A disynaptic feedback network activated by experience promotes the integration of new granule cells

ALVAREZ DD*; GIACOMINI D*; YANG SM; TRINCHERO MF; TEMPRANA SG; BUTTNER KA; BELTRAMONE N; SCHINDER AF; * LOS DOS PRIMEROS AUTORES CONTRIBUYERON EN IGUAL MEDIDA AL TRABAJO

SCIENCE

AMER ASSOC ADVANCEMENT SCIENCE

Año: 2016 vol. 354 p. 459 - 465

0036-8075

Experience shapes the development and connectivity of adult-born granule cells (GCs) through mechanisms that are poorly understood. We examined the remodeling of dentate gyrus microcircuits in mice in an enriched environment (EE). Short exposure to EE during early development of new GCs accelerated their functional integration. This effect was mimicked by in vivo chemogenetic activation of a limited population of mature GCs. Slice recordings showed that mature GCs recruit parvalbumin gamma-aminobutyric acid?releasing interneurons (PV-INs) that feedback onto developing GCs. Accordingly, chemogenetic stimulation of PV-INs or direct depolarization of developing GCs accelerated GC integration, whereas inactivation of PV-INs prevented the effects of EE. Our results reveal a mechanism for dynamic remodeling in which experience activates dentate networks that ?prime? young GCs through a disynaptic feedback loop mediated by PV-INs.