Kainate receptors regulate the functional properties of young adult-born dentate granule cells

Both inhibitory and excitatory neurotransmitter receptors can influence maturation and survival of adult-born neurons in the dentate gyrus; nevertheless, how these two neurotransmitter systems affect integration of new neurons into the existing circuitry is 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, they alter the functional properties 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. [Display omitted] •Kainate receptors are expressed on developing adult-born dentate granule cells•KARs in adult-born neurons affect their synaptic and intrinsic properties•Timed ablation of KARs during a critical period disrupts spatial discrimination in mice Zhu et al. record from birth-dated, adult-born granule cells in the hippocampus to determine how their properties are affected by KARs. Both the synaptic and intrinsic membrane properties are disrupted during a short developmental window, and mice with a loss of KARs in young neurons have impairments in spatial discrimination.