Figure 4.

Baseline firing frequency and location of dorsolateral pontine units. A: summary of firing frequency of dorsolateral pontine single units at baseline. Data are grouped by class (inspiratory or expiratory) (left) or inspiratory subgroup (right). Symbols represent the average peak firing frequency over 10 consecutive breaths for individual units. Line and error are means ± SE. **P < 0.01, ***P < 0.001 by unpaired t test (left) or one-way ANOVA and Tukey’s post hoc test (right). Symbols are keyed for subclass (see results). Symbol outline represents if the unit had activity during only respiration (respiratory, black) or had activity during respiration and “swallowing” (multifunctional, neon green). B: semi-schematic drawings of coronal slices through rat dorsolateral pons. Location of recorded units was identified post hoc in coronal slices (n = 42 rats). A7, noradrenergic neurons; E-dec, expiratory decrementing; E-plat, expiratory plateau; EIPS, expiratory/inspiratory phase-spanning; I-aug, inspiratory augmenting; I-dec, inspiratory decrementing; I-plat, inspiratory plateau; IC, inferior colliculus; IEPS, inspiratory/expiratory phase-spanning; KF, Kölliker–Fuse; LPB, lateral parabrachial area; mcp, middle cerebellar peduncle; MPB, medial parabrachial area; pre-I/I, preinspiratory/inspiratory; SCP, superior cerebellar peduncle; TRM1, tonic respiratory modulated expressing decreased activity during postinspiration; TRM2, tonic respiratory modulated expressing an increase in activity at inspiratory/expiratory phase transition; 4V, fourth ventricle.