Figure 4.

Transecting both the anterior commissure (Fig. 2C) and forebrain input (including the EA:CeA plus BNST) to PB disrupts synchrony of fictive fast but not slow trills. A, Recordings from the left and right laryngeal nerves in an intact male brain. B, Enlarged views of left (blue) and right (red) nerve recordings during fictive fast and slow trills; traces from left and right nerve overlap. C, Example cross-correlation between the left and right nerve during fictive fast and slow trills calculated by a sliding a recording of a single compound action potential from one nerve over the other. Peak cross-correlation coefficients are centered around zero, indicating that the two nerves are active simultaneously. D, Bilateral forebrain and anterior commissure input to the PB were removed. Transection is indicated by a red line with scissors, transected projections by dotted arrows, and intact projections by solid arrows. E, Recordings from the left (top trace) and right (bottom trace) laryngeal nerves in an intact male brain. F, Enlarged views of left (red) and right (blue) nerve recordings during fictive fast and slow trills in a transected brain. The bottom trace shows the overlay of the left and right nerve recordings. G, A cross-correlation between the left and right nerve during fast and slow trills generated by a double-transected brain. The peak cross-correlation coefficient for slow trills is centered around zero, as in the intact brain, but for fast trills correlation coefficients are variable, indicating that the left and right laryngeal nerves are activated simultaneously during slow trills, but asynchronously during fast trills. Modified from Yamaguchi et al. (2017).