Figure 6.
Ipsi-nostril obstruction rapidly enhances individual AON neuron responsiveness to contra-nasal inputs. A, Time course of the response magnitude (R.M.) of an AON neuron to ipsi-OE (red diamond) or contra-OE (blue square) odorant stimulation (upper trace). Shown are firing rates (F.R.) (1 bin = 0.3 s, middle) and spike activity (bottom) at times a, b, c, and d. This neuron responded only to ipsi-OE stimulation before ipsi-nostril obstruction (a and b), but a few minutes after ipsi-nostril obstruction (c and d) it started responding strongly to contra-OE stimulation. Filled triangle, the start of ipsi-nostril obstruction; open triangle, the time of reopening the ipsi-nostril. B, Nasal obstruction enhances responsiveness to contra-nasal inputs of AON neurons. Each row (cells 1–3) indicates a raster representation of the spike discharges of an individual AON neuron during inhalation of room air, aligned with the respiratory phase. Spike responses to room air inhalation during one respiration cycle are shown on the y-axis (from the start of inspiration (In.) to the end of expiration (Ex.)). Responses to successive inhalations are arranged on the x-axis. After ipsi-nostril obstruction (at time 0, filled triangle), the respiration phase-locked discharges of all three neurons (which peaked at the inspiration–expiration transition) disappeared, but then reappeared ∼300 s later (filled diamond) with a peak at the expiration phase. Open triangle, the time of reopening the ipsi-nostril.