Binding and pharmacological studies demonstrate that NTSR2 binds neurotensin as well as several other ligands already described for NTSR1. Unlike NTSR1, NTSR2 recognizes, with high affinity, levocabastine, a histamine H1 receptor antagonist previously shown to compete with neurotensin for low-affinity binding sites in brain. NTSR2 may be of physiological importance and a natural agonist for the receptor may exist.