Discharge of Nb+/Orx+ neuron during S/NS discrimination task. Unit firing of representative Nb+/Orx+ neuron (#BB46D2cell01) shown along with EEG, EMG, and licking response during four sequential trials. A, B, In nonrewarded (no sucrose) Tone 2 trials, the unit discharged minimally before, moderately during Tone 2, and minimally after Tone 2 (NS), when the rat did not lick. C, D, In sucrose-rewarded Tone 1 trials, the unit discharged minimally before, moderately during Tone 1, and at a high rate after Tone 1 (S), when the rat licked to receive a small drop (in the later 2–6 s window in C) or large drop (within the initial 0–2 s window in D) of sucrose. The unit appeared to discharge at highest rates in association with fast EEG activity and EMG activity. Across all trials (n = 18), the average discharge rate was positively correlated with gamma EEG amplitude (r = 0.884) and EMG amplitude (r = 0.674).