Figure 4.

The effect of dihydro-β-erythroidine (DHβE) injection (30 nM, ICV), an α4β2 nicotinic acetylcholine receptor antagonist, on conditioning (●) and test (○) amplitudes (top figure) and TC ratios (bottom figure) prior to and following ondansetron (0.33 mg/kg, IP) administration. Asterisks indicate time points of significantly higher conditioning amplitudes as compared to an averaged baseline (b) determined by Fisher's PLSD. Data are mean ± SEM. n = 8. *p < 0.05, **p < 0.01.