Kainate Receptors Regulate the Functional Properties of Young Adult-Born Dentate Granule Cells

Abstract

Both inhibitory and excitatory neurotransmitter receptors can influence maturation and survival of adult-born neurons in the dentate gyrus; yet how these two neurotransmitter systems affect integration of new neurons into the existing circuitry are still not fully characterized. Here we demonstrate that glutamate receptors of the kainate receptor (KAR) subfamily are expressed in adult-born dentate granule cells (abDGCs) and that through their interaction with GABAergic signaling mechanisms alter the functional maturation of adult-born cells during a critical period of their development. Both the intrinsic properties and synaptic connectivity of young abDGCs were affected. Timed KAR loss in a cohort of young adult-born neurons in mice disrupted their performance in a spatial discrimination task but not in a hippocampal-dependent fear conditioning task. Together these results demonstrate the importance of KARs in the proper functional development of young abDGCs.