This work describes the molecular cloning of a variant isoform of the low-affinity levocabastine-sensitive neurotensin receptor isolated from mouse brain. Although the corresponding mRNA encodes for a 282 amino acid protein unable to bind neurotensin after transient transfection in COS-7 cells, this non-functional neurotensin receptor is expressed in cerebral neocortex, cerebellum, olfactory bulb, striatum and hypothalamus with a level similar to that of the full-length low-affinity neurotensin receptor. By contrast, this receptor form is very weakly expressed in mesencephalon and absent in the pituitary, but is the major product in the spinal cord.