OT neurons display divergent responses to conditioned odors. A, B, Time course of odor-evoked changes in firing rate relative to baseline as indicated by auROC in response to rewarded (A) and unrewarded (B) odors. Each row represents one single neuron, and neurons are sorted by baseline rates during rewarded odor trials (top row = lowest rate; n = 190 neurons). C, Population average auROC values for all task-responsive neurons (n = 165 neurons) in response to rewarded and unrewarded odors. An early divergence in auROC values occurred before the average behavioral response, with values >0.5 persisting for a longer duration in response to the rewarded odor. A transient increase in auROC coincided with odor offset during unrewarded trials (arrowhead). D, The restricted timescale of C shows the onset of divergent auROC values before the average lick onset. The early increase in auROC, which is similar for both rewarded and unrewarded odors (asterisk), may reflect trial-associated multisensory cues and/or arousal (Morrison and Salzman, 2009; Wesson and Wilson, 2010). E, Average auROC values for rewarded trials when spikes times are aligned to odor onset versus lick onset, excluding trials identified with early lick onsets. Slopes of the initial rise were measured from 10% to 90% of the maximum auROC value (dashed lines), and were qualitatively steeper when aligned to odor onset than lick onset (0.021 vs 0.007 auROC/10 ms bin, respectively). Horizontal boxplots show the range of average lick onsets for all sessions included in the average (median, 0.41 s). An asterisk next to the boxplot indicates an identified outlier. Population values represent the mean ± SEM.