FIG. 4.

Local BIC and PTX application alters the temporal organization of song-induced spikes in NCM. A: raw traces depicting multiunit responses to song playback from representative electrodes located in control and experimental hemispheres prior to drug application. Note that responses are sustained throughout the duration of the stimulus in both hemispheres. NCM typically has a high level of irregular spontaneous activity that can be seen preceding the stimulus. Song syllables can vary widely in amplitude, as seen on the stimulus envelope traces. B: application of BIC in the experimental hemisphere drastically changes the response profile of song-activated units. Note that the response becomes highly phasic and synchronized, particularly in relation to the 1st syllable, and that sustained activity between syllables is largely abolished. C: PTX treatment induces changes similar to those observed with BIC.