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. Author manuscript; available in PMC: 2017 Mar 20.
Published in final edited form as: Neuron. 2016 Mar 31;90(2):374–387. doi: 10.1016/j.neuron.2016.03.007

Figure 5. Conditional activation of facial motoneurons during sniffing in head-restrained rats.

Figure 5

(A,B) Discharges of respiratory motoneurons during basal respiration and sniffing. Note that in these two examples sniffing occurs without significant whisking. (C) Phase plots of motoneuronal discharges across a population of five inspiratory motoneurons (solid line; 572 inspirations), and 7 expiratory motoneurons (dashed line; 974 expirations). (D) The recording site of the neuron shown in (B) was labeled with a deposit of Chicago sky blue. (E) EMG recording of nasolabialis motor units during basal respiration and sniffing. Note that muscle nasolabialis preferentially contracts in phase with expiration during sniffing. (F) Phase plots of muscle nasolabialis motor units activity during basal respiration (< 4Hz; 1180 breaths) and sniffing (> 4Hz; 1725 sniffs). Note the stronger modulation during sniffing, and the phase shift of activity between basal respiration and sniffing. (G) EMG recording of nasolabialis profundus motor units during basal respiration and sniffing. Note that the small unit is active during both basal respiration and sniffing, while the large unit is active during sniffing. (H) Phase plots of muscle nasolabialis motor units activity during basal respiration (< 4Hz; 668 breaths) and sniffing (> 4Hz; 756 sniffs). Note the stronger modulation during the inspiratory phase of sniffing.