Role of 5-HT2A Receptor in Social Cognition in Mice

The serotonergic system and more precisely the serotonin type 2Areceptor (5-HT2AR) is involved in a wide variety of cognitive and emotionalfunctions. In recent studies, it has been found that 5-HT2AR participates inthe prosocial effects of certain drugs. Moreover, the social cognitiveimpairments observed in different psychiatric disorders, such as schizophreniaand Asperger syndrome, have been associated with a hypofunction of the 5-HT2AR.However, the mechanisms underlying this phenotype remain unclear. In thepresent study we analyzed the role of 5-HT2AR in social preference (SP) using agenetically modified mouse model that presents a constitutive depletion ofthe5-HT2AR (KO) compared with their wild type mates (WT). For this purpose weperformed a three-chamber sociability test. We also explore how SP can beaffected by an increased level of serotonin in the central nervous system viachronic administration of fluoxetine. We observed that both male and female KOmice had a lower social preference compared to WT. Thus, the chronicadministration of fluoxetine increased social preference only in WT mice. Theseresults suggest that the serotonergic system could be involved in SP and thatits participation could mediated at least partially by 5-HT2AR.Fil: Sacson, Agostina Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Morici, Juan Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Bekinschtein, Pedro Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Weisstaub, Noelia V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaXXXIV Anual Meeting of Argentine Society for Research in NeurosciencesCarlos PazArgentinaSociedad Argentina de Neurociencia

Dentate Gyrus Somatostatin Cells are Required for Contextual Discrimination During Episodic Memory Encoding

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.Fil: Morales, Cristian. Pontificia Universidad Católica de Chile; ChileFil: Morici, Juan Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Espinosa, Nelson. Pontificia Universidad Católica de Chile; ChileFil: Sacson, Agostina Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Lara Vasquez, Ariel. Pontificia Universidad Católica de Chile; ChileFil: Garciá Pérez, M. A.. Pontificia Universidad Católica de Chile; ChileFil: Bekinschtein, Pedro Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Weisstaub, Noelia V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Fuentealba, Pablo. Pontificia Universidad Católica de Chile; Chil