Tubercle units respond to an auditory stimulus. a, Representative traces showing multiunit activity, LFP (0–100 Hz second-order low-pass filter), and respiration over the course of 4 s. Inhalation in respiratory trace is an upward deflection. Time of tone presentation is indicated by the shaded gray box. b, Spike raster plot and peristimulus time histogram from a single unit throughout multiple presentations of an auditory tone. The top halves of each panel show spike activity as raster plots (dots) of the unit in response to the tone across multiple trials (y-axis; each row is a single trial). Summarizing the raster plot is a peristimulus time histogram with average firing rate (in hertz) on the y-axis. Histogram, 100 ms time bins. c, Bar graph and scatter plot showing average “pre” (2 s prestim) and tone evoked (tone icon; 2 s during stim) responses of five tubercle units that all showed significant spike rate increases in response to tone. *p < 0.05, two-tailed t test. d, LFP power spectrograms of pretone (2 s prestim) and tone (2 s during tone) LFP activity. Data are from four mice, five tone trials each.