated olfactory receptor neuron was stimulated repeatedly 30 times with the odorant cineole for 100 ms as indicated by the solution monitor at the top. The response was recorded using the suction pipette technique. The interstimulation interval was either 400 or 100 ms, which gave stimulation frequencies of 2 Hz (A and C) or 5 Hz (B and D), respectively. Cineole concentrations were 30 μm (A and B) or 100 μm (C and D) as noted next to each recording. All recordings from the same neuron.