Sst, short for somatostatin, is a cyclic peptide that inhibits the release of hormones and neurotransmitters. It binds to five canonical G protein-coupled SST receptors (SSTR1-SSTR5), negatively regulating cell proliferation and hormone release [4,5]. The GH-IGF-SST system, in which Sst is involved, is crucial for liver growth, development, and also implicated in hepatocarcinogenesis [3]. Genetic models like Sst-Cre mouse lines are valuable tools for studying SST-positive interneurons [2].

In mice, loss of function of excitatory somatostatin-positive neurons in the medial paralemniscal nucleus (MPLSST neurons) impairs self-grooming and post-stress anxiety alleviation. These neurons promote self-grooming, encode reward, and their activation is rewarding, driving reinforcement by activating dopamine neurons in the ventral tegmental area [1].

In conclusion, Sst is essential in regulating hormone release, cell proliferation, and is involved in important biological processes such as self-grooming and anxiety regulation in mice. The study of Sst using mouse models has provided insights into the neurological mechanisms underlying these processes, potentially offering new perspectives for understanding related physiological and pathological conditions.