Dentate Gyrus Somatostatin Cells are Required for Contextual Discrimination During Episodic Memory Encoding. (7th October 2020)

• Record Type: Journal Article
• Authors: Morales, Cristian; Morici, Juan Facundo; Espinosa, Nelson; Sacson, Agostina; Lara-Vasquez, Ariel; García-Pérez, M A; Bekinschtein, Pedro; Weisstaub, Noelia V; Fuentealba, Pablo
• Is Part Of: Cerebral cortex. Volume 31:Number 2(2021)
• Page Start: 1046
• Page End: 1059
• Publication Date: 2020-10-07
• Subjects: dentate gyrus -- hippocampus -- interneurons -- memory -- pattern separation; Cerebral cortex -- Periodicals; Brain -- Periodicals; 612.825
• DOI: 10.1093/cercor/bhaa273
• Languages: English
• ISSNs: 1047-3211

Abstract

Abstract: Memory systems ought to store and discriminate representations of similar experiences in order to efficiently guide future decisions. This problem is solved by pattern separation, implemented in the dentate gyrus (DG) by granule cells to support episodic memory formation. Pattern separation is enabled by tonic inhibitory bombardment generated by multiple GABAergic cell populations that strictly maintain low activity levels in granule cells. Somatostatin-expressing cells are one of those interneuron populations, selectively targeting the distal dendrites of granule cells, where cortical multimodal information reaches the DG. Nonetheless, somatostatin cells have very low connection probability and synaptic efficacy with both granule cells and other interneuron types. Hence, the role of somatostatin cells in DG circuitry, particularly in the context of pattern separation, remains uncertain. Here, by using optogenetic stimulation and behavioral tasks in mice, we demonstrate that somatostatin cells are required for the acquisition of both contextual and spatial overlapping memories.