Somatostatin receptors

Somatostatin, also known as somatotropin release-inhibiting factor, is a classical endocrine hormone, as well as a neurotransmitter and neuromodulator.  Endogenous somatostatin receptor ligands are somatostatin-14 and somatostatin-28 and these bind to five somatostatin receptor subtypes (sst1−5), each differentially distributed throughout the central nervous system and periphery including the pituitary, pancreas, thyroid, and importantly in the gastrointestinal tract.  Somatostatin has a wide range of physiological effects on neurotransmission, secretion and cell proliferation, including increased locomotor activity, memory and learning and sleep, as well as being involved in changes in autonomic cardiovascular and gastric functions, immune functions and ingestive behaviours.   Somatostatin exerts pro-cognitive effects under healthy and Alzheimer's disease conditions.  Amongst the many peptides involved in the regulation of food-seeking behaviour, somatostatin is the one which plays a determinant role in appetite.

Further reading 

Møller et al (2003) Somatostatin receptors, Biochimica et Biophysica Acta (BBA) - Biomembranes 1616(1) 1 https://doi.org/10.1016/S0005-2736(03)00235-9

Stengel and Taché (2017) Activation of Brain Somatostatin Signaling Suppresses CRF Receptor-Mediated Stress Response.  Front. Neuroscience 11 231 PMID: 28487631

Bosquet et al (2019). Somatostatin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database. IUPHAR/BPS Guide to Pharmacology CITE, 2019(4) https://doi.org/10.2218/gtopdb/F61/2019.4.

Sandoval and Witt (2024) Somatostatin: Linking Cognition and Alzheimer Disease to Therapeutic Targeting. Pharmacol Rev. 76(6) 1291 PMID: 39013601