Diversity and Function of Somatostatin-Expressing Interneurons in the Cerebral Cortex

• Main Author: Therese Riedemann
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: International Journal of Molecular Sciences
• Subjects: interneuron classification; GABA; Somatostatin; Martinotti cell; mood disorders
• Online Access: https://www.mdpi.com/1422-0067/20/12/2952

Inhibitory interneurons make up around 10−20% of the total neuron population in the cerebral cortex. A hallmark of inhibitory interneurons is their remarkable diversity in terms of morphology, synaptic connectivity, electrophysiological and neurochemical properties. It is generally understood that there are three distinct and non-overlapping interneuron classes in the mouse neocortex, namely, parvalbumin-expressing, 5-HT_3A receptor-expressing and somatostatin-expressing interneuron classes. Each class is, in turn, composed of a multitude of subclasses, resulting in a growing number of interneuron classes and subclasses. In this review, I will focus on the diversity of somatostatin-expressing interneurons (SOM⁺ INs) in the cerebral cortex and elucidate their function in cortical circuits. I will then discuss pathological consequences of a malfunctioning of SOM⁺ INs in neurological disorders such as major depressive disorder, and present future avenues in SOM research and brain pathologies.