Fig. 6.

DEP20 induces taste aversion to a novel 0.1% saccharin solution, but DEP20-induced LFP oscillations are unrelated to an aversive malaise brain state. A: the daily 15-min intake (in ml) of water (W1–W3) and sodium saccharin (ACQ, Test, and EXT1–EXT3). The arrow (acquisition day, ACQ) indicates the time of injection of LiCl or DEP20, 15 min after consumption of the novel saccharin. The Test session occurred 72 h after ACQ; note that both groups rejected saccharin at similar levels, but during the 3 extinction days (EXT1–EXT3), DEP20 extinguishes the taste aversion faster than LiCl (*P <0.05, RM ANOVA). B: spectrogram (top) of the NAc shell LFP for the BL, Sal, LiCl (0.4 M), and DEP20 epochs, with corresponding hypnogram (bottom). The white trace shows the animal's locomotor activity (scale on right). C: normalized PSD at the beta (15–30 Hz), theta (6–9 Hz), and delta (1–4 Hz) frequency bands across the experiment. D: average locomotor activity (in cm/min) obtained during each epoch shows that LiCl upsets the animal, resulting in distress movements but not stereotypy (not shown) and exploratory locomotion.