Neurotensin receptor 1 (NTR1) is one of three receptors that mediate the effects of the tridecapeptide neurotensin. Neurotensin is synthesized and secreted from neurons in the central neural system (CNS) and from endocrine cells in the gastrointestinal tract.

NTR1 and NTR2 belong to the 7-transmembrane domain, G-protein coupled receptor (GPCR) superfamily while the third neurotensin receptor NTR3 (also called Sortilin) is a type I membrane protein with a large extracellular domain. Both NTR1 and NTR3 bind neurotensin with high affinity while NTR2 binds it with low affinity.¹

NTR1 signals preferentially through Ga_q, resulting in the activation phopholipase C and intracellular Ca²⁺ mobilization, although coupling with G_i/o and to G_s has been observed in some expression systems.

NTR1 is mainly expressed in the brain and gastrointestinal tract. In the brain, NTR1 mediates body temperature regulation, feeding behavior and locomotion regulation. One of the best studied roles of NTR1 is the regulation of dopamine release suggesting that NTR1 can be a suitable target for the development of a new class of anti-psychotics.²  

In the periphery, NTR1 expression has been linked to the control of intestine motility and in the stimulation of growth of the intestine mucosa in both physiological and pathological conditions. NTR1 has been shown to be upregulated in several human cancers where it stimulates tumor growth in response to locally produced neurotensin peptide.³