Somatostatin-positive interneuron (SST-IN) (SST-IN)

Somatostatin-positive interneurons (SST-INs) are a major subclass of GABAergic inhibitory neurons in the mammalian brain, primarily located in the cortex and hippocampus. These neurons are characterized by the expression of the neuropeptide somatostatin and are known for their unique morphology, such as Martinotti cells, which project axons to the distal dendrites of pyramidal neurons (Urban-Ciecko & Barth, 2016). Their primary biological function is to provide feedback and feedforward inhibition to pyramidal cell dendrites, thereby gating excitatory inputs and regulating synaptic plasticity and network oscillations. Dysregulation of SST-INs is strongly linked to the pathophysiology of several neuropsychiatric and neurodegenerative disorders, including major depressive disorder, schizophrenia, and Alzheimer's disease, where a reduction in SST markers is frequently observed (Lin & Sibille, 2015). Pharmacological strategies to modulate SST-IN activity include the use of somatostatin receptor (SSTR) agonists and alpha-5 subunit-selective GABA-A receptor positive allosteric modulators, which aim to restore the inhibitory balance in affected circuits (Fee et al., 2017). Understanding the specific roles of SST-INs in microcircuitry is crucial for developing targeted therapies that can alleviate cognitive and emotional symptoms associated with their dysfunction (Soumier & Sibille, 2014).

Other names

SST+ interneuronSOM-expressing interneuronMartinotti cellSomatostatin-expressing GABAergic neuron

Modulation of GABAergic inhibitory tone and activation of somatostatin receptors (SSTR1-5) to regulate dendritic excitability and circuit homeostasis.