Figure 2.

Amisulpride (▲) and 5-HT (■) versus [³H]5-CT competition binding at 5-HT_7a receptors. The comparatively low affinity of amisulpride for [³H]5-CT, a 5-HT_7a agonist with high intrinsic activity that preferentially binds high affinity sites, in contrast with its higher affinity for [³H]LSD, a very weak partial agonist that labels primarily low affinity antagonist binding sites, suggests that amisulpride is an antagonist at 5-HT_7a receptors.